/***********************************************************************
*                                                                      *
*               This software is part of the ast package               *
*          Copyright (c) 1992-2012 AT&T Intellectual Property          *
*          Copyright (c) 2020-2023 Contributors to ksh 93u+m           *
*                      and is licensed under the                       *
*                 Eclipse Public License, Version 2.0                  *
*                                                                      *
*                A copy of the License is available at                 *
*      https://www.eclipse.org/org/documents/epl-2.0/EPL-2.0.html      *
*         (with md5 checksum 84283fa8859daf213bdda5a9f8d1be1d)         *
*                                                                      *
*                 Glenn Fowler <gsf@research.att.com>                  *
*                  David Korn <dgk@research.att.com>                   *
*                  Martijn Dekker <martijn@inlv.org>                   *
*            Johnothan King <johnothanking@protonmail.com>             *
*                                                                      *
***********************************************************************/
/*
 * David Korn
 * AT&T Bell Laboratories
 *
 * namebase pathname [suffix]
 *
 * print the namebase of a pathname
 */

static const char usage[] =
"[-?\n@(#)$Id: basename (ksh 93u+m) 2022-08-30 $\n]"
"[--catalog?" ERROR_CATALOG "]"
"[+NAME?basename - strip directory and suffix from filenames]"
"[+DESCRIPTION?\bbasename\b removes all leading directory components "
    "from the file name defined by \astring\a. If the file name defined by "
    "\astring\a has a suffix that ends in \asuffix\a, it is removed as "
    "well.]"
"[+?If \astring\a consists solely of \b/\b characters the output will be "
    "a single \b/\b unless \bPATH_LEADING_SLASHES\b returned by "
    "\bgetconf\b(1) is \b1\b and \astring\a consists of multiple \b/\b "
    "characters in which case \b//\b will be output. Otherwise, trailing "
    "\b/\b characters are removed, and if there are any remaining \b/\b "
    "characters in \astring\a, all characters up to and including the last "
    "\b/\b are removed. Finally, if \asuffix\a is specified, and is "
    "identical the end of \astring\a, these characters are removed. The "
    "characters not removed from \astring\a will be written on a single line "
    "to the standard output.]"
"[a:all|multiple?All operands are treated as \astring\a and each modified "
    "pathname is printed on a separate line on the standard output.]"
"[s:suffix?All operands are treated as \astring\a and each modified "
    "pathname, with \asuffix\a removed if it exists, is printed on a "
    "separate line on the standard output.]:[suffix]"
"\n"
"\n string [suffix]\n"
"string ...\n"
"\n"
"[+EXIT STATUS?]"
    "{"
        "[+0?Successful completion.]"
        "[+>0?An error occurred.]"
    "}"
"[+SEE ALSO?\bdirname\b(1), \bgetconf\b(1), \bbasename\b(3)]"
;


#include <cmd.h>

static void namebase(Sfio_t *outfile, char *pathname, char *suffix)
{
	char *first, *last;
	int n=0;
	for(first=last=pathname; *last; last++);
	/* back over trailing '/' */
	if(last>first)
		while(*--last=='/' && last > first);
	if(last==first && *last=='/')
	{
		/* all '/' or "" */
		if(*first=='/')
			if(*++last=='/')	/* keep leading // */
				last++;
	}
	else
	{
		for(first=last++;first>pathname && *first!='/';first--);
		if(*first=='/')
			first++;
		/* check for trailing suffix */
		if(suffix && (n=strlen(suffix)) && n<(last-first))
		{
			if(memcmp(last-n,suffix,n)==0)
				last -=n;
		}
	}
	if(last>first)
		sfwrite(outfile,first,last-first);
	sfputc(outfile,'\n');
}

int
b_basename(int argc, char** argv, Shbltin_t* context)
{
	char*	string;
	char*	suffix = 0;
	int	all = 0;

	cmdinit(argc, argv, context, ERROR_CATALOG, 0);
	for (;;)
	{
		switch (optget(argv, usage))
		{
		case 'a':
			all = 1;
			continue;
		case 's':
			all = 1;
			suffix = opt_info.arg;
			continue;
		case ':':
			error(2, "%s", opt_info.arg);
			break;
		case '?':
			error(ERROR_usage(2), "%s", opt_info.arg);
			UNREACHABLE();
		}
		break;
	}
	argv += opt_info.index;
	argc -= opt_info.index;
	if (error_info.errors || argc < 1 || !all && argc > 2)
	{
		error(ERROR_usage(2), "%s", optusage(NULL));
		UNREACHABLE();
	}
	if (!all)
		namebase(sfstdout, argv[0], argv[1]);
	else
		while (string = *argv++)
			namebase(sfstdout, string, suffix);
	return 0;
}
