gl/strsep.c

   1 /* Copyright (C) 2004, 2007, 2009, 2010 Free Software Foundation, Inc.
   2
   3    Written by Yoann Vandoorselaere <yoann@prelude-ids.org>.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3, or (at your option)
   8    any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software Foundation,
  17    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  18
  19 #ifdef HAVE_CONFIG_H
  20 # include <config.h>
  21 #endif
  22
  23 /* Specification.  */
  24 #include <string.h>
  25
  26 char *
  27 strsep (char **stringp, const char *delim)
  28 {
  29   char *start = *stringp;
  30   char *ptr;
  31
  32   if (start == NULL)
  33     return NULL;
  34
  35   /* Optimize the case of no delimiters.  */
  36   if (delim[0] == '\0')
  37     {
  38       *stringp = NULL;
  39       return start;
  40     }
  41
  42   /* Optimize the case of one delimiter.  */
  43   if (delim[1] == '\0')
  44     ptr = strchr (start, delim[0]);
  45   else
  46     /* The general case.  */
  47     ptr = strpbrk (start, delim);
  48   if (ptr == NULL)
  49     {
  50       *stringp = NULL;
  51       return start;
  52     }
  53
  54   *ptr = '\0';
  55   *stringp = ptr + 1;
  56
  57   return start;
  58 }