_B_A_S_H___B_U_I_L_T_I_N_S(1)            General Commands Manual           _B_A_S_H___B_U_I_L_T_I_N_S(1)

NNAAMMEE
       :, ., [, alias, bg, bind, break, builtin, caller, cd, command, compgen,
       complete, compopt, continue, declare, dirs, disown, echo, enable, eval,
       exec,  exit, export, false, fc, fg, getopts, hash, help, history, jobs,
       kill, let, local, logout, mapfile,  popd,  printf,  pushd,  pwd,  read,
       readarray,  readonly, return, set, shift, shopt, source, suspend, test,
       times, trap, true, type, typeset, ulimit, umask, unalias, unset, wait -
       bash built-in commands, see bbaasshh(1)

BBAASSHH BBUUIILLTTIINN CCOOMMMMAANNDDSS
       Unless otherwise noted, each builtin command documented in this section
       as accepting options preceded by -- accepts ---- to signify the end of the
       options.  The ::, ttrruuee, ffaallssee, and tteesstt/[[ builtins do not accept options
       and do not treat ---- specially.  The eexxiitt, llooggoouutt, rreettuurrnn,  bbrreeaakk,  ccoonn--
       ttiinnuuee,  lleett,  and sshhiifftt builtins accept and process arguments beginning
       with -- without requiring ----.  Other builtins that accept arguments  but
       are  not  specified  as accepting options interpret arguments beginning
       with -- as invalid options and require ---- to  prevent  this  interpreta-
       tion.

       :: [_a_r_g_u_m_e_n_t_s]
              No  effect;  the command does nothing beyond expanding _a_r_g_u_m_e_n_t_s
              and performing any specified redirections.  The return status is
              zero.

       .. [--pp _p_a_t_h] _f_i_l_e_n_a_m_e [_a_r_g_u_m_e_n_t_s]
       ssoouurrccee [--pp _p_a_t_h] _f_i_l_e_n_a_m_e [_a_r_g_u_m_e_n_t_s]
              The .. command (ssoouurrccee) reads and execute commands from  _f_i_l_e_n_a_m_e
              in  the current shell environment and returns the exit status of
              the last command executed from _f_i_l_e_n_a_m_e.

              If _f_i_l_e_n_a_m_e does not contain a slash, .. searches for it.  If the
              --pp option is supplied, .. treats _p_a_t_h as a  colon-separated  list
              of  directories in which to find _f_i_l_e_n_a_m_e; otherwise, .. uses the
              entries in PPAATTHH  to  find  the  directory  containing  _f_i_l_e_n_a_m_e.
              _f_i_l_e_n_a_m_e  does  not  need to be executable.  When bbaasshh is not in
              posix mode, it searches the current directory if _f_i_l_e_n_a_m_e is not
              found in PPAATTHH, but does not search the current directory  if  --pp
              is supplied.  If the ssoouurrcceeppaatthh option to the sshhoopptt builtin com-
              mand is turned off, .. does not search PPAATTHH.

              If  any _a_r_g_u_m_e_n_t_s are supplied, they become the positional para-
              meters when _f_i_l_e_n_a_m_e is executed.  Otherwise the positional  pa-
              rameters are unchanged.

              If the --TT option is enabled, .. inherits any trap on DDEEBBUUGG; if it
              is  not,  any DDEEBBUUGG trap string is saved and restored around the
              call to .., and .. unsets the DDEEBBUUGG trap while it executes.  If --TT
              is not set, and the sourced file changes the DDEEBBUUGG trap, the new
              value persists after .. completes.  The return status is the sta-
              tus of the last command executed from _f_i_l_e_n_a_m_e (0 if no commands
              are executed), and non-zero if _f_i_l_e_n_a_m_e is not found  or  cannot
              be read.

       aalliiaass [--pp] [_n_a_m_e[=_v_a_l_u_e] ...]
              With  no  arguments or with the --pp option, aalliiaass prints the list
              of aliases in the form  aalliiaass  _n_a_m_e=_v_a_l_u_e  on  standard  output.
              When arguments are supplied, define an alias for each _n_a_m_e whose
              _v_a_l_u_e  is given.  A trailing space in _v_a_l_u_e causes the next word
              to be checked for alias substitution when the alias is  expanded
              during  command parsing.  For each _n_a_m_e in the argument list for
              which no _v_a_l_u_e is supplied, print the  name  and  value  of  the
              alias  _n_a_m_e.  aalliiaass returns true unless a _n_a_m_e is given (without
              a corresponding =_v_a_l_u_e) for which no alias has been defined.

       bbgg [_j_o_b_s_p_e_c ...]
              Resume each suspended job _j_o_b_s_p_e_c in the background,  as  if  it
              had  been  started with &&.  If _j_o_b_s_p_e_c is not present, the shell
              uses its notion of the _c_u_r_r_e_n_t _j_o_b.  bbgg _j_o_b_s_p_e_c returns 0 unless
              run when job control is disabled or, when run with  job  control
              enabled,  any  specified  _j_o_b_s_p_e_c  was  not found or was started
              without job control.

       bbiinndd [--mm _k_e_y_m_a_p] [--llssvvSSVVXX]
       bbiinndd [--mm _k_e_y_m_a_p] [--qq _f_u_n_c_t_i_o_n] [--uu _f_u_n_c_t_i_o_n] [--rr _k_e_y_s_e_q]
       bbiinndd [--mm _k_e_y_m_a_p] --ff _f_i_l_e_n_a_m_e
       bbiinndd [--mm _k_e_y_m_a_p] --xx _k_e_y_s_e_q[:] _s_h_e_l_l_-_c_o_m_m_a_n_d
       bbiinndd [--mm _k_e_y_m_a_p] _k_e_y_s_e_q:_f_u_n_c_t_i_o_n_-_n_a_m_e
       bbiinndd [--mm _k_e_y_m_a_p] --pp|--PP [_r_e_a_d_l_i_n_e_-_c_o_m_m_a_n_d]
       bbiinndd [--mm _k_e_y_m_a_p] _k_e_y_s_e_q:_r_e_a_d_l_i_n_e_-_c_o_m_m_a_n_d
       bbiinndd _r_e_a_d_l_i_n_e_-_c_o_m_m_a_n_d_-_l_i_n_e
              Display current rreeaaddlliinnee key and function bindings, bind  a  key
              sequence  to a rreeaaddlliinnee function or macro or to a shell command,
              or set a rreeaaddlliinnee variable.  Each non-option argument is  a  key
              binding  or command as it would appear in a rreeaaddlliinnee initializa-
              tion file such as _._i_n_p_u_t_r_c, but each binding or command must  be
              passed    as    a    separate    argument;    e.g.,    \C-x\C-r:
              re-read-init-file.  In the following descriptions, output avail-
              able to be re-read is formatted as commands that would appear in
              a rreeaaddlliinnee initialization file or that would be supplied as  in-
              dividual  arguments  to  a  bbiinndd command.  Options, if supplied,
              have the following meanings:
              --mm _k_e_y_m_a_p
                     Use _k_e_y_m_a_p as the keymap to be affected by the subsequent
                     bindings.  Acceptable _k_e_y_m_a_p names are _e_m_a_c_s_, _e_m_a_c_s_-_s_t_a_n_-
                     _d_a_r_d_, _e_m_a_c_s_-_m_e_t_a_, _e_m_a_c_s_-_c_t_l_x_,  _v_i_,  _v_i_-_m_o_v_e_,  _v_i_-_c_o_m_m_a_n_d,
                     and  _v_i_-_i_n_s_e_r_t.   _v_i is equivalent to _v_i_-_c_o_m_m_a_n_d (_v_i_-_m_o_v_e
                     is also a synonym); _e_m_a_c_s is  equivalent  to  _e_m_a_c_s_-_s_t_a_n_-
                     _d_a_r_d.
              --ll     List the names of all rreeaaddlliinnee functions.
              --pp     Display  rreeaaddlliinnee  function  names and bindings in such a
                     way that they can be used as an argument to a  subsequent
                     bbiinndd  command  or  in a rreeaaddlliinnee initialization file.  If
                     arguments remain after  option  processing,  bbiinndd  treats
                     them  as  rreeaaddlliinnee  command names and restricts output to
                     those names.
              --PP     List current rreeaaddlliinnee function names  and  bindings.   If
                     arguments  remain  after  option  processing, bbiinndd treats
                     them as rreeaaddlliinnee command names and  restricts  output  to
                     those names.
              --ss     Display  rreeaaddlliinnee  key  sequences bound to macros and the
                     strings they output in such a way that they can  be  used
                     as an argument to a subsequent bbiinndd command or in a rreeaadd--
                     lliinnee initialization file.
              --SS     Display  rreeaaddlliinnee  key  sequences bound to macros and the
                     strings they output.
              --vv     Display rreeaaddlliinnee variable names and values in such a  way
                     that they can be used as an argument to a subsequent bbiinndd
                     command or in a rreeaaddlliinnee initialization file.
              --VV     List current rreeaaddlliinnee variable names and values.
              --ff _f_i_l_e_n_a_m_e
                     Read key bindings from _f_i_l_e_n_a_m_e.
              --qq _f_u_n_c_t_i_o_n
                     Display  key  sequences  that  invoke  the named rreeaaddlliinnee
                     _f_u_n_c_t_i_o_n.
              --uu _f_u_n_c_t_i_o_n
                     Unbind all key sequences  bound  to  the  named  rreeaaddlliinnee
                     _f_u_n_c_t_i_o_n.
              --rr _k_e_y_s_e_q
                     Remove any current binding for _k_e_y_s_e_q.
              --xx _k_e_y_s_e_q[[:: ]]_s_h_e_l_l_-_c_o_m_m_a_n_d
                     Cause _s_h_e_l_l_-_c_o_m_m_a_n_d to be executed whenever _k_e_y_s_e_q is en-
                     tered.  The separator between _k_e_y_s_e_q and _s_h_e_l_l_-_c_o_m_m_a_n_d is
                     either  whitespace  or  a  colon  optionally  followed by
                     whitespace.  If the separator is  whitespace,  _s_h_e_l_l_-_c_o_m_-
                     _m_a_n_d  must  be enclosed in double quotes and rreeaaddlliinnee ex-
                     pands any of its special backslash-escapes in  _s_h_e_l_l_-_c_o_m_-
                     _m_a_n_d  before saving it.  If the separator is a colon, any
                     enclosing double quotes are optional, and  rreeaaddlliinnee  does
                     not  expand  the  command string before saving it.  Since
                     the entire key binding expression must be a single  argu-
                     ment,  it  should  be  enclosed  in  single quotes.  When
                     _s_h_e_l_l_-_c_o_m_m_a_n_d is  executed,  the  shell  sets  the  RREEAADD--
                     LLIINNEE__LLIINNEE  variable  to the contents of the rreeaaddlliinnee line
                     buffer and the RREEAADDLLIINNEE__PPOOIINNTT and RREEAADDLLIINNEE__MMAARRKK variables
                     to the current location of the insertion  point  and  the
                     saved  insertion  point  (the  mark),  respectively.  The
                     shell assigns any numeric argument the user  supplied  to
                     the  RREEAADDLLIINNEE__AARRGGUUMMEENNTT  variable.   If there was no argu-
                     ment, that variable is not set.  If the executed  command
                     changes   the   value  of  any  of  RREEAADDLLIINNEE__LLIINNEE,  RREEAADD--
                     LLIINNEE__PPOOIINNTT, or RREEAADDLLIINNEE__MMAARRKK, those new  values  will  be
                     reflected in the editing state.
              --XX     List  all  key  sequences bound to shell commands and the
                     associated commands in a format that can be reused as  an
                     argument to a subsequent bbiinndd command.

              The  return value is 0 unless an unrecognized option is supplied
              or an error occurred.

       bbrreeaakk [_n]
              Exit from within a ffoorr, wwhhiillee, uunnttiill, or sseelleecctt loop.  If  _n  is
              specified, bbrreeaakk exits _n enclosing loops.  _n must be >= 1.  If _n
              is  greater  than  the  number of enclosing loops, all enclosing
              loops are exited.  The return value is 0 unless _n is not greater
              than or equal to 1.

       bbuuiillttiinn _s_h_e_l_l_-_b_u_i_l_t_i_n [_a_r_g_u_m_e_n_t_s]
              Execute the specified shell builtin  _s_h_e_l_l_-_b_u_i_l_t_i_n,  passing  it
              _a_r_g_u_m_e_n_t_s,  and  return  its  exit  status.  This is useful when
              defining a function whose name is the same as a  shell  builtin,
              retaining  the functionality of the builtin within the function.
              The ccdd builtin is commonly redefined this way.  The return  sta-
              tus is false if _s_h_e_l_l_-_b_u_i_l_t_i_n is not a shell builtin command.

       ccaalllleerr [_e_x_p_r]
              Returns the context of any active subroutine call (a shell func-
              tion or a script executed with the .. or ssoouurrccee builtins).

              Without  _e_x_p_r,  ccaalllleerr displays the line number and source file-
              name of the current subroutine call.  If a non-negative  integer
              is supplied as _e_x_p_r, ccaalllleerr displays the line number, subroutine
              name, and source file corresponding to that position in the cur-
              rent  execution call stack.  This extra information may be used,
              for example, to print a stack trace.  The current frame is frame
              0.

              The return value is 0 unless the shell is not executing  a  sub-
              routine  call or _e_x_p_r does not correspond to a valid position in
              the call stack.

       ccdd [--LL] [--@@] [_d_i_r]
       ccdd --PP [--ee] [--@@] [_d_i_r]
              Change the current directory to _d_i_r.  if _d_i_r  is  not  supplied,
              the  value of the HHOOMMEE shell variable is used as _d_i_r.  The vari-
              able CCDDPPAATTHH exists, and _d_i_r does not begin with a slash (/),  ccdd
              uses it as a search path: the shell searches each directory name
              in  CCDDPPAATTHH  for  _d_i_r.  Alternative directory names in CCDDPPAATTHH are
              separated by a colon (:).  A null directory name  in  CCDDPPAATTHH  is
              the same as the current directory, i.e.,

              The  --PP option causes ccdd to use the physical directory structure
              by resolving symbolic links while traversing _d_i_r and before pro-
              cessing instances of _._. in _d_i_r (see also the --PP  option  to  the
              sseett builtin command).

              The  --LL  option  forces ccdd to follow symbolic links by resolving
              the link after processing instances of _._. in _d_i_r.  If _._. appears
              in _d_i_r, ccdd processes it by  removing  the  immediately  previous
              pathname component from _d_i_r, back to a slash or the beginning of
              _d_i_r,  and  verifying that the portion of _d_i_r it has processed to
              that point is still a valid directory name  after  removing  the
              pathname component.  If it is not a valid directory name, ccdd re-
              turns  a  non-zero status.  If neither --LL nor --PP is supplied, ccdd
              behaves as if --LL had been supplied.

              If the --ee option is supplied with --PP, and ccdd cannot successfully
              determine the current working directory after a  successful  di-
              rectory change, it returns a non-zero status.

              On  systems that support it, the --@@ option presents the extended
              attributes associated with a file as a directory.

              An argument of -- is converted to $$OOLLDDPPWWDD before  attempting  the
              directory change.

              If  ccdd  uses  a non-empty directory name from CCDDPPAATTHH, or if -- is
              the first argument, and the directory change is  successful,  ccdd
              writes the absolute pathname of the new working directory to the
              standard output.

              If  the directory change is successful, ccdd sets the value of the
              PPWWDD environment variable to the new directory name, and sets the
              OOLLDDPPWWDD environment variable to the value of the current  working
              directory before the change.

              The  return  value  is  true  if  the directory was successfully
              changed; false otherwise.

       ccoommmmaanndd [--ppVVvv] _c_o_m_m_a_n_d [_a_r_g ...]
              The ccoommmmaanndd builtin runs _c_o_m_m_a_n_d with _a_r_g_s suppressing the  nor-
              mal shell function lookup for _c_o_m_m_a_n_d.  Only builtin commands or
              commands  found  in the PPAATTHH named _c_o_m_m_a_n_d are executed.  If the
              --pp option is supplied, the search for _c_o_m_m_a_n_d is performed using
              a default value for PPAATTHH that is guaranteed to find all  of  the
              standard utilities.

