# This pod file is used in Debian to generate C<raku> man page when
# building C<rakudo> package. At that stage only Perl5 C<pod2man>
# program is available. So this file must follow Perl5's pod syntax.
#
# See https://github.com/rakudo/rakudo/pull/4080#issuecomment-736682853
# for more information.

=head1 NAME

raku - Rakudo Raku Compiler

=encoding UTF-8

=head1 SYNOPSIS

 raku [switches] [--] [programfile] [arguments]

=head1 DESCRIPTION

With no arguments, enters a REPL. With a C<[programfile]> or the C<-e>
option, compiles the given program and by default also executes the
compiled code.

  -c                   check syntax only (runs BEGIN and CHECK blocks)
  --doc                extract documentation and print it as text
  -e program           one line of program, strict is enabled by default
  -h, --help           display this help text
  -n                   run program once for each line of input
  -p                   same as -n, but also print $_ at the end of lines
  -I path              adds the path to the module search path
  -M module            loads the module prior to running the program
  --target=[stage]     specify compilation stage to emit
  --optimize=[level]   use the given level of optimization (0..3)
  --encoding=[mode]    specify string encoding mode
  -o, --output=[name]  specify name of output file
  -v, --version        display version information
  --stagestats         display time spent in the compilation stages
  --ll-exception       display a low level backtrace on errors
  --profile            write profile information as HTML file (MoarVM)
  --profile-filename   provide a different filename (also allows .json)
  --doc=[module]       Use Pod::To::[module] to render inline documentation.
  --full-cleanup       try to free all memory and exit cleanly (MoarVM)
  --debug-port=port    listen for incoming debugger connections (MoarVM)
  --debug-suspend      pause execution at the entry point (MoarVM)
  --tracing            output a line to stderr on every interpreter instr (only
                       if enabled in MoarVM)

Note that only boolean single-letter options may be bundled.

The supported values for C<--target> are:

  Target     Backend  Description
  ======     =======  ===========
  parse      all      a representation of the parse tree
  ast        all      an abstract syntax tree (before optimizations)
  optimize   all      an abstract syntax tree (after optimizations)

  mbc        MoarVM   MoarVM byte code
  jar        JVM      JVM archive

For C<--profile-filename>, specifying a name ending in C<.json> will write a raw
JSON profile dump. The default if this is omitted is C<profile-I<[timestamp]>.html>.

=head1 ENVIRONMENT VARIABLES

Rakudo's behavior can be tweaked by a (growing) number of environment variables;
this section attempts to document all those currently in use. They are
interpreter specific in all cases, except where some use conventional names
such as C<PATH>.

The underlying virtual machine is also sensitive to a series of environment
variables; they are listed L<in this wiki
page|https://github.com/rakudo/rakudo/wiki/dev-env-vars#moarvm>.

=head2 Module loading

=over

=item C<RAKUDOLIB>, C<RAKULIB> (I<Str>; F<src/core/Inc.pm>)

C<RAKUDOLIB> and C<RAKULIB> append a comma-delimited list of paths to the
search list for modules. C<RAKUDOLIB> is evaluated first. B<NOTE:> These env
vars were added in the Rakudo compiler in version 2020.05. The deprecated older
env var C<PERL6LIB> is still available.

=item C<RAKUDO_MODULE_DEBUG> (I<Bool>; F<src/Perl6/ModuleLoader.nqp>)

If true, causes the module loader to print debugging information to standard
error.

=back

=head2 Error message verbosity and strictness

=over

=item C<RAKU_EXCEPTIONS_HANDLER>

If present, the C<print_exception> routine
will use a class of that name to process the exception for output. Rakudo
currently ships with C<Exceptions::JSON> (invoked by setting this variable to
C<JSON>), to override the default output. B<NOTE:> This env var was added in
version 6.e.  Early implementation has been available in Rakudo compiler
as of version 2019.12, and before that it was available as
C<PERL6_EXCEPTIONS_HANDLER>.

=item C<RAKUDO_NO_DEPRECATIONS> (I<Bool>; F<src/core.c/Deprecations.pm6>)

If true, suppresses deprecation warnings triggered by the C<is DEPRECATED>
trait.

=item C<RAKUDO_DEPRECATIONS_FATAL> (I<Bool>; F<src/core.c/Deprecations.pm6>)

If true, deprecation warnings become thrown exceptions.

=item C<RAKUDO_VERBOSE_STACKFRAME> (I<UInt>; F<src/core.c/Backtrace.pm6>)

Displays source code in stack frames surrounded by the specified number of
lines of context; for instance C<RAKUDO_VERBOSE_STACKFRAME = 1> will use one
context line.

=item C<RAKUDO_BACKTRACE_SETTING> (I<Bool>; F<src/core.c/Backtrace.pm6>)

Controls whether C<.setting> files are included in backtraces.

