gnupg/common/strsep.c

/* strsep.c - Replacement for strsep().
 * Copyright (C) 1992, 1993, 1996, 1997, 1998, 1999,
 *               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.  
 */

/* Code taken from glibc-2.3.2/sysdeps/generic/strsep.c and slightly
   modified for use with GnuPG. */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#include <string.h>

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;
}