              If  either the --VV or --vv option is supplied, ccoommmmaanndd prints a de-
              scription of _c_o_m_m_a_n_d.  The --vv option displays a single word  in-
              dicating  the command or filename used to invoke _c_o_m_m_a_n_d; the --VV
              option produces a more verbose description.

              If the --VV or --vv option is supplied, the exit status is  zero  if
              _c_o_m_m_a_n_d  was  found,  and non-zero if not.  If neither option is
              supplied and an error occurred or _c_o_m_m_a_n_d cannot be  found,  the
              exit  status  is 127.  Otherwise, the exit status of the ccoommmmaanndd
              builtin is the exit status of _c_o_m_m_a_n_d.

       ccoommppggeenn [--VV _v_a_r_n_a_m_e] [_o_p_t_i_o_n] [_w_o_r_d]
              Generate possible completion matches for _w_o_r_d according  to  the
              _o_p_t_i_o_ns,  which  may  be  any  option  accepted  by the ccoommpplleettee
              builtin with the exceptions of --pp, --rr, --DD, --EE, and --II, and write
              the matches to the standard output.

              If the --VV option is supplied, ccoommppggeenn stores the generated  com-
              pletions  into  the  indexed  array  variable _v_a_r_n_a_m_e instead of
              writing them to the standard output.

              When using the --FF or --CC options, the various shell variables set
              by the programmable completion facilities, while available, will
              not have useful values.

              The matches will be generated in the same way as if the program-
              mable completion code had generated them directly from a comple-
              tion specification with the same flags.  If _w_o_r_d  is  specified,
              only  those  completions  matching  _w_o_r_d  will  be  displayed or
              stored.

              The return value is true unless an invalid option  is  supplied,
              or no matches were generated.

       ccoommpplleettee [--aabbccddeeffggjjkkssuuvv] [--oo _c_o_m_p_-_o_p_t_i_o_n] [--DDEEII] [--AA _a_c_t_i_o_n]
              [--GG _g_l_o_b_p_a_t] [--WW _w_o_r_d_l_i_s_t] [--FF _f_u_n_c_t_i_o_n] [--CC _c_o_m_m_a_n_d]
              [--XX _f_i_l_t_e_r_p_a_t] [--PP _p_r_e_f_i_x] [--SS _s_u_f_f_i_x] _n_a_m_e [_n_a_m_e ...]
       ccoommpplleettee --pprr [--DDEEII] [_n_a_m_e ...]
              Specify how arguments to each _n_a_m_e should be completed.

              If the --pp option is supplied, or if no options or _n_a_m_es are sup-
              plied,  print  existing  completion specifications in a way that
              allows them to be reused as input.  The --rr option removes a com-
              pletion specification for each _n_a_m_e, or, if no  _n_a_m_es  are  sup-
              plied, all completion specifications.

              The  --DD option indicates that other supplied options and actions
              should apply to the command completion; that is, completion  at-
              tempted on a command for which no completion has previously been
              defined.   The  --EE  option indicates that other supplied options
              and actions should apply to command completion; that is, comple-
              tion attempted on a blank line.  The --II  option  indicates  that
              other supplied options and actions should apply to completion on
              the  initial non-assignment word on the line, or after a command
              delimiter such as ;; or ||, which is usually command name  comple-
              tion.   If  multiple  options  are supplied, the --DD option takes
              precedence over --EE, and both take precedence over --II.  If any of
              --DD, --EE, or --II are supplied, any other  _n_a_m_e  arguments  are  ig-
              nored; these completions only apply to the case specified by the
              option.

              The process of applying these completion specifications when at-
              tempting word completion  is described in _b_a_s_h(1).

              Other  options,  if specified, have the following meanings.  The
              arguments to the --GG, --WW, and --XX options (and, if necessary,  the
              --PP  and --SS options) should be quoted to protect them from expan-
              sion before the ccoommpplleettee builtin is invoked.

              --oo _c_o_m_p_-_o_p_t_i_o_n
                      The _c_o_m_p_-_o_p_t_i_o_n controls several aspects  of  the  comp-
                      spec's  behavior beyond the simple generation of comple-
                      tions.  _c_o_m_p_-_o_p_t_i_o_n may be one of:
                      bbaasshhddeeffaauulltt
                              Perform the rest of the default bbaasshh completions
                              if the compspec generates no matches.
                      ddeeffaauulltt Use rreeaaddlliinnee's default  filename  completion  if
                              the compspec generates no matches.
                      ddiirrnnaammeess
                              Perform  directory  name completion if the comp-
                              spec generates no matches.
                      ffiilleennaammeess
                              Tell rreeaaddlliinnee that the compspec generates  file-
                              names,  so  it can perform any filename-specific
                              processing (such as adding a slash to  directory
                              names,  quoting special characters, or suppress-
                              ing trailing spaces).  This is  intended  to  be
                              used with shell functions.
                      ffuullllqquuoottee
                              Tell  rreeaaddlliinnee  to quote all the completed words
                              even if they are not filenames.
                      nnooqquuoottee Tell rreeaaddlliinnee not to quote the  completed  words
                              if  they are filenames (quoting filenames is the
                              default).
                      nnoossoorrtt  Tell rreeaaddlliinnee not to sort the list  of  possible
                              completions alphabetically.
                      nnoossppaaccee Tell  rreeaaddlliinnee  not  to  append a space (the de-
                              fault) to words completed  at  the  end  of  the
                              line.
                      pplluussddiirrss
                              After  generating  any  matches  defined  by the
                              compspec, attempt directory name completion  and
                              add  any matches to the results of the other ac-
                              tions.
              --AA _a_c_t_i_o_n
                      The _a_c_t_i_o_n may be one of the  following  to  generate  a
                      list of possible completions:
                      aalliiaass   Alias names.  May also be specified as --aa.
                      aarrrraayyvvaarr
                              Array variable names.
                      bbiinnddiinngg RReeaaddlliinnee key binding names.
                      bbuuiillttiinn Names  of  shell  builtin commands.  May also be
                              specified as --bb.
                      ccoommmmaanndd Command names.  May also be specified as --cc.
                      ddiirreeccttoorryy
                              Directory names.  May also be specified as --dd.
                      ddiissaabblleedd
                              Names of disabled shell builtins.
                      eennaabblleedd Names of enabled shell builtins.
                      eexxppoorrtt  Names of exported shell variables.  May also  be
                              specified as --ee.
                      ffiillee    File  and directory names, similar to rreeaaddlliinnee's
                              filename completion.  May also be  specified  as
                              --ff.
                      ffuunnccttiioonn
                              Names of shell functions.
                      ggrroouupp   Group names.  May also be specified as --gg.
                      hheellppttooppiicc
                              Help topics as accepted by the hheellpp builtin.
                      hhoossttnnaammee
                              Hostnames,  as  taken from the file specified by
                              the HHOOSSTTFFIILLEE shell variable.
                      jjoobb     Job names, if job control is active.   May  also
                              be specified as --jj.
                      kkeeyywwoorrdd Shell  reserved words.  May also be specified as
                              --kk.
                      rruunnnniinngg Names of running jobs, if job control is active.
                      sseerrvviiccee Service names.  May also be specified as --ss.
                      sseettoopptt  Valid arguments for the --oo  option  to  the  sseett
                              builtin.
                      sshhoopptt   Shell  option  names  as  accepted  by the sshhoopptt
                              builtin.
                      ssiiggnnaall  Signal names.
                      ssttooppppeedd Names of stopped jobs, if job control is active.
                      uusseerr    User names.  May also be specified as --uu.
                      vvaarriiaabbllee
                              Names of all shell variables.  May also be spec-
                              ified as --vv.
              --CC _c_o_m_m_a_n_d
                      _c_o_m_m_a_n_d is executed in a subshell environment,  and  its
                      output  is  used as the possible completions.  Arguments
                      are passed as with the --FF option.
              --FF _f_u_n_c_t_i_o_n
                      The shell function _f_u_n_c_t_i_o_n is executed in  the  current
                      shell  environment.   When the function is executed, the
                      first argument ($$11) is the name of the command whose ar-
                      guments are being completed, the second argument ($$22) is
                      the word being completed, and the third argument ($$33) is
                      the word preceding the word being completed on the  cur-
                      rent command line.  When _f_u_n_c_t_i_o_n finishes, programmable
                      completion  retrieves  the possible completions from the
                      value of the CCOOMMPPRREEPPLLYY array variable.
              --GG _g_l_o_b_p_a_t
                      Expand the pathname expansion pattern _g_l_o_b_p_a_t to  gener-
                      ate the possible completions.
              --PP _p_r_e_f_i_x
                      Add  _p_r_e_f_i_x to the beginning of each possible completion
                      after all other options have been applied.
              --SS _s_u_f_f_i_x
                      Append _s_u_f_f_i_x to  each  possible  completion  after  all
                      other options have been applied.
              --WW _w_o_r_d_l_i_s_t
                      Split  the _w_o_r_d_l_i_s_t using the characters in the IIFFSS spe-
                      cial variable as delimiters, and expand  each  resulting
                      word.   Shell quoting is honored within _w_o_r_d_l_i_s_t, in or-
                      der to provide a mechanism  for  the  words  to  contain
                      shell  metacharacters or characters in the value of IIFFSS.
                      The possible completions are the members of  the  resul-
                      tant  list  which  match a prefix of the word being com-
                      pleted.
              --XX _f_i_l_t_e_r_p_a_t
                      _f_i_l_t_e_r_p_a_t is a pattern as used for  pathname  expansion.
                      It is applied to the list of possible completions gener-
                      ated  by  the  preceding options and arguments, and each
                      completion matching _f_i_l_t_e_r_p_a_t is removed from the  list.
                      A  leading  !!  in _f_i_l_t_e_r_p_a_t negates the pattern; in this
                      case, any completion not matching _f_i_l_t_e_r_p_a_t is removed.

              The return value is true unless an invalid option  is  supplied,
              an option other than --pp, --rr, --DD, --EE, or --II is supplied without a
              _n_a_m_e  argument, an attempt is made to remove a completion speci-
              fication for a _n_a_m_e for which no specification exists, or an er-
              ror occurs adding a completion specification.

       ccoommppoopptt [--oo _o_p_t_i_o_n] [--DDEEII] [++oo _o_p_t_i_o_n] [_n_a_m_e]
              Modify completion options for each _n_a_m_e  according  to  the  _o_p_-
              _t_i_o_ns, or for the currently-executing completion if no _n_a_m_es are
              supplied.   If  no  _o_p_t_i_o_ns are supplied, display the completion
              options for each _n_a_m_e or the current completion.   The  possible
              values  of  _o_p_t_i_o_n  are those valid for the ccoommpplleettee builtin de-
              scribed above.

              The --DD option indicates that other supplied options should apply
              to the command completion; the --EE option  indicates  that  other
              supplied  options should apply to command completion; and the --II
              option indicates that other supplied  options  should  apply  to
              completion  on  the  initial word on the line.  These are deter-
              mined in the same way as the ccoommpplleettee builtin.

              If multiple options are supplied, the --DD option takes precedence
              over --EE, and both take precedence over --II.

              The return value is true unless an invalid option  is  supplied,
              an attempt is made to modify the options for a _n_a_m_e for which no
              completion specification exists, or an output error occurs.

       ccoonnttiinnuuee [_n]
              ccoonnttiinnuuee resumes the next iteration of the enclosing ffoorr, wwhhiillee,
              uunnttiill,  or sseelleecctt loop.  If _n is specified, bbaasshh resumes the _nth
              enclosing loop.  _n must be >= 1.  If _n is greater than the  num-
              ber  of  enclosing  loops,  the shell resumes the last enclosing
              loop (the loop).  The return value is 0 unless _n is not  greater
              than or equal to 1.

       ddeeccllaarree [--aaAAffFFggiiIIllnnrrttuuxx] [--pp] [_n_a_m_e[=_v_a_l_u_e] ...]
       ttyyppeesseett [--aaAAffFFggiiIIllnnrrttuuxx] [--pp] [_n_a_m_e[=_v_a_l_u_e] ...]
              Declare  variables and/or give them attributes.  If no _n_a_m_es are
              given then display the values of variables or functions.  The --pp
              option will display the attributes  and  values  of  each  _n_a_m_e.
              When  --pp  is used with _n_a_m_e arguments, additional options, other
              than --ff and --FF, are ignored.

              When --pp is supplied without _n_a_m_e arguments, ddeeccllaarree will display
              the attributes and values of all variables having the attributes
              specified by the additional options.  If no  other  options  are
              supplied with --pp, ddeeccllaarree will display the attributes and values
              of  all shell variables.  The --ff option restricts the display to
              shell functions.

              The --FF option inhibits the display of function definitions; only
              the function name and attributes are printed.  If  the  eexxttddeebbuugg
              shell  option  is  enabled using sshhoopptt, the source file name and
              line number where each _n_a_m_e is defined are  displayed  as  well.
              The --FF option implies --ff.

              The  --gg option forces variables to be created or modified at the
              global scope, even when ddeeccllaarree is executed in a shell function.
              It is ignored when ddeeccllaarree is not executed in a shell function.

              The --II option causes local variables to inherit  the  attributes
              (except  the  _n_a_m_e_r_e_f attribute) and value of any existing vari-
              able with the same _n_a_m_e at a surrounding scope.  If there is  no
              existing variable, the local variable is initially unset.

              The  following  options  can be used to restrict output to vari-
              ables with the specified attribute or to give variables  attrib-
              utes:
              --aa     Each  _n_a_m_e  is  an  indexed array variable (see AArrrraayyss in
                     _b_a_s_h(1)).
              --AA     Each _n_a_m_e is an associative array variable (see AArrrraayyss in
                     _b_a_s_h(1)).
              --ff     Each _n_a_m_e refers to a shell function.
              --ii     The variable is treated as an integer; arithmetic evalua-
                     tion (see AARRIITTHHMMEETTIICC EEVVAALLUUAATTIIOONN in _b_a_s_h(1)) is  performed
                     when the variable is assigned a value.
              --ll     When  the  variable  is  assigned a value, all upper-case
                     characters are converted to lower-case.   The  upper-case
                     attribute is disabled.
              --nn     Give  each  _n_a_m_e  the _n_a_m_e_r_e_f attribute, making it a name
                     reference to another variable.  That  other  variable  is
                     defined  by  the  value of _n_a_m_e.  All references, assign-
                     ments, and attribute modifications to _n_a_m_e, except  those
                     using  or changing the --nn attribute itself, are performed
                     on the variable referenced by _n_a_m_e's value.  The  nameref
                     attribute cannot be applied to array variables.
              --rr     Make _n_a_m_es readonly.  These names cannot then be assigned
                     values by subsequent assignment statements or unset.
              --tt     Give each _n_a_m_e the _t_r_a_c_e attribute.  Traced functions in-
                     herit  the DDEEBBUUGG and RREETTUURRNN traps from the calling shell.
                     The trace attribute has no special meaning for variables.
              --uu     When the variable is assigned  a  value,  all  lower-case
                     characters  are  converted to upper-case.  The lower-case
                     attribute is disabled.
              --xx     Mark each _n_a_m_e for export to subsequent commands via  the
                     environment.

              Using instead of turns off the specified attribute instead, with
              the  exceptions  that ++aa and ++AA may not be used to destroy array
              variables and ++rr will not remove the readonly attribute.

              When used in a function, ddeeccllaarree and ttyyppeesseett make each _n_a_m_e  lo-
              cal,  as  with  the  llooccaall command, unless the --gg option is sup-
              plied.  If a variable name is followed by =_v_a_l_u_e, the  value  of
              the  variable is set to _v_a_l_u_e.  When using --aa or --AA and the com-
              pound assignment syntax to create  array  variables,  additional
              attributes do not take effect until subsequent assignments.