=back

=head2 Affecting precompilation

=over

=item C<RAKUDO_PREFIX> (I<Str>; F<src/core.c/CompUnit/RepositoryRegistry.pm6>)

When this is set, Rakudo will look for the standard repositories (perl, vendor,
site) in the specified directory. This is intended as an escape hatch for
build-time bootstrapping issues, where Rakudo may be built as an unprivileged
user without write access to the runtime paths in NQP's config.

=item C<RAKUDO_PRECOMP_DIST> (F<src/core.c/CompUnit/PrecompilationRepository.pm6>)
=item C<RAKUDO_PRECOMP_LOADING> (F<src/core.c/CompUnit/PrecompilationRepository.pm6>)
=item C<RAKUDO_PRECOMP_WITH> (F<src/core.c/CompUnit/PrecompilationRepository.pm6>)

These are internal variables for passing serialized state to precompilation jobs
in child processes. Please do not set them manually.

=item C<RAKUDO_LOG_PRECOMP>

If set to 1, diagnostic information about the precompilation process is
emitted.

=back

=head2 Line editor

=over

=item C<RAKUDO_LINE_EDITOR>

This specifies the preferred line editor to use; valid values are C<Readline>,
C<Linenoise>, C<LineEditor>, and C<none>. A value of C<none> is useful if you
want to avoid the recommendation message upon REPL startup.

=item C<RAKUDO_DISABLE_MULTILINE>

If set to 1, will disable multiline input for the REPL.

=item C<RAKUDO_HIST>

This specifies the location of the history file used by the line editor; the
default is C<~/.raku/rakudo-history>.  Before Rakudo version 2020.02 the
default was C<~/.perl6/rakudo-history>.  If the older default file exists and
the newer one does not, it will be automatically migrated.

=back

=head2 Other

=over

=item C<RAKUDO_DEFAULT_READ_ELEMS>

This specifies the default number of characters to read on an
L«C<IO::Handle>|/type/IO::Handle» by setting the
L«C<$*DEFAULT-READ-ELEMS>|/language/variables#$*DEFAULT-READ-ELEMS» dynamic
variable.

=item C<RAKUDO_ERROR_COLOR> (I<Bool>; F<src/core.c/Exception.pm6>)

Controls whether to emit ANSI codes for error highlighting. Defaults to true
if unset, except on Windows.

=item C<RAKUDO_MAX_THREADS> (I<UInt>; F<src/core.c/ThreadPoolScheduler.pm6>)

Indicates the maximum number of threads used by default when creating a
C<ThreadPoolScheduler>. Defaults to 64.

=item C<TMPDIR>, C<TEMP>, C<TMP> (I<Str>; F<src/core.c/IO/Spec/>)

The C<IO::Spec::Unix.tmpdir> method will return C<$TMPDIR> if it points to a
directory with full access permissions for the current user, with a fallback
default of C<'/tmp'>.

C<IO::Spec::Cygwin> and C<IO::Spec::Win32> use more Windows-appropriate lists
which also include the C<%TEMP%> and C<%TMP%> environment variables.

=item C<PATH>, C<Path> (I<Str>; F<src/core.c/IO/Spec/>)

The C<IO::Spec::Unix.path> method splits C<$PATH> as a
shell would; i.e. as a colon-separated list. C<IO::Spec::Cygwin> inherits this
from C<IO::Spec::Unix>. C<IO::Spec::Win32.path> will read the first defined of
either C<%PATH%> or C<%Path%> as a semicolon-delimited list.

=item C<RAKUDO_SNAPPER>

Indicates the period in which the telemetry snapper will take a snapshot.
Defaults to .1 for 10 snapshots per second.

=item C<RAKUDO_HOME>

Allows one to override the Raku installation path. Defaults to
C<[rakudo_executable_dir]/../share/perl6> in relocatable builds and the
absolute path to that folder in non-relocatable builds.

=item C<NQP_HOME>

Allows one to override the NQP installation path. Defaults to
C<[rakudo_executable_dir]/../share/nqp> in relocatable builds and the absolute
path to that folder in non-relocatable builds.

=back

=head1 WINDOWS PECULIARITIES

=head2 Non-console applications

On Windows programs are compiled to either be I<console> applications or
I<non-console> applications. I<Console> applications always open a console
window. There is no straightforward way to suppress this window.

Rakudo provides a separate set of executables suffixed with a C<'w'>
(C<rakuw.exe>, C<rakudow.exe>, ...) that are compiled as I<non-console>
applications. These do not spawn this console window.

B<WARNING> By default these I<non-console> applications will silently swallow
everything that is printed to C<STDOUT> and C<STDERR>.

To receive the output of the program it suffices to redirect it externally:

  rakuw.exe script.raku >stdout.txt 2>stderr.txt

=head1 AUTHORS

Written by the Rakudo contributors, see the CREDITS file.

This manual page was written by Reini Urban, Moritz Lenz and the Rakudo
contributors.

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