notmuch/compat/strsep.c

/* Copyright (C) 1992, 93, 96, 97, 98, 99, 2004 Free Software Foundation, Inc.
 * This file is part of the GNU C Library.
 *
 * The GNU C Library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * The GNU C Library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with the GNU C Library; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
 * 02111-1307 USA.  */

#include <string.h>

/* Taken from glibc 2.6.1 */

char *
strsep (char **stringp, const char *delim)
{
    char *begin, *end;

    begin = *stringp;
    if (begin == NULL)
	return NULL;

    /* A frequent case is when the delimiter string contains only one
     * character.  Here we don't need to call the expensive `strpbrk'
     * function and instead work using `strchr'.  */
    if (delim[0] == '\0' || delim[1] == '\0') {
	char ch = delim[0];

	if (ch == '\0')
	    end = NULL;
	else {
	    if (*begin == ch)
		end = begin;
	    else if (*begin == '\0')
		end = NULL;
	    else
		end = strchr (begin + 1, ch);
	}
    } else
	/* Find the end of the token.  */
	end = strpbrk (begin, delim);

    if (end) {
	/* Terminate the token and set *STRINGP past NUL character.  */
	*end++ = '\0';
	*stringp = end;
    } else
	/* No more delimiters; this is the last token.  */
	*stringp = NULL;

    return begin;
}