              The  return  value is 0 unless an invalid option is encountered,
              an attempt is made to define a function using an attempt is made
              to assign a value to a readonly variable, an attempt is made  to
              assign  a  value to an array variable without using the compound
              assignment syntax (see AArrrraayyss in _b_a_s_h(1)), one of the  _n_a_m_e_s  is
              not  a valid shell variable name, an attempt is made to turn off
              readonly status for a readonly variable, an attempt is  made  to
              turn  off  array  status for an array variable, or an attempt is
              made to display a non-existent function with --ff.

       ddiirrss [[--ccllppvv]] [[++_n]] [[--_n]]
              Without options, display the list of currently remembered direc-
              tories.  The default display is on a single line with  directory
              names  separated  by  spaces.  Directories are added to the list
              with the ppuusshhdd command; the ppooppdd command  removes  entries  from
              the  list.   The current directory is always the first directory
              in the stack.

              Options, if supplied, have the following meanings:
              --cc     Clears the directory stack by deleting  all  of  the  en-
                     tries.
              --ll     Produces  a  listing  using  full  pathnames; the default
                     listing format uses a tilde to denote the home directory.
              --pp     Print the directory stack with one entry per line.
              --vv     Print the directory stack with one entry per  line,  pre-
                     fixing each entry with its index in the stack.
              ++_n     Displays the _nth entry counting from the left of the list
                     shown by ddiirrss when invoked without options, starting with
                     zero.
              --_n     Displays  the  _nth  entry  counting from the right of the
                     list shown by ddiirrss when invoked without options, starting
                     with zero.

              The return value is 0 unless an invalid option is supplied or  _n
              indexes beyond the end of the directory stack.

       ddiissoowwnn [--aarr] [--hh] [_i_d ...]
              Without  options,  remove each _i_d from the table of active jobs.
              Each _i_d may be a job specification _j_o_b_s_p_e_c or a process ID  _p_i_d;
              if _i_d is a _p_i_d, ddiissoowwnn uses the job containing _p_i_d as _j_o_b_s_p_e_c.

              If  the  --hh  option is supplied, ddiissoowwnn does not remove the jobs
              corresponding to each _i_d from the jobs table, but  rather  marks
              them  so  the shell does not send SSIIGGHHUUPP to the job if the shell
              receives a SSIIGGHHUUPP.

              If no _i_d is supplied, the --aa option means to remove or mark  all
              jobs; the --rr option without an _i_d argument removes or marks run-
              ning  jobs.  If no _i_d is supplied, and neither the --aa nor the --rr
              option is supplied, ddiissoowwnn removes or marks the current job.

              The return value is 0 unless an _i_d does not specify a valid job.

       eecchhoo [--nneeEE] [_a_r_g ...]
              Output the _a_r_gs, separated by spaces,  followed  by  a  newline.
              The  return  status  is 0 unless a write error occurs.  If --nn is
              specified, the trailing newline is not printed.

              If the --ee option is given, eecchhoo interprets the  following  back-
              slash-escaped characters.  The --EE option disables interpretation
              of  these  escape characters, even on systems where they are in-
              terpreted by default.   The  xxppgg__eecchhoo  shell  option  determines
              whether or not eecchhoo interprets any options and expands these es-
              cape  characters.  eecchhoo does not interpret ---- to mean the end of
              options.

              eecchhoo interprets the following escape sequences:
              \\aa     alert (bell)
              \\bb     backspace
              \\cc     suppress further output
              \\ee
              \\EE     an escape character
              \\ff     form feed
              \\nn     new line
              \\rr     carriage return
              \\tt     horizontal tab
              \\vv     vertical tab
              \\\\     backslash
              \\00_n_n_n  The eight-bit character whose value is  the  octal  value
                     _n_n_n (zero to three octal digits).
              \\xx_H_H   The  eight-bit  character  whose value is the hexadecimal
                     value _H_H (one or two hex digits).
              \\uu_H_H_H_H The Unicode (ISO/IEC 10646) character whose value is  the
                     hexadecimal value _H_H_H_H (one to four hex digits).
              \\UU_H_H_H_H_H_H_H_H
                     The  Unicode (ISO/IEC 10646) character whose value is the
                     hexadecimal value _H_H_H_H_H_H_H_H (one to eight hex digits).

              eecchhoo writes any unrecognized  backslash-escaped  characters  un-
              changed.

       eennaabbllee [--aa] [--ddnnppss] [--ff _f_i_l_e_n_a_m_e] [_n_a_m_e ...]
              Enable  and disable builtin shell commands.  Disabling a builtin
              allows an executable file which has the same  name  as  a  shell
              builtin  to be executed without specifying a full pathname, even
              though the shell normally searches for builtins before files.

              If --nn is supplied, each _n_a_m_e is disabled; otherwise,  _n_a_m_es  are
              enabled.   For  example, to use the tteesstt binary found using PPAATTHH
              instead of the shell builtin version, run

              If no _n_a_m_e arguments are supplied, or if the --pp option  is  sup-
              plied, print a list of shell builtins.  With no other option ar-
              guments, the list consists of all enabled shell builtins.  If --nn
              is  supplied,  print only disabled builtins.  If --aa is supplied,
              the list printed includes all builtins, with  an  indication  of
              whether or not each is enabled.  The --ss option means to restrict
              the output to the POSIX _s_p_e_c_i_a_l builtins.

              The  --ff  option  means to load the new builtin command _n_a_m_e from
              shared object _f_i_l_e_n_a_m_e, on systems that support dynamic loading.
              If _f_i_l_e_n_a_m_e does not contain a slash, BBaasshh will use the value of
              the BBAASSHH__LLOOAADDAABBLLEESS__PPAATTHH variable as a  colon-separated  list  of
              directories  in  which  to search for _f_i_l_e_n_a_m_e.  The default for
              BBAASSHH__LLOOAADDAABBLLEESS__PPAATTHH is  system-dependent,  and  may  include  to
              force  a  search  of  the current directory.  The --dd option will
              delete a builtin previously loaded with --ff.  If _-_s is used  with
              _-_f, the new builtin becomes a POSIX special builtin.

              If  no  options  are supplied and a _n_a_m_e is not a shell builtin,
              eennaabbllee will attempt to load _n_a_m_e  from  a  shared  object  named
              _n_a_m_e, as if the command were

              The  return  value  is 0 unless a _n_a_m_e is not a shell builtin or
              there is an error loading a new builtin from a shared object.

       eevvaall [_a_r_g ...]
              Concatenate the _a_r_gs together into a single command,  separating
              them with spaces.  BBaasshh then reads and execute this command, and
              returns  its exit status as the return status of eevvaall.  If there
              are no _a_r_g_s, or only null arguments, eevvaall returns 0.

       eexxeecc [--ccll] [--aa _n_a_m_e] [_c_o_m_m_a_n_d [_a_r_g_u_m_e_n_t_s]]
              If _c_o_m_m_a_n_d is specified, it replaces the shell without  creating
              a  new  process.  _c_o_m_m_a_n_d cannot be a shell builtin or function.
              The _a_r_g_u_m_e_n_t_s become the arguments to _c_o_m_m_a_n_d.  If the --ll option
              is supplied, the shell places a dash at the beginning of the ze-
              roth argument passed to _c_o_m_m_a_n_d.  This is  what  _l_o_g_i_n(1)  does.
              The  --cc option causes _c_o_m_m_a_n_d to be executed with an empty envi-
              ronment.  If --aa is supplied, the shell passes _n_a_m_e as the zeroth
              argument to the executed command.

              If _c_o_m_m_a_n_d cannot be executed for some reason, a non-interactive
              shell exits, unless the eexxeeccffaaiill shell option  is  enabled.   In
              that  case,  it returns a non-zero status.  An interactive shell
              returns a non-zero status if the file  cannot  be  executed.   A
              subshell exits unconditionally if eexxeecc fails.

              If _c_o_m_m_a_n_d is not specified, any redirections take effect in the
              current  shell, and the return status is 0.  If there is a redi-
              rection error, the return status is 1.

       eexxiitt [_n]
              Cause the shell to exit with a status of _n.  If  _n  is  omitted,
              the  exit status is that of the last command executed.  Any trap
              on EEXXIITT is executed before the shell terminates.

       eexxppoorrtt [--ffnn] [_n_a_m_e[=_v_a_l_u_e]] ...
       eexxppoorrtt --pp
              The supplied _n_a_m_e_s are marked for automatic export to the  envi-
              ronment  of subsequently executed commands.  If the --ff option is
              given, the _n_a_m_e_s refer to functions.

              The --nn option unexports, or removes the export  attribute,  from
              each  _n_a_m_e.   If no _n_a_m_e_s are given, or if the --pp option is sup-
              plied, eexxppoorrtt prints a list of names of all  exported  variables
              on the standard output.

              eexxppoorrtt  allows  the value of a variable to be set when it is ex-
              ported or unexported by following the variable name with =_v_a_l_u_e.
              This sets the value of the variable to _v_a_l_u_e while modifying the
              export attribute.  eexxppoorrtt returns an exit status of 0 unless  an
              invalid  option  is encountered, one of the _n_a_m_e_s is not a valid
              shell variable name, or --ff is supplied with a _n_a_m_e that is not a
              function.

       ffaallssee  Does nothing; returns a non-zero status.

       ffcc [--ee _e_n_a_m_e] [--llnnrr] [_f_i_r_s_t] [_l_a_s_t]
       ffcc --ss [_p_a_t=_r_e_p] [_c_m_d]
              The first form selects a range of commands from  _f_i_r_s_t  to  _l_a_s_t
              from  the  history  list  and  displays or edits and re-executes
              them.  _F_i_r_s_t and _l_a_s_t may be specified as a  string  (to  locate
              the  last command beginning with that string) or as a number (an
              index into the history list, where a negative number is used  as
              an offset from the current command number).

              When listing, a _f_i_r_s_t or _l_a_s_t of 0 is equivalent to -1 and -0 is
              equivalent to the current command (usually the ffcc command); oth-
              erwise  0 is equivalent to -1 and -0 is invalid.  If _l_a_s_t is not
              specified, it is set to the current command for listing (so that
              prints the last 10 commands) and to _f_i_r_s_t otherwise.   If  _f_i_r_s_t
              is  not specified, it is set to the previous command for editing
              and -16 for listing.

              If the --ll option is supplied, the commands  are  listed  on  the
              standard  output.   The --nn option suppresses the command numbers
              when listing.  The --rr option reverses the order of the commands.

              Otherwise, ffcc invokes the editor named by _e_n_a_m_e on a  file  con-
              taining  those  commands.  If _e_n_a_m_e is not supplied, ffcc uses the
              value of the FFCCEEDDIITT variable, and the value of EEDDIITTOORR if  FFCCEEDDIITT
              is  not set.  If neither variable is set, ffcc uses _v_i_. When edit-
              ing is complete, ffcc reads the file containing  the  edited  com-
              mands and echoes and executes them.

              In  the second form, ffcc re-executes _c_o_m_m_a_n_d after replacing each
              instance of _p_a_t with _r_e_p.  _C_o_m_m_a_n_d is interpreted  the  same  as
              _f_i_r_s_t above.

              A  useful  alias  to use with ffcc is so that typing runs the last
              command beginning with and typing re-executes the last command.

              If the first form is used, the return value is  zero  unless  an
              invalid  option  is encountered or _f_i_r_s_t or _l_a_s_t specify history
              lines out of range.  When editing and  re-executing  a  file  of
              commands, the return value is the value of the last command exe-
              cuted or failure if an error occurs with the temporary file.  If
              the second form is used, the return status is that of the re-ex-
              ecuted  command, unless _c_m_d does not specify a valid history en-
              try, in which case ffcc returns a non-zero status.

       ffgg [_j_o_b_s_p_e_c]
              Resume _j_o_b_s_p_e_c in the foreground, and make it the  current  job.
              If  _j_o_b_s_p_e_c  is  not  present, ffgg uses the shell's notion of the
              _c_u_r_r_e_n_t _j_o_b.  The return value is that  of  the  command  placed
              into  the foreground, or failure if run when job control is dis-
              abled or, when run with job control enabled, if _j_o_b_s_p_e_c does not
              specify a valid job or _j_o_b_s_p_e_c specifies a job that was  started
              without job control.

       ggeettooppttss _o_p_t_s_t_r_i_n_g _n_a_m_e [_a_r_g ...]
              ggeettooppttss  is  used  by shell scripts and functions to parse posi-
              tional parameters and obtain options and their arguments.   _o_p_t_-
              _s_t_r_i_n_g  contains  the  option  characters to be recognized; if a
              character is followed by a colon, the option is expected to have
              an argument, which should be separated from it by  white  space.
              The colon and question mark characters may not be used as option
              characters.

              Each  time  it is invoked, ggeettooppttss places the next option in the
              shell variable _n_a_m_e, initializing _n_a_m_e if it does not exist, and
              the index of the next argument to be processed into the variable
              OOPPTTIINNDD.  OOPPTTIINNDD is initialized to 1 each time  the  shell  or  a
              shell  script  is invoked.  When an option requires an argument,
              ggeettooppttss places that argument into the variable OOPPTTAARRGG.

              The shell does not reset OOPPTTIINNDD automatically; it must be  manu-
              ally  reset  between  multiple  calls to ggeettooppttss within the same
              shell invocation to use a new set of parameters.

              When it reaches the end of options, ggeettooppttss exits with a  return
              value  greater  than  zero.   OOPPTTIINNDD  is set to the index of the
              first non-option argument, and _n_a_m_e is set to ?.

              ggeettooppttss normally parses the positional parameters, but  if  more
              arguments  are  supplied as _a_r_g values, ggeettooppttss parses those in-
              stead.

              ggeettooppttss can report errors in two ways.  If the  first  character
              of  _o_p_t_s_t_r_i_n_g  is  a colon, ggeettooppttss uses _s_i_l_e_n_t error reporting.
              In normal operation, ggeettooppttss prints diagnostic messages when  it
              encounters  invalid options or missing option arguments.  If the
              variable OOPPTTEERRRR is set to 0, ggeettooppttss does not display any  error
              messages,  even  if  the  first  character of _o_p_t_s_t_r_i_n_g is not a
              colon.

              If ggeettooppttss detects an invalid option, it places ? into _n_a_m_e and,
              if not silent, prints an error message and  unsets  OOPPTTAARRGG.   If
              ggeettooppttss  is silent, it assigns the option character found to OOPP--
              TTAARRGG and does not print a diagnostic message.

              If a required argument is not found, and ggeettooppttss is not  silent,
              it sets the value of _n_a_m_e to a question mark (??), unsets OOPPTTAARRGG,
              and  prints a diagnostic message.  If ggeettooppttss is silent, it sets
              the value of _n_a_m_e to a colon (::) and sets OOPPTTAARRGG to  the  option
              character found.

              ggeettooppttss  returns true if an option, specified or unspecified, is
              found.  It returns false if the end of options is encountered or
              an error occurs.

       hhaasshh [--llrr] [--pp _f_i_l_e_n_a_m_e] [--ddtt] [_n_a_m_e]
              Each time hhaasshh is invoked, it remembers the full pathname of the
              command _n_a_m_e as  determined  by  searching  the  directories  in
              $$PPAATTHH.   Any previously-remembered pathname associated with _n_a_m_e
              is discarded.  If the --pp option is supplied, hhaasshh uses  _f_i_l_e_n_a_m_e
              as the full pathname of the command.

              The  --rr  option  causes the shell to forget all remembered loca-
              tions.  Assigning to the PPAATTHH variable also  clears  all  hashed
              filenames.   The --dd option causes the shell to forget the remem-
              bered location of each _n_a_m_e.

              If the --tt option is supplied, hhaasshh prints the full pathname cor-
              responding to each _n_a_m_e.  If multiple _n_a_m_e  arguments  are  sup-
              plied  with  --tt,  hhaasshh  prints the _n_a_m_e before the corresponding
              hashed full pathname.  The --ll option displays output in a format
              that may be reused as input.

