strtok.c

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/*-
 * Copyright (c) 2002-2018 The UbixOS Project.
 * All rights reserved.
 *
 * This was developed by Christopher W. Olsen for the UbixOS Project.
 *
 * Redistribution and use in source and binary forms, with or without modification, are permitted
 * provided that the following conditions are met:
 *
 * 1) Redistributions of source code must retain the above copyright notice, this list of
 *    conditions, the following disclaimer and the list of authors.
 * 2) Redistributions in binary form must reproduce the above copyright notice, this list of
 *    conditions, the following disclaimer and the list of authors in the documentation and/or
 *    other materials provided with the distribution.
 * 3) Neither the name of the UbixOS Project nor the names of its contributors may be used to
 *    endorse or promote products derived from this software without specific prior written
 *    permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
#include <string.h>
#include <sys/types.h>
 
char *strtok_r(char *s, const char *delim, char **last) {
  char *spanp, *tok;
  int c, sc;
 
  if (s == NULL && (s = *last) == NULL)
    return (NULL);
 
  /*
   * Skip (span) leading delimiters (s += strspn(s, delim), sort of).
   */
  cont: c = *s++;
  for (spanp = (char *) delim; (sc = *spanp++) != 0;) {
    if (c == sc)
      goto cont;
  }
 
  if (c == 0) { /* no non-delimiter characters */
    *last = NULL;
    return (NULL);
  }
  tok = s - 1;
 
  /*
   * Scan token (scan for delimiters: s += strcspn(s, delim), sort of).
   * Note that delim must have one NUL; we stop if we see that, too.
   */
  for (;;) {
    c = *s++;
    spanp = (char *) delim;
    do {
      if ((sc = *spanp++) == c) {
        if (c == 0)
          s = NULL;
        else
          s[-1] = '\0';
        *last = s;
        return (tok);
      }
    } while (sc != 0);
  }
  /* NOTREACHED */
  return (NULL);
}
 
char *strtok(char *s, const char *delim) {
  static char *last;
  return (strtok_r(s, delim, &last));
}