1  /* Copyright (C) 2004, 2007, 2009-2023 Free Software Foundation, Inc.
       2  
       3     Written by Yoann Vandoorselaere <yoann@prelude-ids.org>.
       4  
       5     This file is free software: you can redistribute it and/or modify
       6     it under the terms of the GNU Lesser General Public License as
       7     published by the Free Software Foundation; either version 2.1 of the
       8     License, or (at your option) any later version.
       9  
      10     This file 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 Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public License
      16     along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
      17  
      18  #ifdef HAVE_CONFIG_H
      19  # include <config.h>
      20  #endif
      21  
      22  /* Specification.  */
      23  #include <string.h>
      24  
      25  char *
      26  strsep (char **stringp, const char *delim)
      27  {
      28    char *start = *stringp;
      29    char *ptr;
      30  
      31    if (start == NULL)
      32      return NULL;
      33  
      34    /* Optimize the case of no delimiters.  */
      35    if (delim[0] == '\0')
      36      {
      37        *stringp = NULL;
      38        return start;
      39      }
      40  
      41    /* Optimize the case of one delimiter.  */
      42    if (delim[1] == '\0')
      43      ptr = strchr (start, delim[0]);
      44    else
      45      /* The general case.  */
      46      ptr = strpbrk (start, delim);
      47    if (ptr == NULL)
      48      {
      49        *stringp = NULL;
      50        return start;
      51      }
      52  
      53    *ptr = '\0';
      54    *stringp = ptr + 1;
      55  
      56    return start;
      57  }