              If no arguments are given, or  if  only  --ll  is  supplied,  hhaasshh
              prints  information  about remembered commands.  The --tt, --dd, and
              --pp options (the options that act on the _n_a_m_e arguments) are  mu-
              tually exclusive.  Only one will be active.  If more than one is
              supplied,  --tt  has higher priority than --pp, and both have higher
              priority than --dd.

              The return status is zero unless a _n_a_m_e is not found or  an  in-
              valid option is supplied.

       hheellpp [--ddmmss] [_p_a_t_t_e_r_n]
              Display  helpful information about builtin commands.  If _p_a_t_t_e_r_n
              is specified, hheellpp gives detailed help on all commands  matching
              _p_a_t_t_e_r_n  as described below; otherwise it displays a list of all
              the builtins and shell compound commands.

              Options, if supplied, have the follow meanings:

              --dd     Display a short description of each _p_a_t_t_e_r_n
              --mm     Display the description of each _p_a_t_t_e_r_n in a manpage-like
                     format
              --ss     Display only a short usage synopsis for each _p_a_t_t_e_r_n

              If _p_a_t_t_e_r_n contains pattern  matching  characters  (see  PPaatttteerrnn
              MMaattcchhiinngg  above) it's treated as a shell pattern and hheellpp prints
              the description of each help topic matching _p_a_t_t_e_r_n.

              If not, and _p_a_t_t_e_r_n exactly matches the name of  a  help  topic,
              hheellpp  prints the description associated with that topic.  Other-
              wise, hheellpp performs prefix matching and prints the  descriptions
              of all matching help topics.

              The return status is 0 unless no command matches _p_a_t_t_e_r_n.

       hhiissttoorryy [[_n]]
       hhiissttoorryy --cc
       hhiissttoorryy --dd _o_f_f_s_e_t
       hhiissttoorryy --dd _s_t_a_r_t-_e_n_d
       hhiissttoorryy --aannrrww [_f_i_l_e_n_a_m_e]
       hhiissttoorryy --pp _a_r_g [_a_r_g ...]
       hhiissttoorryy --ss _a_r_g [_a_r_g ...]
              With  no options, display the command history list with numbers.
              Entries prefixed with a ** have been modified.  An argument of  _n
              lists  only the last _n entries.  If the shell variable HHIISSTTTTIIMMEE--
              FFOORRMMAATT is set and not null, it is used as a  format  string  for
              _s_t_r_f_t_i_m_e(3)  to display the time stamp associated with each dis-
              played history entry.  If hhiissttoorryy uses HHIISSTTTTIIMMEEFFOORRMMAATT,  it  does
              not  print an intervening space between the formatted time stamp
              and the history entry.

              If _f_i_l_e_n_a_m_e is supplied, hhiissttoorryy uses it as the name of the his-
              tory file; if not, it uses the value of HHIISSTTFFIILLEE.   If  _f_i_l_e_n_a_m_e
              is  not  supplied and HHIISSTTFFIILLEE is unset or null, the --aa,, --nn,, --rr,,
              and --ww options have no effect.

              Options, if supplied, have the following meanings:
              --cc     Clear the history list by deleting all the entries.  This
                     can be used with the other options to replace the history
                     list.
              --dd _o_f_f_s_e_t
                     Delete the history entry at position _o_f_f_s_e_t.   If  _o_f_f_s_e_t
                     is negative, it is interpreted as relative to one greater
                     than the last history position, so negative indices count
                     back  from  the  end  of  the history, and an index of -1
                     refers to the current hhiissttoorryy --dd command.
              --dd _s_t_a_r_t-_e_n_d
                     Delete the range of  history  entries  between  positions
                     _s_t_a_r_t  and  _e_n_d, inclusive.  Positive and negative values
                     for _s_t_a_r_t and _e_n_d are interpreted as described above.
              --aa     Append the history lines to the history file.  These  are
                     history  lines entered since the beginning of the current
                     bbaasshh session, but not already  appended  to  the  history
                     file.
              --nn     Read  the history lines not already read from the history
                     file and add them to the current history list.  These are
                     lines appended to the history file since the beginning of
                     the current bbaasshh session.
              --rr     Read the history file and append its contents to the cur-
                     rent history list.
              --ww     Write the current history list to the history file, over-
                     writing the history file.
              --pp     Perform history substitution on the  following  _a_r_g_s  and
                     display  the result on the standard output, without stor-
                     ing the results in the history list.  Each  _a_r_g  must  be
                     quoted to disable normal history expansion.
              --ss     Store  the  _a_r_g_s  in  the history list as a single entry.
                     The last command in the history list  is  removed  before
                     adding the _a_r_g_s.

              If  the  HHIISSTTTTIIMMEEFFOORRMMAATT variable is set, hhiissttoorryy writes the time
              stamp information associated with each history entry to the his-
              tory file, marked with the  history  comment  character  as  de-
              scribed  above.   When the history file is read, lines beginning
              with the history comment character  followed  immediately  by  a
              digit  are  interpreted  as timestamps for the following history
              entry.

              The return value is 0 unless an invalid option  is  encountered,
              an  error  occurs  while reading or writing the history file, an
              invalid _o_f_f_s_e_t or range is supplied as an argument to --dd, or the
              history expansion supplied as an argument to --pp fails.

       jjoobbss [--llnnpprrss] [ _j_o_b_s_p_e_c ... ]
       jjoobbss --xx _c_o_m_m_a_n_d [ _a_r_g_s ... ]
              The first form lists the active jobs.  The options have the fol-
              lowing meanings:
              --ll     List process IDs in addition to the normal information.
              --nn     Display information only about  jobs  that  have  changed
                     status since the user was last notified of their status.
              --pp     List  only  the  process  ID  of  the job's process group
                     leader.
              --rr     Display only running jobs.
              --ss     Display only stopped jobs.

              If _j_o_b_s_p_e_c is supplied, jjoobbss  restricts  output  to  information
              about that job.  The return status is 0 unless an invalid option
              is encountered or an invalid _j_o_b_s_p_e_c is supplied.

              If the --xx option is supplied, jjoobbss replaces any _j_o_b_s_p_e_c found in
              _c_o_m_m_a_n_d or _a_r_g_s with the corresponding process group ID, and ex-
              ecutes _c_o_m_m_a_n_d, passing it _a_r_g_s, returning its exit status.

       kkiillll [--ss _s_i_g_s_p_e_c | --nn _s_i_g_n_u_m | --_s_i_g_s_p_e_c] _i_d [ ... ]
       kkiillll --ll|--LL [_s_i_g_s_p_e_c | _e_x_i_t___s_t_a_t_u_s]
              Send  the signal specified by _s_i_g_s_p_e_c or _s_i_g_n_u_m to the processes
              named by each _i_d.  Each _i_d may be a job specification _j_o_b_s_p_e_c or
              a process ID _p_i_d.  _s_i_g_s_p_e_c is either a  case-insensitive  signal
              name  such as SSIIGGKKIILLLL (with or without the SSIIGG prefix) or a sig-
              nal number; _s_i_g_n_u_m is a signal number.  If _s_i_g_s_p_e_c is  not  sup-
              plied, then kkiillll sends SSIIGGTTEERRMM.

              The --ll option lists the signal names.  If any arguments are sup-
              plied when --ll is given, kkiillll lists the names of the signals cor-
              responding  to  the  arguments, and the return status is 0.  The
              _e_x_i_t___s_t_a_t_u_s argument to --ll is a number specifying either a  sig-
              nal  number or the exit status of a process terminated by a sig-
              nal; if it is supplied, kkiillll prints the name of the signal  that
              caused the process to terminate.  kkiillll assumes that process exit
              statuses are greater than 128; anything less than that is a sig-
              nal number.  The --LL option is equivalent to --ll.

              kkiillll  returns true if at least one signal was successfully sent,
              or false if an error occurs or an invalid option is encountered.

       lleett _a_r_g [_a_r_g ...]
              Each _a_r_g is evaluated as an arithmetic  expression  (see  AARRIITTHH--
              MMEETTIICC  EEVVAALLUUAATTIIOONN  in _b_a_s_h(1)).  If the last _a_r_g evaluates to 0,
              lleett returns 1; otherwise lleett returns 0.

       llooccaall [_o_p_t_i_o_n] [_n_a_m_e[=_v_a_l_u_e] ... | - ]
              For each argument, create a local variable named _n_a_m_e and assign
              it _v_a_l_u_e.  The _o_p_t_i_o_n can be any of the options accepted by  ddee--
              ccllaarree.   When  llooccaall  is  used  within a function, it causes the
              variable _n_a_m_e to have a visible scope restricted to  that  func-
              tion  and  its  children.   It is an error to use llooccaall when not
              within a function.

              If _n_a_m_e is -, it makes the set of shell  options  local  to  the
              function  in  which  llooccaall is invoked: any shell options changed
              using the sseett builtin inside the function after the call to  lloo--
              ccaall  are restored to their original values when the function re-
              turns.  The restore is performed as if a series of sseett  commands
              were  executed  to  restore the values that were in place before
              the function.

              With no operands, llooccaall writes a list of local variables to  the
              standard output.

              The  return status is 0 unless llooccaall is used outside a function,
              an invalid _n_a_m_e is supplied, or _n_a_m_e is a readonly variable.

       llooggoouutt [[_n]]
              Exit a login shell, returning a status of _n to the shell's  par-
              ent.

       mmaappffiillee [--dd _d_e_l_i_m] [--nn _c_o_u_n_t] [--OO _o_r_i_g_i_n] [--ss _c_o_u_n_t] [--tt] [--uu _f_d] [--CC
       _c_a_l_l_b_a_c_k] [--cc _q_u_a_n_t_u_m] [_a_r_r_a_y]
       rreeaaddaarrrraayy [--dd _d_e_l_i_m] [--nn _c_o_u_n_t] [--OO _o_r_i_g_i_n] [--ss _c_o_u_n_t] [--tt] [--uu _f_d] [--CC
       _c_a_l_l_b_a_c_k] [--cc _q_u_a_n_t_u_m] [_a_r_r_a_y]
              Read  lines  from the standard input, or from file descriptor _f_d
              if the --uu option is supplied, into the  indexed  array  variable
              _a_r_r_a_y.   The variable MMAAPPFFIILLEE is the default _a_r_r_a_y.  Options, if
              supplied, have the following meanings:
              --dd     Use the first character of _d_e_l_i_m to terminate each  input
                     line, rather than newline.  If _d_e_l_i_m is the empty string,
                     mmaappffiillee will terminate a line when it reads a NUL charac-
                     ter.
              --nn     Copy at most _c_o_u_n_t lines.  If _c_o_u_n_t is 0, copy all lines.
              --OO     Begin  assigning  to  _a_r_r_a_y at index _o_r_i_g_i_n.  The default
                     index is 0.
              --ss     Discard the first _c_o_u_n_t lines read.
              --tt     Remove a trailing _d_e_l_i_m (default newline) from each  line
                     read.
              --uu     Read  lines  from file descriptor _f_d instead of the stan-
                     dard input.
              --CC     Evaluate _c_a_l_l_b_a_c_k each time _q_u_a_n_t_u_m lines are read.   The
                     --cc option specifies _q_u_a_n_t_u_m.
              --cc     Specify  the  number  of  lines read between each call to
                     _c_a_l_l_b_a_c_k.

              If --CC is specified without --cc,  the  default  quantum  is  5000.
              When _c_a_l_l_b_a_c_k is evaluated, it is supplied the index of the next
              array element to be assigned and the line to be assigned to that
              element  as  additional  arguments.  _c_a_l_l_b_a_c_k is evaluated after
              the line is read but before the array element is assigned.

              If not supplied with an explicit origin, mmaappffiillee will clear  _a_r_-
              _r_a_y before assigning to it.

              mmaappffiillee returns zero unless an invalid option or option argument
              is  supplied,  _a_r_r_a_y  is invalid or unassignable, or if _a_r_r_a_y is
              not an indexed array.

       ppooppdd [-nn] [+_n] [-_n]
              Remove entries from the directory stack.  The elements are  num-
              bered  from 0 starting at the first directory listed by ddiirrss, so
              ppooppdd is equivalent to With no arguments, ppooppdd  removes  the  top
              directory  from the stack, and changes to the new top directory.
              Arguments, if supplied, have the following meanings:
              --nn     Suppress the normal change of directory when removing di-
                     rectories from the stack, only manipulate the stack.
              ++_n     Remove the _nth entry counting from the left of  the  list
                     shown  by  ddiirrss, starting with zero, from the stack.  For
                     example: removes the first directory, the second.
              --_n     Remove the _nth entry counting from the right of the  list
                     shown  by ddiirrss, starting with zero.  For example: removes
                     the last directory, the next to last.

              If the top element of the directory stack is modified,  and  the
              _-_n  option  was not supplied, ppooppdd uses the ccdd builtin to change
              to the directory at the top of the stack.  If the ccdd fails, ppooppdd
              returns a non-zero value.

              Otherwise, ppooppdd returns false if an invalid option is  supplied,
              the  directory stack is empty, or _n specifies a non-existent di-
              rectory stack entry.

              If the ppooppdd command is successful, bbaasshh runs ddiirrss  to  show  the
              final  contents of the directory stack, and the return status is
              0.

       pprriinnttff [--vv _v_a_r] _f_o_r_m_a_t [_a_r_g_u_m_e_n_t_s]
              Write the formatted _a_r_g_u_m_e_n_t_s to the standard output  under  the
              control  of the _f_o_r_m_a_t.  The --vv option assigns the output to the
              variable _v_a_r rather than printing it to the standard output.

              The _f_o_r_m_a_t is a character string which contains three  types  of
              objects:  plain  characters, which are simply copied to standard
              output, character escape  sequences,  which  are  converted  and
              copied  to  the standard output, and format specifications, each
              of which causes printing of the next  successive  _a_r_g_u_m_e_n_t.   In
              addition  to  the  standard  _p_r_i_n_t_f(3)  format  characters ccCCssSS--
              nnddiioouuxxXXeeEEffFFggGGaaAA, pprriinnttff interprets the following additional for-
              mat specifiers:
              %%bb     causes pprriinnttff to expand backslash escape sequences in the
                     corresponding _a_r_g_u_m_e_n_t in the same way as eecchhoo --ee.
              %%qq     causes pprriinnttff to output the corresponding _a_r_g_u_m_e_n_t  in  a
                     format  that can be reused as shell input.  %%qq and %%QQ use
                     the $$ quoting style if any  characters  in  the  argument
                     string  require  it, and backslash quoting otherwise.  If
                     the format string uses the _p_r_i_n_t_f alternate  form,  these
                     two  formats  quote  the  argument  string  using  single
                     quotes.
              %%QQ     like %%qq, but applies any supplied precision to the  _a_r_g_u_-
                     _m_e_n_t before quoting it.
              %%((_d_a_t_e_f_m_t))TT
                     causes  pprriinnttff  to  output the date-time string resulting
                     from using _d_a_t_e_f_m_t as a format  string  for  _s_t_r_f_t_i_m_e(3).
                     The corresponding _a_r_g_u_m_e_n_t is an integer representing the
                     number of seconds since the epoch.  This format specifier
                     recognizes two special argument values: -1 represents the
                     current  time,  and  -2 represents the time the shell was
                     invoked.  If no argument is specified, conversion behaves
                     as if -1 had been supplied.  This is an exception to  the
                     usual pprriinnttff behavior.

              The %b, %q, and %T format specifiers all use the field width and
              precision arguments from the format specification and write that
              many  bytes from (or use that wide a field for) the expanded ar-
              gument, which usually contains more characters than  the  origi-
              nal.

              The %n format specifier accepts a corresponding argument that is
              treated as a shell variable name.

              The  %s  and  %c  format specifiers accept an l (long) modifier,
              which forces them to convert the argument string to a wide-char-
              acter string and apply any supplied field width and precision in
              terms of characters, not bytes.  The %S and %C format specifiers
              are equivalent to %ls and %lc, respectively.

              Arguments to non-string format specifiers are treated as C  con-
              stants, except that a leading plus or minus sign is allowed, and
              if  the leading character is a single or double quote, the value
              is the numeric value of the following character, using the  cur-
              rent locale.

              The  _f_o_r_m_a_t  is  reused as necessary to consume all of the _a_r_g_u_-
              _m_e_n_t_s.  If the _f_o_r_m_a_t requires more _a_r_g_u_m_e_n_t_s than are supplied,
              the extra format specifications behave as if  a  zero  value  or
              null  string,  as  appropriate,  had  been supplied.  The return
              value is zero on success, non-zero if an invalid option is  sup-
              plied or a write or assignment error occurs.

       ppuusshhdd [--nn] [+_n] [-_n]
       ppuusshhdd [--nn] [_d_i_r]
              Add a directory to the top of the directory stack, or rotate the
              stack,  making  the new top of the stack the current working di-
              rectory.  With no arguments, ppuusshhdd exchanges the  top  two  ele-
              ments  of the directory stack.  Arguments, if supplied, have the
              following meanings:
              --nn     Suppress the normal change of directory when rotating  or
                     adding  directories  to  the  stack,  only manipulate the
                     stack.
              ++_n     Rotate the stack so that the _nth directory (counting from
                     the left of the list shown by ddiirrss, starting  with  zero)
                     is at the top.
              --_n     Rotates  the  stack  so  that the _nth directory (counting
                     from the right of the list shown by ddiirrss,  starting  with
                     zero) is at the top.
              _d_i_r    Adds _d_i_r to the directory stack at the top.

              After the stack has been modified, if the --nn option was not sup-
              plied,  ppuusshhdd  uses the ccdd builtin to change to the directory at
              the top of the stack.  If the ccdd fails, ppuusshhdd returns a non-zero
              value.

              Otherwise, if no arguments are supplied, ppuusshhdd returns zero  un-
              less  the directory stack is empty.  When rotating the directory
              stack, ppuusshhdd returns zero unless the directory stack is empty or
              _n specifies a non-existent directory stack element.

              If the ppuusshhdd command is successful, bbaasshh runs ddiirrss to  show  the
              final contents of the directory stack.

       ppwwdd [--LLPP]
              Print  the  absolute  pathname of the current working directory.
              The pathname printed contains no symbolic links if the --PP option
              is supplied or the --oo pphhyyssiiccaall option to the sseett builtin command
              is enabled.  If the --LL option is used, the pathname printed  may
              contain  symbolic links.  The return status is 0 unless an error
              occurs while reading the name of the current directory or an in-
              valid option is supplied.

       rreeaadd [--EEeerrss] [--aa _a_n_a_m_e] [--dd _d_e_l_i_m] [--ii _t_e_x_t] [--nn _n_c_h_a_r_s] [--NN _n_c_h_a_r_s]
       [--pp _p_r_o_m_p_t] [--tt _t_i_m_e_o_u_t] [--uu _f_d] [_n_a_m_e ...]
              Read one line from the standard input, or from the file descrip-
              tor _f_d supplied as an argument to the --uu option, split  it  into
              words  as described in _b_a_s_h (1) under WWoorrdd SSpplliittttiinngg, and assign
              the first word to the first _n_a_m_e, the second word to the  second
              _n_a_m_e,  and  so  on.  If there are more words than names, the re-
              maining words and their intervening delimiters are  assigned  to
              the  last  _n_a_m_e.   If  there are fewer words read from the input
              stream than names, the remaining names are assigned  empty  val-
              ues.   The  characters in the value of the IIFFSS variable are used
              to split the line into words using the same rules the shell uses
              for expansion (described in _b_a_s_h (1) under WWoorrdd SSpplliittttiinngg).  The
              backslash character (\\) removes any special meaning for the next
              character read and is used for line continuation.

              Options, if supplied, have the following meanings:
              --aa _a_n_a_m_e
                     The words are assigned to sequential indices of the array
                     variable _a_n_a_m_e, starting at 0.  _a_n_a_m_e is unset before any
                     new values are assigned.  Other _n_a_m_e  arguments  are  ig-
                     nored.
              --dd _d_e_l_i_m
                     The  first  character of _d_e_l_i_m terminates the input line,
                     rather than newline.  If _d_e_l_i_m is the empty string,  rreeaadd
                     will terminate a line when it reads a NUL character.
              --ee     If  the  standard  input  is coming from a terminal, rreeaadd
                     uses rreeaaddlliinnee (see RREEAADDLLIINNEE in  _b_a_s_h(1))  to  obtain  the
                     line.   RReeaaddlliinnee  uses  the  current (or default, if line
                     editing was not previously active) editing settings,  but
                     uses rreeaaddlliinnee's default filename completion.
              --EE     If  the  standard  input  is coming from a terminal, rreeaadd
                     uses rreeaaddlliinnee (see RREEAADDLLIINNEE in  _b_a_s_h(1))  to  obtain  the
                     line.   RReeaaddlliinnee  uses  the  current (or default, if line
                     editing was not previously active) editing settings,  but
                     uses  bash's  default  completion, including programmable
                     completion.
              --ii _t_e_x_t
                     If rreeaaddlliinnee is being used to read the line,  rreeaadd  places
                     _t_e_x_t into the editing buffer before editing begins.
              --nn _n_c_h_a_r_s
                     rreeaadd  returns after reading _n_c_h_a_r_s characters rather than
                     waiting for a complete line of input, unless  it  encoun-
                     ters  EOF or rreeaadd times out, but honors a delimiter if it
                     reads fewer than _n_c_h_a_r_s characters before the delimiter.
              --NN _n_c_h_a_r_s
                     rreeaadd returns  after  reading  exactly  _n_c_h_a_r_s  characters
                     rather  than waiting for a complete line of input, unless
                     it encounters EOF or rreeaadd times out.  Any delimiter char-
                     acters in the input are not treated specially and do  not
                     cause rreeaadd to return until it has read _n_c_h_a_r_s characters.
                     The result is not split on the characters in IIFFSS; the in-
                     tent is that the variable is assigned exactly the charac-
                     ters  read  (with  the exception of backslash; see the --rr
                     option below).
              --pp _p_r_o_m_p_t
                     Display _p_r_o_m_p_t on standard error, without a trailing new-
                     line, before attempting to read any input,  but  only  if
                     input is coming from a terminal.
              --rr     Backslash does not act as an escape character.  The back-
                     slash  is considered to be part of the line.  In particu-
                     lar, a backslash-newline pair may not then be used  as  a
                     line continuation.
              --ss     Silent mode.  If input is coming from a terminal, charac-
                     ters are not echoed.
              --tt _t_i_m_e_o_u_t
                     Cause  rreeaadd to time out and return failure if it does not
                     read a complete line of input (or a specified  number  of
                     characters)  within  _t_i_m_e_o_u_t  seconds.   _t_i_m_e_o_u_t may be a
                     decimal number with a fractional  portion  following  the
                     decimal  point.  This option is only effective if rreeaadd is
                     reading input from a terminal,  pipe,  or  other  special
                     file;  it  has no effect when reading from regular files.
                     If rreeaadd times out, it saves any partial input  read  into
                     the  specified  variable  _n_a_m_e,  and  the  exit status is
                     greater than 128.  If _t_i_m_e_o_u_t is 0, rreeaadd returns  immedi-
                     ately,  without  trying  to read any data.  In this case,
                     the exit status is 0 if input is available on the  speci-
                     fied  file  descriptor, or the read will return EOF, non-
                     zero otherwise.
              --uu _f_d  Read input from file descriptor _f_d instead of  the  stan-
                     dard input.

              Other  than  the  case where _d_e_l_i_m is the empty string, rreeaadd ig-
              nores any NUL characters in the input.

              If no _n_a_m_e_s are supplied, rreeaadd assigns the  line  read,  without
              the  ending  delimiter but otherwise unmodified, to the variable
              RREEPPLLYY.

              The exit status is zero, unless end-of-file is encountered, rreeaadd
              times out (in which case the status  is  greater  than  128),  a
              variable assignment error (such as assigning to a readonly vari-
              able)  occurs,  or an invalid file descriptor is supplied as the
              argument to --uu.

       rreeaaddoonnllyy [--aaAAff] [--pp] [_n_a_m_e[=_w_o_r_d] ...]
              The given _n_a_m_e_s are marked readonly; the values of  these  _n_a_m_e_s
              may not be changed by subsequent assignment or unset.  If the --ff
              option  is  supplied, each _n_a_m_e refers to a shell function.  The
              --aa option restricts the variables to indexed arrays; the --AA  op-
              tion restricts the variables to associative arrays.  If both op-
              tions  are  supplied, --AA takes precedence.  If no _n_a_m_e arguments
              are supplied, or if the --pp option is supplied, print a  list  of
              all  readonly  names.  The other options may be used to restrict
              the output to a subset of the set of readonly names.  The --pp op-
              tion displays output in a format that may be reused as input.

              rreeaaddoonnllyy allows the value of a variable to be set  at  the  same
              time the readonly attribute is changed by following the variable
              name  with  =_v_a_l_u_e.   This  sets the value of the variable is to
              _v_a_l_u_e while modifying the readonly attribute.

              The return status is 0 unless an invalid option is  encountered,
              one  of  the  _n_a_m_e_s is not a valid shell variable name, or --ff is
              supplied with a _n_a_m_e that is not a function.

       rreettuurrnn [_n]
              Stop executing a shell function or sourced file and  return  the
              value specified by _n to its caller.  If _n is omitted, the return
              status  is that of the last command executed.  If rreettuurrnn is exe-
              cuted by a trap handler, the last command used to determine  the
              status is the last command executed before the trap handler.  If
              rreettuurrnn is executed during a DDEEBBUUGG trap, the last command used to
              determine  the  status  is the last command executed by the trap
              handler before rreettuurrnn was invoked.

              When rreettuurrnn is used to terminate execution of a script being ex-
              ecuted by the ..  (ssoouurrccee) command, it causes the shell  to  stop
              executing  that script and return either _n or the exit status of
              the last command executed within the script as the  exit  status
              of  the script.  If _n is supplied, the return value is its least
              significant 8 bits.

              Any command associated with the RREETTUURRNN trap is  executed  before
              execution resumes after the function or script.

              The  return  status  is non-zero if rreettuurrnn is supplied a non-nu-
              meric argument, or is used outside a function and not during ex-
              ecution of a script by .. or ssoouurrccee.

       sseett [--aabbeeffhhkkmmnnppttuuvvxxBBCCEEHHPPTT] [--oo _o_p_t_i_o_n_-_n_a_m_e] [----] [--] [_a_r_g ...]
       sseett [++aabbeeffhhkkmmnnppttuuvvxxBBCCEEHHPPTT] [++oo _o_p_t_i_o_n_-_n_a_m_e] [----] [--] [_a_r_g ...]
       sseett --oo
       sseett ++oo Without options, display the name and value of each shell  vari-
              able  in a format that can be reused as input for setting or re-
              setting the currently-set variables.  Read-only variables cannot
              be reset.  In posix mode, only shell variables are listed.   The
              output  is sorted according to the current locale.  When options
              are specified, they set or unset shell  attributes.   Any  argu-
              ments  remaining  after  option processing are treated as values
              for the positional parameters and are assigned, in order, to $$11,
              $$22, ..., $$_n.  Options, if specified, have  the  following  mean-
              ings:
              --aa      Each variable or function that is created or modified is
                      given  the export attribute and marked for export to the
                      environment of subsequent commands.
              --bb      Report the status of terminated background jobs  immedi-
                      ately, rather than before the next primary prompt or af-
                      ter  a foreground command terminates.  This is effective
                      only when job control is enabled.
              --ee      Exit immediately if a _p_i_p_e_l_i_n_e (which may consist  of  a
                      single  _s_i_m_p_l_e  _c_o_m_m_a_n_d),  a _l_i_s_t, or a _c_o_m_p_o_u_n_d _c_o_m_m_a_n_d
                      (see SSHHEELLLL GGRRAAMMMMAARR in _b_a_s_h(1)), exits  with  a  non-zero
                      status.   The  shell  does  not exit if the command that
                      fails is part of the command list immediately  following
                      a wwhhiillee or uunnttiill reserved word, part of the test follow-
                      ing  the  iiff or eelliiff reserved words, part of any command
                      executed in a &&&& or |||| list except the command following
                      the final &&&& or ||||, any command in a  pipeline  but  the
                      last  (subject  to  the  state of the ppiippeeffaaiill shell op-
                      tion), or if the command's return  value  is  being  in-
                      verted  with !!.  If a compound command other than a sub-
                      shell returns a non-zero status because a command failed
                      while --ee was being ignored, the shell does not exit.   A
                      trap on EERRRR, if set, is executed before the shell exits.
                      This  option  applies  to the shell environment and each
                      subshell environment separately (see  CCOOMMMMAANNDD  EEXXEECCUUTTIIOONN
                      EENNVVIIRROONNMMEENNTT in _b_a_s_h(1)), and may cause subshells to exit
                      before executing all the commands in the subshell.

                      If  a  compound  command or shell function executes in a
                      context where --ee is being ignored, none of the  commands
                      executed  within  the  compound command or function body
                      will be affected by the --ee setting, even if  --ee  is  set
                      and  a  command returns a failure status.  If a compound
                      command or shell function sets --ee while executing  in  a
                      context  where --ee is ignored, that setting will not have
                      any effect until the compound  command  or  the  command
                      containing the function call completes.
              --ff      Disable pathname expansion.
              --hh      Remember  the location of commands as they are looked up
                      for execution.  This is enabled by default.
              --kk      All arguments in the form of assignment  statements  are
                      placed  in the environment for a command, not just those
                      that precede the command name.
              --mm      Monitor mode.  Job control is enabled.  This  option  is
                      on  by  default  for  interactive shells on systems that
                      support it (see JJOOBB CCOONNTTRROOLL in _b_a_s_h(1)).  All  processes
                      run  in a separate process group.  When a background job
                      completes, the shell prints a line containing  its  exit
                      status.
              --nn      Read commands but do not execute them.  This may be used
                      to  check a shell script for syntax errors.  This is ig-
                      nored by interactive shells.
              --oo _o_p_t_i_o_n_-_n_a_m_e
                      The _o_p_t_i_o_n_-_n_a_m_e can be one of the following:
                      aalllleexxppoorrtt
                              Same as --aa.
                      bbrraacceeeexxppaanndd
                              Same as --BB.
                      eemmaaccss   Use an emacs-style command line  editing  inter-
                              face.  This is enabled by default when the shell
                              is interactive, unless the shell is started with
                              the  ----nnooeeddiittiinngg  option.  This also affects the
                              editing interface used for rreeaadd --ee.
                      eerrrreexxiitt Same as --ee.
                      eerrrrttrraaccee
                              Same as --EE.
                      ffuunnccttrraaccee
                              Same as --TT.
                      hhaasshhaallll Same as --hh.
                      hhiisstteexxppaanndd
                              Same as --HH.
                      hhiissttoorryy Enable command history, as described in  _b_a_s_h(1)
                              under  HHIISSTTOORRYY.  This option is on by default in
                              interactive shells.
                      iiggnnoorreeeeooff
                              The effect is as if the shell command  had  been
                              executed (see SShheellll VVaarriiaabblleess in _b_a_s_h(1)).
                      kkeeyywwoorrdd Same as --kk.
                      mmoonniittoorr Same as --mm.
                      nnoocclloobbbbeerr
                              Same as --CC.
                      nnooeexxeecc  Same as --nn.
                      nnoogglloobb  Same as --ff.
                      nnoolloogg   Currently ignored.
                      nnoottiiffyy  Same as --bb.
                      nnoouunnsseett Same as --uu.
                      oonneeccmmdd  Same as --tt.
                      pphhyyssiiccaall
                              Same as --PP.
                      ppiippeeffaaiill
                              If  set,  the  return value of a pipeline is the
                              value of the last (rightmost)  command  to  exit
                              with  a non-zero status, or zero if all commands
                              in the pipeline exit successfully.  This  option
                              is disabled by default.
                      ppoossiixx   Enable  posix  mode; change the behavior of bbaasshh
                              where the default  operation  differs  from  the
                              POSIX  standard  to match the standard.  See SSEEEE
                              AALLSSOO in _b_a_s_h(1) for a reference  to  a  document
                              that  details  how posix mode affects bash's be-
                              havior.
                      pprriivviilleeggeedd
                              Same as --pp.
                      vveerrbboossee Same as --vv.
                      vvii      Use a vi-style command line  editing  interface.
                              This also affects the editing interface used for
                              rreeaadd --ee.
                      xxttrraaccee  Same as --xx.
                      If  --oo  is  supplied with no _o_p_t_i_o_n_-_n_a_m_e, sseett prints the
                      current shell option settings.  If ++oo is  supplied  with
                      no  _o_p_t_i_o_n_-_n_a_m_e,  sseett prints a series of sseett commands to
                      recreate the current option  settings  on  the  standard
                      output.
              --pp      Turn  on  _p_r_i_v_i_l_e_g_e_d mode.  In this mode, the shell does
                      not read the $$EENNVV and $$BBAASSHH__EENNVV files,  shell  functions
                      are  not  inherited  from the environment, and the SSHHEELL--
                      LLOOPPTTSS, BBAASSHHOOPPTTSS, CCDDPPAATTHH, and  GGLLOOBBIIGGNNOORREE  variables,  if
                      they  appear  in  the  environment, are ignored.  If the
                      shell is started with the effective user (group) id  not
                      equal  to the real user (group) id, and the --pp option is
                      not supplied, these actions are taken and the  effective
                      user id is set to the real user id.  If the --pp option is
                      supplied at startup, the effective user id is not reset.
                      Turning  this  option  off causes the effective user and
                      group ids to be set to the real user and group ids.
              --rr      Enable restricted shell mode.  This option cannot be un-
                      set once it has been set.
              --tt      Exit after reading and executing one command.
              --uu      Treat unset variables and parameters other than the spe-
                      cial parameters and or array variables subscripted  with
                      or  as an error when performing parameter expansion.  If
                      expansion is attempted on an unset variable  or  parame-
                      ter,  the shell prints an error message, and, if not in-
                      teractive, exits with a non-zero status.
              --vv      Print shell input lines as they are read.
              --xx      After expanding each _s_i_m_p_l_e _c_o_m_m_a_n_d, ffoorr  command,  ccaassee
                      command, sseelleecctt command, or arithmetic ffoorr command, dis-
                      play  the expanded value of PPSS44, followed by the command
                      and its expanded arguments or associated word  list,  to
                      the standard error.
              --BB      The  shell performs brace expansion (see BBrraaccee EExxppaannssiioonn
                      in _b_a_s_h(1)).  This is on by default.
              --CC      If set, bbaasshh does not overwrite an  existing  file  with
                      the  >>,  >>&&,  and  <<>>  redirection operators.  Using the
                      redirection operator >>|| instead of >> will override  this
                      and force the creation of an output file.
              --EE      If set, any trap on EERRRR is inherited by shell functions,
                      command  substitutions,  and commands executed in a sub-
                      shell environment.  The EERRRR trap is normally not  inher-
                      ited in such cases.
              --HH      Enable !!  style history substitution.  This option is on
                      by default when the shell is interactive.
              --PP      If  set,  the shell does not resolve symbolic links when
                      executing commands such as ccdd that  change  the  current
                      working  directory.   It  uses  the  physical  directory
                      structure instead.  By default, bbaasshh follows the logical
                      chain of  directories  when  performing  commands  which
                      change the current directory.
              --TT      If  set,  any traps on DDEEBBUUGG and RREETTUURRNN are inherited by
                      shell functions, command substitutions, and commands ex-
                      ecuted in a subshell environment.  The DDEEBBUUGG and  RREETTUURRNN
                      traps are normally not inherited in such cases.
              ----      If no arguments follow this option, unset the positional
                      parameters.  Otherwise, set the positional parameters to
                      the _a_r_gs, even if some of them begin with a --.
              --       Signal the end of options, and assign all remaining _a_r_gs
                      to the positional parameters.  The --xx and --vv options are
                      turned  off.  If there are no _a_r_gs, the positional para-
                      meters remain unchanged.

              The options are off by default unless otherwise noted.  Using  +
              rather  than  -  causes these options to be turned off.  The op-
              tions can also be specified as arguments to an invocation of the
              shell.  The current set of options may be found in $$--.  The  re-
              turn  status  is always zero unless an invalid option is encoun-
              tered.

       sshhiifftt [_n]
              Rename positional parameters from _n+1 ... to $$11 ........  Parameters
              represented by the numbers $$## down to $$##-_n+1 are unset.  _n  must
              be  a  non-negative number less than or equal to $$##.  If _n is 0,
              no parameters are changed.  If _n is not given, it is assumed  to
              be  1.   If  _n is greater than $$##, the positional parameters are
              not changed.  The return status is greater than  zero  if  _n  is
              greater than $$## or less than zero; otherwise 0.

       sshhoopptt [--ppqqssuu] [--oo] [_o_p_t_n_a_m_e ...]
              Toggle  the values of settings controlling optional shell behav-
              ior.  The settings can be either those listed below, or, if  the
              --oo option is used, those available with the --oo option to the sseett
              builtin command.

              With  no  options,  or with the --pp option, display a list of all
              settable options, with an indication of whether or not  each  is
              set;  if  any _o_p_t_n_a_m_e_s are supplied, the output is restricted to
              those options.  The --pp option displays output in a form that may
              be reused as input.

              Other options have the following meanings:
              --ss     Enable (set) each _o_p_t_n_a_m_e.
              --uu     Disable (unset) each _o_p_t_n_a_m_e.
              --qq     Suppresses normal output (quiet mode); the return  status
                     indicates whether the _o_p_t_n_a_m_e is set or unset.  If multi-
                     ple  _o_p_t_n_a_m_e  arguments  are supplied with --qq, the return
                     status is zero if all _o_p_t_n_a_m_e_s are enabled; non-zero oth-
                     erwise.
              --oo     Restricts the values of _o_p_t_n_a_m_e to be those  defined  for
                     the --oo option to the sseett builtin.

              If  either  --ss  or  --uu  is used with no _o_p_t_n_a_m_e arguments, sshhoopptt
              shows only those options which are set or  unset,  respectively.
              Unless  otherwise  noted, the sshhoopptt options are disabled (unset)
              by default.

              The return status when listing options is zero if  all  _o_p_t_n_a_m_e_s
              are  enabled, non-zero otherwise.  When setting or unsetting op-
              tions, the return status is zero unless  an  _o_p_t_n_a_m_e  is  not  a
              valid shell option.

              The list of sshhoopptt options is:

              aarrrraayy__eexxppaanndd__oonnccee
                      If  set, the shell suppresses multiple evaluation of as-
                      sociative and indexed array subscripts during arithmetic
                      expression evaluation, while executing builtins that can
                      perform  variable  assignments,  and   while   executing
                      builtins that perform array dereferencing.
              aassssoocc__eexxppaanndd__oonnccee
                      Deprecated; a synonym for aarrrraayy__eexxppaanndd__oonnccee.
              aauuttooccdd  If  set,  a command name that is the name of a directory
                      is executed as if it were the argument to  the  ccdd  com-
                      mand.  This option is only used by interactive shells.
              bbaasshh__ssoouurrccee__ffuullllppaatthh
                      If  set,  filenames added to the BBAASSHH__SSOOUURRCCEE array vari-
                      able are converted to full pathnames  (see  SShheellll  VVaarrii--
                      aabblleess above).
              ccddaabbllee__vvaarrss
                      If  set,  an  argument to the ccdd builtin command that is
                      not a directory is assumed to be the name of a  variable
                      whose value is the directory to change to.
              ccddssppeellll If  set, the ccdd command attempts to correct minor errors
                      in the spelling of a directory component.  Minor  errors
                      include  transposed characters, a missing character, and
                      one extra character.  If ccdd corrects the directory name,
                      it prints the corrected filename, and the  command  pro-
                      ceeds.  This option is only used by interactive shells.
              cchheecckkhhaasshh
                      If set, bbaasshh checks that a command found in the hash ta-
                      ble  exists  before  trying  to execute it.  If a hashed
                      command no longer exists, bbaasshh performs  a  normal  path
                      search.
              cchheecckkjjoobbss
                      If set, bbaasshh lists the status of any stopped and running
                      jobs  before  exiting an interactive shell.  If any jobs
                      are running, bbaasshh defers the exit until a second exit is
                      attempted without an intervening command (see  JJOOBB  CCOONN--
                      TTRROOLL in _b_a_s_h(1)).  The shell always postpones exiting if
                      any jobs are stopped.
              cchheecckkwwiinnssiizzee
                      If  set, bbaasshh checks the window size after each external
                      (non-builtin) command and,  if  necessary,  updates  the
                      values  of  LLIINNEESS and CCOOLLUUMMNNSS, using the file descriptor
                      associated with the standard error if it is a  terminal.
                      This option is enabled by default.
              ccmmddhhiisstt If  set,  bbaasshh attempts to save all lines of a multiple-
                      line command in the same  history  entry.   This  allows
                      easy  re-editing of multi-line commands.  This option is
                      enabled by default, but only has an  effect  if  command
                      history  is  enabled, as described in _b_a_s_h(1) under HHIISS--
                      TTOORRYY.
              ccoommppaatt3311
              ccoommppaatt3322
              ccoommppaatt4400
              ccoommppaatt4411
              ccoommppaatt4422
              ccoommppaatt4433
              ccoommppaatt4444
                      These control aspects of the shell's compatibility  mode
                      (see SSHHEELLLL CCOOMMPPAATTIIBBIILLIITTYY MMOODDEE in _b_a_s_h(1)).
              ccoommpplleettee__ffuullllqquuoottee
                      If  set,  bbaasshh  quotes all shell metacharacters in file-
                      names and directory names  when  performing  completion.
                      If not set, bbaasshh removes metacharacters such as the dol-
                      lar  sign from the set of characters that will be quoted
                      in completed filenames when these metacharacters  appear
                      in  shell  variable references in words to be completed.
                      This means that dollar signs in variable names that  ex-
                      pand  to  directories  will  not be quoted; however, any
                      dollar signs appearing in filenames will not be  quoted,
                      either.   This  is  active only when bash is using back-
                      slashes to quote completed filenames.  This variable  is
                      set  by  default,  which is the default bash behavior in
                      versions through 4.2.
              ddiirreexxppaanndd
                      If set, bbaasshh replaces directory names with  the  results
                      of  word  expansion when performing filename completion.
                      This  changes  the  contents  of  the  rreeaaddlliinnee  editing
                      buffer.   If not set, bbaasshh attempts to preserve what the
                      user typed.
              ddiirrssppeellll
                      If set, bbaasshh attempts spelling correction  on  directory
                      names  during word completion if the directory name ini-
                      tially supplied does not exist.
              ddoottgglloobb If set, bbaasshh includes filenames beginning with a in  the
                      results  of  pathname expansion.  The filenames _. and _._.
                      must always be matched explicitly, even  if  ddoottgglloobb  is
                      set.
              eexxeeccffaaiill
                      If set, a non-interactive shell will not exit if it can-
                      not  execute  the  file  specified as an argument to the
                      eexxeecc builtin.  An interactive shell  does  not  exit  if
                      eexxeecc fails.
              eexxppaanndd__aalliiaasseess
                      If set, aliases are expanded as described in _b_a_s_h(1) un-
                      der  AALLIIAASSEESS.  This option is enabled by default for in-
                      teractive shells.
              eexxttddeebbuugg
                      If set at shell invocation, or in a shell startup  file,
                      arrange to execute the debugger profile before the shell
                      starts,  identical to the ----ddeebbuuggggeerr option.  If set af-
                      ter invocation, behavior intended for use  by  debuggers
                      is enabled:
                      11..     The --FF option to the ddeeccllaarree builtin displays the
                             source file name and line number corresponding to
                             each function name supplied as an argument.
                      22..     If  the  command  run by the DDEEBBUUGG trap returns a
                             non-zero value, the next command is  skipped  and
                             not executed.
                      33..     If  the  command  run by the DDEEBBUUGG trap returns a
                             value of 2, and the shell is executing in a  sub-
                             routine  (a shell function or a shell script exe-
                             cuted by the .. or  ssoouurrccee  builtins),  the  shell
                             simulates a call to rreettuurrnn.
                      44..     BBAASSHH__AARRGGCC  and BBAASSHH__AARRGGVV are updated as described
                             in their descriptions in _b_a_s_h(1)).
                      55..     Function tracing is  enabled:  command  substitu-
                             tion, shell functions, and subshells invoked with
                             (( _c_o_m_m_a_n_d )) inherit the DDEEBBUUGG and RREETTUURRNN traps.
                      66..     Error  tracing  is enabled: command substitution,
                             shell functions, and  subshells  invoked  with  ((
                             _c_o_m_m_a_n_d )) inherit the EERRRR trap.
              eexxttgglloobb If  set,  enable  the extended pattern matching features
                      described in _b_a_s_h(1) under PPaatthhnnaammee EExxppaannssiioonn.
              eexxttqquuoottee
                      If set, $$_s_t_r_i_n_g and $$_s_t_r_i_n_g quoting is performed  within
                      $${{_p_a_r_a_m_e_t_e_r}} expansions enclosed in double quotes.  This
                      option is enabled by default.
              ffaaiillgglloobb
                      If  set,  patterns  which fail to match filenames during
                      pathname expansion result in an expansion error.
              ffoorrccee__ffiiggnnoorree
                      If set, the suffixes  specified  by  the  FFIIGGNNOORREE  shell
                      variable  cause words to be ignored when performing word
                      completion even if the ignored words are the only possi-
                      ble completions.  See SShheellll VVaarriiaabblleess in _b_a_s_h(1)  for  a
                      description  of  FFIIGGNNOORREE.  This option is enabled by de-
                      fault.
              gglloobbaasscciiiirraannggeess
                      If set,  range  expressions  used  in  pattern  matching
                      bracket  expressions  (see  PPaatttteerrnn MMaattcchhiinngg in _b_a_s_h(1))
                      behave as if in the traditional C locale when performing
                      comparisons.  That is, pattern matching  does  not  take
                      the current locale's collating sequence into account, so
                      bb  will  not collate between AA and BB, and upper-case and
                      lower-case ASCII characters will collate together.
              gglloobbsskkiippddoottss
                      If set, pathname expansion will never  match  the  file-
                      names  _.  and  _._. even if the pattern begins with a This
                      option is enabled by default.
              gglloobbssttaarr
                      If set, the pattern **** used in a pathname expansion con-
                      text will match all files and zero or  more  directories
                      and  subdirectories.  If the pattern is followed by a //,
                      only directories and subdirectories match.
              ggnnuu__eerrrrffmmtt
                      If set, shell error messages are written in the standard
                      GNU error message format.
              hhiissttaappppeenndd
                      If set, the history list is appended to the  file  named
                      by the value of the HHIISSTTFFIILLEE variable when the shell ex-
                      its, rather than overwriting the file.
              hhiissttrreeeeddiitt
                      If  set,  and  rreeaaddlliinnee is being used, the user is given
                      the opportunity to re-edit a  failed  history  substitu-
                      tion.
              hhiissttvveerriiffyy
                      If  set, and rreeaaddlliinnee is being used, the results of his-
                      tory substitution are  not  immediately  passed  to  the
                      shell  parser.   Instead,  the  resulting line is loaded
                      into the rreeaaddlliinnee editing buffer, allowing further modi-
                      fication.
              hhoossttccoommpplleettee
                      If set, and rreeaaddlliinnee is being used, bbaasshh will attempt to
                      perform hostname completion when a word containing  a  @@
                      is  being  completed  (see  CCoommpplleettiinngg under RREEAADDLLIINNEE in
                      _b_a_s_h(1)).  This is enabled by default.
              hhuuppoonneexxiitt
                      If set, bbaasshh will send SSIIGGHHUUPP to all jobs when an inter-
                      active login shell exits.
              iinnhheerriitt__eerrrreexxiitt
                      If set, command substitution inherits the value  of  the
                      eerrrreexxiitt  option, instead of unsetting it in the subshell
                      environment.  This option is enabled when posix mode  is
                      enabled.
              iinntteerraaccttiivvee__ccoommmmeennttss
                      In  an interactive shell, a word beginning with ## causes
                      that word and all remaining characters on that  line  to
                      be  ignored, as in a non-interactive shell (see CCOOMMMMEENNTTSS
                      in _b_a_s_h(1)).  This option is enabled by default.
              llaassttppiippee
                      If set, and job control is not active,  the  shell  runs
                      the last command of a pipeline not executed in the back-
                      ground in the current shell environment.
              lliitthhiisstt If  set,  and  the ccmmddhhiisstt option is enabled, multi-line
                      commands are saved to the history with embedded newlines
                      rather than using semicolon separators where possible.
              llooccaallvvaarr__iinnhheerriitt
                      If set, local variables inherit the value and attributes
                      of a variable of the same name that exists at a previous
                      scope before any new value is assigned.  The nameref at-
                      tribute is not inherited.
              llooccaallvvaarr__uunnsseett
                      If set, calling uunnsseett on  local  variables  in  previous
                      function  scopes  marks  them so subsequent lookups find
                      them unset until that function returns.  This is identi-
                      cal to the behavior of unsetting local variables at  the
                      current function scope.
              llooggiinn__sshheellll
                      The  shell  sets this option if it is started as a login
                      shell (see IINNVVOOCCAATTIIOONN in _b_a_s_h(1)).  The value may not be
                      changed.
              mmaaiillwwaarrnn
                      If set, and a file that bbaasshh is checking  for  mail  has
                      been  accessed  since the last time it was checked, bbaasshh
                      displays the message
              nnoo__eemmppttyy__ccmmdd__ccoommpplleettiioonn
                      If set, and rreeaaddlliinnee is being used, bbaasshh does not search
                      PPAATTHH for possible completions  when  completion  is  at-
                      tempted on an empty line.
              nnooccaasseegglloobb
                      If  set,  bbaasshh  matches  filenames in a case-insensitive
                      fashion when performing pathname expansion (see PPaatthhnnaammee
                      EExxppaannssiioonn in _b_a_s_h(1)).
              nnooccaasseemmaattcchh
                      If set, bbaasshh  matches  patterns  in  a  case-insensitive
                      fashion when performing matching while executing ccaassee or
                      [[[[ conditional commands, when performing pattern substi-
                      tution  word expansions, or when filtering possible com-
                      pletions as part of programmable completion.
              nnooeexxppaanndd__ttrraannssllaattiioonn
                      If set, bbaasshh encloses the  translated  results  of  $$...
                      quoting  in  single quotes instead of double quotes.  If
                      the string is not translated, this has no effect.
              nnuullllgglloobb
                      If set, pathname expansion patterns which match no files
                      (see PPaatthhnnaammee EExxppaannssiioonn in _b_a_s_h(1))  expand  to  nothing
                      and are removed, rather than expanding to themselves.
              ppaattssuubb__rreeppllaacceemmeenntt
                      If set, bbaasshh expands occurrences of && in the replacement
                      string  of  pattern  substitution to the text matched by
                      the pattern, as described under PPaarraammeetteerr  EExxppaannssiioonn  in
                      _b_a_s_h(1).  This option is enabled by default.
              pprrooggccoommpp
                      If  set,  enable  the programmable completion facilities
                      (see PPrrooggrraammmmaabbllee CCoommpplleettiioonn in _b_a_s_h(1)).   This  option
                      is enabled by default.
              pprrooggccoommpp__aalliiaass
                      If  set,  and  programmable  completion is enabled, bbaasshh
                      treats a command name that doesn't have any  completions
                      as a possible alias and attempts alias expansion.  If it
                      has  an alias, bbaasshh attempts programmable completion us-
                      ing the command word resulting from the expanded alias.
              pprroommppttvvaarrss
                      If set, prompt strings undergo parameter expansion, com-
                      mand substitution, arithmetic expansion, and  quote  re-
                      moval  after being expanded as described in PPRROOMMPPTTIINNGG in
                      _b_a_s_h(1).  This option is enabled by default.
              rreessttrriicctteedd__sshheellll
                      The shell sets this option  if  it  is  started  in  re-
                      stricted  mode  (see  RREESSTTRRIICCTTEEDD SSHHEELLLL in _b_a_s_h(1)).  The
                      value may not be changed.  This is not  reset  when  the
                      startup  files  are executed, allowing the startup files
                      to discover whether or not a shell is restricted.
              sshhiifftt__vveerrbboossee
                      If set, the sshhiifftt builtin prints an error  message  when
                      the shift count exceeds the number of positional parame-
                      ters.
              ssoouurrcceeppaatthh
                      If set, the .. (ssoouurrccee) builtin uses the value of PPAATTHH to
                      find  the  directory  containing the file supplied as an
                      argument when the --pp option is not supplied.   This  op-
                      tion is enabled by default.
              vvaarrrreeddiirr__cclloossee
                      If  set, the shell automatically closes file descriptors
                      assigned using the  _{_v_a_r_n_a_m_e_}  redirection  syntax  (see
                      RREEDDIIRREECCTTIIOONN  in  _b_a_s_h(1))  instead  of leaving them open
                      when the command completes.
              xxppgg__eecchhoo
                      If set, the eecchhoo builtin  expands  backslash-escape  se-
                      quences  by  default.  If the ppoossiixx shell option is also
                      enabled, eecchhoo does not interpret any options.

       ssuussppeenndd [--ff]
              Suspend the execution of this shell until it receives a  SSIIGGCCOONNTT
              signal.   A login shell, or a shell without job control enabled,
              cannot be suspended; the --ff option will override this and  force
              the  suspension.   The  return status is 0 unless the shell is a
              login shell or job control is not enabled and  --ff  is  not  sup-
              plied.

       tteesstt _e_x_p_r
       [[ _e_x_p_r ]]
              Return a status of 0 (true) or 1 (false) depending on the evalu-
              ation  of  the  conditional  expression _e_x_p_r.  Each operator and
              operand must be a separate argument.  Expressions  are  composed
              of  the primaries described in _b_a_s_h(1) under CCOONNDDIITTIIOONNAALL EEXXPPRREESS--
              SSIIOONNSS.  tteesstt does not accept any options, nor does it accept and
              ignore an argument of ---- as signifying the end of options.

              Expressions may  be  combined  using  the  following  operators,
              listed  in  decreasing  order of precedence.  The evaluation de-
              pends on the number of arguments; see below.  tteesstt uses operator
              precedence when there are five or more arguments.
              !! _e_x_p_r True if _e_x_p_r is false.
              (( _e_x_p_r ))
                     Returns the value of _e_x_p_r.  This may be used to  override
                     normal operator precedence.
              _e_x_p_r_1 -aa _e_x_p_r_2
                     True if both _e_x_p_r_1 and _e_x_p_r_2 are true.
              _e_x_p_r_1 -oo _e_x_p_r_2
                     True if either _e_x_p_r_1 or _e_x_p_r_2 is true.

              tteesstt and [[ evaluate conditional expressions using a set of rules
              based on the number of arguments.

              0 arguments
                     The expression is false.
              1 argument
                     The expression is true if and only if the argument is not
                     null.
              2 arguments
                     If the first argument is !!, the expression is true if and
                     only  if the second argument is null.  If the first argu-
                     ment is one of the unary conditional operators listed  in
                     _b_a_s_h(1)  under CCOONNDDIITTIIOONNAALL EEXXPPRREESSSSIIOONNSS, the expression is
                     true if the unary test is true.  If the first argument is
                     not a valid unary conditional operator, the expression is
                     false.
              3 arguments
                     The following conditions are applied in the order listed.
                     If the second argument is one of the  binary  conditional
                     operators  listed  in  _b_a_s_h(1)  under CCOONNDDIITTIIOONNAALL EEXXPPRREESS--
                     SSIIOONNSS, the result of the expression is the result of  the
                     binary  test  using  the  first  and  third  arguments as
                     operands.  The --aa and --oo operators are considered  binary
                     operators  when  there are three arguments.  If the first
                     argument is !!, the value is the negation of the two-argu-
                     ment test using the second and third arguments.   If  the
                     first argument is exactly (( and the third argument is ex-
                     actly  )), the result is the one-argument test of the sec-
                     ond argument.  Otherwise, the expression is false.
              4 arguments
                     The following conditions are applied in the order listed.
                     If the first argument is !!, the result is the negation of
                     the three-argument expression composed of  the  remaining
                     arguments.   If  the  first argument is exactly (( and the
                     fourth argument is exactly )), the result is the two-argu-
                     ment test of the second and third arguments.   Otherwise,
                     the  expression  is  parsed  and  evaluated  according to
                     precedence using the rules listed above.
              5 or more arguments
                     The expression  is  parsed  and  evaluated  according  to
                     precedence using the rules listed above.

              When the shell is in posix mode, or if the expression is part of
              the [[[[ command, the << and >> operators sort using the current lo-
              cale.   If  the  shell is not in posix mode, the tteesstt and [[ com-
              mands sort lexicographically using ASCII ordering.

              The historical operator-precedence parsing with 4 or more  argu-
              ments  can  lead  to ambiguities when it encounters strings that
              look like primaries.  The POSIX standard has deprecated  the  --aa
              and  --oo  primaries and enclosing expressions within parentheses.
              Scripts should no longer use them.  It's much more  reliable  to
              restrict  test  invocations  to a single primary, and to replace
              uses of --aa and --oo with the shell's &&&& and |||| list operators.

       ttiimmeess  Print the accumulated user and system times for  the  shell  and
              for processes run from the shell.  The return status is 0.

       ttrraapp [--llppPP] [[_a_c_t_i_o_n] _s_i_g_s_p_e_c ...]
              The _a_c_t_i_o_n is a command that is read and executed when the shell
              receives  any  of the signals _s_i_g_s_p_e_c.  If _a_c_t_i_o_n is absent (and
              there is a single _s_i_g_s_p_e_c) or --, each specified _s_i_g_s_p_e_c is reset
              to the value it had when the shell was started.   If  _a_c_t_i_o_n  is
              the  null string the signal specified by each _s_i_g_s_p_e_c is ignored
              by the shell and by the commands it invokes.

              If no arguments are supplied, ttrraapp displays the actions  associ-
              ated with each trapped signal as a set of ttrraapp commands that can
              be  reused as shell input to restore the current signal disposi-
              tions.  If --pp is given, and _a_c_t_i_o_n is  not  present,  then  ttrraapp
              displays  the  actions  associated with each _s_i_g_s_p_e_c or, if none
              are supplied, for all trapped signals, as a set of ttrraapp commands
              that can be reused as shell input to restore the current  signal
              dispositions.   The  --PP  option  behaves similarly, but displays
              only the actions associated with each _s_i_g_s_p_e_c argument.  --PP  re-
              quires  at least one _s_i_g_s_p_e_c argument.  The --PP or --pp options may
              be used in a subshell environment (e.g.,  command  substitution)
              and,  as  long  as they are used before ttrraapp is used to change a
              signal's handling, will display the state of its parent's traps.

              The --ll option prints a list of signal  names  and  their  corre-
              sponding  numbers.  Each _s_i_g_s_p_e_c is either a signal name defined
              in <_s_i_g_n_a_l_._h>, or a signal number.  Signal names are case insen-
              sitive and the SSIIGG prefix is optional.  If --ll is  supplied  with
              no _s_i_g_s_p_e_c arguments, it prints a list of valid signal names.

              If  a  _s_i_g_s_p_e_c  is EEXXIITT (0), _a_c_t_i_o_n is executed on exit from the
              shell.  If a _s_i_g_s_p_e_c is DDEEBBUUGG, _a_c_t_i_o_n is executed  before  every
              _s_i_m_p_l_e  _c_o_m_m_a_n_d,  _f_o_r  command, _c_a_s_e command, _s_e_l_e_c_t command, ((
              arithmetic command, [[ conditional command, arithmetic _f_o_r  com-
              mand,  and before the first command executes in a shell function
              (see SSHHEELLLL GGRRAAMMMMAARR in _b_a_s_h(1)).  Refer to the description of the
              eexxttddeebbuugg shell option (see sshhoopptt in _b_a_s_h(1)) for details of  its
              effect on the DDEEBBUUGG trap.  If a _s_i_g_s_p_e_c is RREETTUURRNN, _a_c_t_i_o_n is ex-
              ecuted  each time a shell function or a script executed with the
              .. or ssoouurrccee builtins finishes executing.

              If a _s_i_g_s_p_e_c is EERRRR, _a_c_t_i_o_n  is  executed  whenever  a  pipeline
              (which  may  consist  of  a single simple command), a list, or a
              compound command returns a non-zero exit status, subject to  the
              following  conditions.   The  EERRRR  trap  is  not executed if the
              failed command is part of the command list immediately following
              a wwhhiillee or uunnttiill reserved word, part of the test in an _i_f state-
              ment, part of a command executed in a &&&& or |||| list  except  the
              command  following the final &&&& or ||||, any command in a pipeline
              but the last (subject to the state of  the  ppiippeeffaaiill  shell  op-
              tion),  or if the command's return value is being inverted using
              !!.  These are the same conditions obeyed by the eerrrreexxiitt (--ee) op-
              tion.

              When the shell is not interactive, signals ignored upon entry to
              the shell cannot be trapped or reset.  Interactive shells permit
              trapping signals ignored on entry.  Trapped signals that are not
              being ignored are reset to their original values in  a  subshell
              or  subshell environment when one is created.  The return status
              is false if any _s_i_g_s_p_e_c is invalid; otherwise ttrraapp returns true.

       ttrruuee   Does nothing, returns a 0 status.

       ttyyppee [--aaffttppPP] _n_a_m_e [_n_a_m_e ...]
              Indicate how each _n_a_m_e would be interpreted if used as a command
              name.

              If the --tt option is used, ttyyppee prints a string which is  one  of
              _a_l_i_a_s,  _k_e_y_w_o_r_d, _f_u_n_c_t_i_o_n, _b_u_i_l_t_i_n, or _f_i_l_e if _n_a_m_e is an alias,
              shell reserved word, function, builtin, or executable file,  re-
              spectively.   If  the _n_a_m_e is not found, ttyyppee prints nothing and
              returns a non-zero exit status.

              If the --pp option is used, ttyyppee either returns  the  pathname  of
              the  executable  file that would be found by searching $$PPAATTHH for
              _n_a_m_e or nothing if would not return _f_i_l_e.  The --PP option  forces
              a  PPAATTHH search for each _n_a_m_e, even if would not return _f_i_l_e.  If
              _n_a_m_e is present in the table of hashed commands, --pp and --PP print
              the hashed value, which is not necessarily the file that appears
              first in PPAATTHH.

              If the --aa option is used, ttyyppee prints all  of  the  places  that
              contain  a  command named _n_a_m_e.  This includes aliases, reserved
              words, functions, and builtins, but the path search options  (--pp
              and  --PP)  can  be  supplied to restrict the output to executable
              files.  ttyyppee does not consult the table of hashed commands  when
              using --aa with --pp, and only performs a PPAATTHH search for _n_a_m_e.

              The --ff option suppresses shell function lookup, as with the ccoomm--
              mmaanndd  builtin.   ttyyppee  returns  true if all of the arguments are
              found, false if any are not found.

       uulliimmiitt [--HHSS] --aa
       uulliimmiitt [--HHSS] [--bbccddeeffiikkllmmnnppqqrrssttuuvvxxPPRRTT [_l_i_m_i_t]]
              Provides control over the resources available to the  shell  and
              to processes it starts, on systems that allow such control.

              The  --HH and --SS options specify whether the hard or soft limit is
              set for the given resource.  A hard limit cannot be increased by
              a non-root user once it is set; a soft limit may be increased up
              to the value of the hard limit.  If neither --HH nor --SS is  speci-
              fied, uulliimmiitt sets both the soft and hard limits.

              The value of _l_i_m_i_t can be a number in the unit specified for the
              resource  or one of the special values hhaarrdd, ssoofftt, or uunnlliimmiitteedd,
              which stand for the current hard limit, the current soft  limit,
              and  no limit, respectively.  If _l_i_m_i_t is omitted, uulliimmiitt prints
              the current value of the soft limit of the resource, unless  the
              --HH  option  is given.  When more than one resource is specified,
              the limit name and unit, if appropriate, are printed before  the
              value.  Other options are interpreted as follows:
              --aa     Report all current limits; no limits are set.
              --bb     The maximum socket buffer size.
              --cc     The maximum size of core files created.
              --dd     The maximum size of a process's data segment.
              --ee     The maximum scheduling priority (
              --ff     The  maximum  size  of files written by the shell and its
                     children.
              --ii     The maximum number of pending signals.
              --kk     The maximum number of kqueues that may be allocated.
              --ll     The maximum size that may be locked into memory.
              --mm     The maximum resident set size (many systems do not  honor
                     this limit).
              --nn     The maximum number of open file descriptors (most systems
                     do not allow this value to be set).
              --pp     The pipe size in 512-byte blocks (this may not be set).
              --qq     The maximum number of bytes in POSIX message queues.
              --rr     The maximum real-time scheduling priority.
              --ss     The maximum stack size.
              --tt     The maximum amount of cpu time in seconds.
              --uu     The  maximum  number  of  processes available to a single
                     user.
              --vv     The maximum amount of virtual  memory  available  to  the
                     shell and, on some systems, to its children.
              --xx     The maximum number of file locks.
              --PP     The maximum number of pseudoterminals.
              --RR     The  maximum  time  a  real-time  process  can run before
                     blocking, in microseconds.
              --TT     The maximum number of threads.

              If _l_i_m_i_t is supplied, and the --aa option is not  used,  _l_i_m_i_t  is
              the  new  value of the specified resource.  If no option is sup-
              plied, then --ff is assumed.

              Values are in 1024-byte increments, except for --tt, which  is  in
              seconds;  --RR, which is in microseconds; --pp, which is in units of
              512-byte blocks; --PP, --TT, --bb, --kk, --nn, and --uu, which are  unscaled
              values;  and,  when  in  posix  mode,  --cc  and  --ff, which are in
              512-byte increments.  The return status is 0 unless  an  invalid
              option or argument is supplied, or an error occurs while setting
              a new limit.

       uummaasskk [--pp] [--SS] [_m_o_d_e]
              Set  the user file-creation mask to _m_o_d_e.  If _m_o_d_e begins with a
              digit, it is interpreted as an octal number; otherwise it is in-
              terpreted as a symbolic mode mask similar to  that  accepted  by
              _c_h_m_o_d(1).  If _m_o_d_e is omitted, uummaasskk prints the current value of
              the mask.  The --SS option without a _m_o_d_e argument prints the mask
              in a symbolic format; the default output is an octal number.  If
              the --pp option is supplied, and _m_o_d_e is omitted, the output is in
              a  form  that may be reused as input.  The return status is zero
              if the mode was successfully changed or if no _m_o_d_e argument  was
              supplied, and non-zero otherwise.

       uunnaalliiaass [-aa] [_n_a_m_e ...]
              Remove  each  _n_a_m_e  from  the list of defined aliases.  If --aa is
              supplied, remove all alias definitions.   The  return  value  is
              true unless a supplied _n_a_m_e is not a defined alias.

       uunnsseett [-ffvv] [-nn] [_n_a_m_e ...]
              For  each  _n_a_m_e,  remove the corresponding variable or function.
              If the --vv option is given, each _n_a_m_e refers to a shell variable,
              and that variable is removed.  If --ff  is  specified,  each  _n_a_m_e
              refers  to  a shell function, and the function definition is re-
              moved.  If the --nn option is supplied, and  _n_a_m_e  is  a  variable
              with  the  _n_a_m_e_r_e_f attribute, _n_a_m_e will be unset rather than the
              variable it references.  --nn has no effect if the  --ff  option  is
              supplied.   Read-only  variables and functions may not be unset.
              When variables or functions are removed, they are  also  removed
              from  the  environment passed to subsequent commands.  If no op-
              tions are supplied, each _n_a_m_e refers to a variable; if there  is
              no  variable by that name, a function with that name, if any, is
              unset.  Some shell variables  may  not  be  unset.   If  any  of
              BBAASSHH__AALLIIAASSEESS,  BBAASSHH__AARRGGVV00,  BBAASSHH__CCMMDDSS,  BBAASSHH__CCOOMMMMAANNDD,  BBAASSHH__SSUUBB--
              SSHHEELLLL,  BBAASSHHPPIIDD,   CCOOMMPP__WWOORRDDBBRREEAAKKSS,   DDIIRRSSTTAACCKK,   EEPPOOCCHHRREEAALLTTIIMMEE,
              EEPPOOCCHHSSEECCOONNDDSS,  FFUUNNCCNNAAMMEE,  GGRROOUUPPSS,  HHIISSTTCCMMDD, LLIINNEENNOO, RRAANNDDOOMM, SSEECC--
              OONNDDSS, or SSRRAANNDDOOMM are unset, they lose their special  properties,
              even  if  they  are subsequently reset.  The exit status is true
              unless a _n_a_m_e is readonly or may not be unset.

       wwaaiitt [--ffnn] [--pp _v_a_r_n_a_m_e] [_i_d ...]
              Wait for each specified child process _i_d and return the termina-
              tion status of the last _i_d.  Each _i_d may be a process ID _p_i_d  or
              a  job  specification  _j_o_b_s_p_e_c;  if  a jobspec is supplied, wwaaiitt
              waits for all processes in the job.

              If no options or _i_ds are supplied, wwaaiitt waits  for  all  running
              background  jobs  and the last-executed process substitution, if
              its process id is the same as $$!!, and the return status is zero.

              If the --nn option is supplied, wwaaiitt waits  for  any  one  of  the
              given _i_ds or, if no _i_ds are supplied, any job or process substi-
              tution, to complete and returns its exit status.  If none of the
              supplied  _i_ds is a child of the shell, or if no _i_ds are supplied
              and the shell has no unwaited-for children, the exit  status  is
              127.

              If  the  --pp  option is supplied, wwaaiitt assigns the process or job
              identifier of the job for which the exit status is  returned  to
              the  variable  _v_a_r_n_a_m_e  named by the option argument.  The vari-
              able, which cannot be readonly, will be unset initially,  before
              any  assignment.   This is useful only when used with the --nn op-
              tion.

              Supplying the --ff option, when job  control  is  enabled,  forces
              wwaaiitt  to wait for each _i_d to terminate before returning its sta-
              tus, instead of returning when it changes status.

              If none of the _i_ds specify  one  of  the  shell's  active  child
              processes,  the return status is 127.  If wwaaiitt is interrupted by
              a signal, any _v_a_r_n_a_m_e will remain unset, and the  return  status
              will be greater than 128, as described under SSIIGGNNAALLSS in _b_a_s_h(1).
              Otherwise, the return status is the exit status of the last _i_d.

SSHHEELLLL CCOOMMPPAATTIIBBIILLIITTYY MMOODDEE
       Bash-4.0  introduced the concept of a _s_h_e_l_l _c_o_m_p_a_t_i_b_i_l_i_t_y _l_e_v_e_l, speci-
       fied as a set of options to the shopt builtin (ccoommppaatt3311, ccoommppaatt3322, ccoomm--
       ppaatt4400, ccoommppaatt4411, and so on).  There is only one  current  compatibility
       level -- each option is mutually exclusive.  The compatibility level is
       intended  to allow users to select behavior from previous versions that
       is incompatible with newer versions while they migrate scripts  to  use
       current  features  and behavior.  It's intended to be a temporary solu-
       tion.

       This section does not mention behavior that is standard for a  particu-
       lar  version  (e.g., setting ccoommppaatt3322 means that quoting the right hand
       side of the regexp matching operator quotes special  regexp  characters
       in  the word, which is default behavior in bash-3.2 and subsequent ver-
       sions).

       If a user enables, say, ccoommppaatt3322, it may affect the behavior  of  other
       compatibility  levels  up  to  and  including the current compatibility
       level.  The idea is that each  compatibility  level  controls  behavior
       that  changed  in that version of bbaasshh, but that behavior may have been
       present in earlier versions.  For instance, the change to  use  locale-
       based  comparisons  with  the  [[[[ command came in bash-4.1, and earlier
       versions used ASCII-based comparisons, so enabling ccoommppaatt3322 will enable
       ASCII-based comparisons as well.  That granularity may  not  be  suffi-
       cient  for  all uses, and as a result users should employ compatibility
       levels carefully.  Read the documentation for a particular  feature  to
       find out the current behavior.

       Bash-4.3  introduced  a new shell variable: BBAASSHH__CCOOMMPPAATT.  The value as-
       signed to this variable (a decimal version number like 4.2, or an inte-
       ger corresponding to the ccoommppaatt_N_N option, like 42) determines the  com-
       patibility level.

       Starting with bash-4.4, bbaasshh began deprecating older compatibility lev-
       els.  Eventually, the options will be removed in favor of BBAASSHH__CCOOMMPPAATT.

       Bash-5.0  was the final version for which there was an individual shopt
       option for the previous version.  BBAASSHH__CCOOMMPPAATT is the only mechanism  to
       control the compatibility level in versions newer than bash-5.0.

       The  following  table describes the behavior changes controlled by each
       compatibility level setting.  The ccoommppaatt_N_N tag is used as shorthand for
       setting the compatibility level to _N_N using one of the following mecha-
       nisms.  For versions prior to bash-5.0, the compatibility level may  be
       set  using  the  corresponding ccoommppaatt_N_N shopt option.  For bash-4.3 and
       later versions, the BBAASSHH__CCOOMMPPAATT variable is preferred, and  it  is  re-
       quired for bash-5.1 and later versions.

       ccoommppaatt3311
              +o      Quoting the rhs of the [[[[ command's regexp matching oper-
                     ator (=) has no special effect.

       ccoommppaatt3322
              +o      The  <<  and >> operators to the [[[[ command do not consider
                     the current locale when comparing strings; they use ASCII
                     ordering.

       ccoommppaatt4400
              +o      The << and >> operators to the [[[[ command do  not  consider
                     the current locale when comparing strings; they use ASCII
                     ordering.  BBaasshh versions prior to bash-4.1 use ASCII col-
                     lation  and _s_t_r_c_m_p(3); bash-4.1 and later use the current
                     locale's collation sequence and _s_t_r_c_o_l_l(3).

       ccoommppaatt4411
              +o      In posix mode, ttiimmee may be followed by options and  still
                     be recognized as a reserved word (this is POSIX interpre-
                     tation 267).
              +o      In _p_o_s_i_x mode, the parser requires that an even number of
                     single  quotes  occur  in  the  _w_o_r_d portion of a double-
                     quoted parameter expansion and treats them specially,  so
                     that  characters  within the single quotes are considered
                     quoted (this is POSIX interpretation 221).

       ccoommppaatt4422
              +o      The replacement string in double-quoted pattern substitu-
                     tion does not undergo quote removal, as it does  in  ver-
                     sions after bash-4.2.
              +o      In  posix mode, single quotes are considered special when
                     expanding the _w_o_r_d portion of a  double-quoted  parameter
                     expansion  and  can  be  used to quote a closing brace or
                     other special character (this is part of POSIX  interpre-
                     tation  221);  in  later  versions, single quotes are not
                     special within double-quoted word expansions.

       ccoommppaatt4433
              +o      Word expansion errors  are  considered  non-fatal  errors
                     that  cause  the  current  command to fail, even in posix
                     mode (the default behavior is to make them  fatal  errors
                     that cause the shell to exit).
              +o      When   executing   a   shell  function,  the  loop  state
                     (while/until/etc.)  is not reset, so bbrreeaakk or ccoonnttiinnuuee in
                     that function will break or continue loops in the calling
                     context.  Bash-4.4 and later reset the loop state to pre-
                     vent this.

       ccoommppaatt4444
              +o      The shell sets  up  the  values  used  by  BBAASSHH__AARRGGVV  and
                     BBAASSHH__AARRGGCC  so  they  can expand to the shell's positional
                     parameters even if extended debugging  mode  is  not  en-
                     abled.
              +o      A  subshell  inherits  loops  from its parent context, so
                     bbrreeaakk or  ccoonnttiinnuuee  will  cause  the  subshell  to  exit.
                     Bash-5.0  and  later  reset the loop state to prevent the
                     exit
              +o      Variable assignments preceding builtins like  eexxppoorrtt  and
                     rreeaaddoonnllyy that set attributes continue to affect variables
                     with the same name in the calling environment even if the
                     shell is not in posix mode.

       ccoommppaatt5500
              +o      Bash-5.1  changed  the way $$RRAANNDDOOMM is generated to intro-
                     duce slightly more randomness.  If the shell  compatibil-
                     ity level is set to 50 or lower, it reverts to the method
                     from  bash-5.0 and previous versions, so seeding the ran-
                     dom number generator by assigning a value to RRAANNDDOOMM  will
                     produce the same sequence as in bash-5.0.
              +o      If  the  command hash table is empty, bash versions prior
                     to bash-5.1 printed an informational message to that  ef-
                     fect,  even  when  producing output that can be reused as
                     input.  Bash-5.1 suppresses that message when the --ll  op-
                     tion is supplied.

       ccoommppaatt5511
              +o      The  uunnsseett  builtin  treats  attempts to unset array sub-
                     scripts @@ and ** differently depending on whether the  ar-
                     ray  is  indexed  or associative, and differently than in
                     previous versions.
              +o      Arithmetic commands ( ((((...)))) ) and the expressions in an
                     arithmetic for statement can be expanded more than once.
              +o      Expressions used as arguments to arithmetic operators  in
                     the  [[[[  conditional  command  can  be expanded more than
                     once.
              +o      The expressions in substring  parameter  brace  expansion
                     can be expanded more than once.
              +o      The expressions in the $$((((...)))) word expansion can be ex-
                     panded more than once.
              +o      Arithmetic  expressions  used as indexed array subscripts
                     can be expanded more than once.
              +o      tteesstt --vv, when given an argument of AA[[@@]], where  AA  is  an
                     existing associative array, will return true if the array
                     has  any set elements.  Bash-5.2 will look for and report
                     on a key named @@.
              +o      The  ${_p_a_r_a_m_e_t_e_r[[::]]==_v_a_l_u_e}  word  expansion  will  return
                     _v_a_l_u_e,  before any variable-specific transformations have
                     been performed (e.g., converting to lowercase).  Bash-5.2
                     will return the final value assigned to the variable.
              +o      Parsing command substitutions will behave as if  extended
                     globbing (see the description of the sshhoopptt builtin above)
                     is  enabled,  so that parsing a command substitution con-
                     taining an extglob pattern (say, as part of a shell func-
                     tion) will not fail.  This assumes the intent is  to  en-
                     able  extglob before the command is executed and word ex-
                     pansions are performed.  It will fail at  word  expansion
                     time  if extglob hasn't been enabled by the time the com-
                     mand is executed.

       ccoommppaatt5522
              +o      The tteesstt builtin uses its historical algorithm  to  parse
                     parenthesized  subexpressions when given five or more ar-
                     guments.
              +o      If the --pp or --PP option is supplied to the  bbiinndd  builtin,
                     bbiinndd treats any arguments remaining after option process-
                     ing  as  bindable command names, and displays any key se-
                     quences bound to those commands, instead of treating  the
                     arguments as key sequences to bind.

SSEEEE AALLSSOO
       bash(1), sh(1)

GNU Bash 5.2                    2023 January 27               _B_A_S_H___B_U_I_L_T_I_N_S(1)
