pd.if.org Git - zos/blob - klib/strtok.c

   1 #include <string.h>
   2
   3 char *strtok(char *s1, const char *s2) {
   4         static char *tmp = NULL;
   5         const char *p = s2;
   6
   7         if (s1 != NULL) {
   8                 /* new string */
   9                 tmp = s1;
  10         } else {
  11                 /* old string continued */
  12                 if (tmp == NULL) {
  13                         /* No old string, no new string, nothing to do */
  14                         return NULL;
  15                 }
  16                 s1 = tmp;
  17         }
  18
  19         /* skipping leading s2 characters */
  20         while (*p && *s1) {
  21                 if ( *s1 == *p ) {
  22                         /* found seperator; skip and start over */
  23                         ++s1;
  24                         p = s2;
  25                         continue;
  26                 }
  27                 ++p;
  28         }
  29
  30         if (!*s1) {
  31                 /* no more to parse */
  32                 return ( tmp = NULL );
  33         }
  34
  35         /* skipping non-s2 characters */
  36         tmp = s1;
  37         while (*tmp) {
  38                 p = s2;
  39                 while (*p) {
  40                         if (*tmp == *p++) {
  41                                 /* found seperator; overwrite with '\0', position tmp, return */
  42                                 *tmp++ = '\0';
  43                                 return s1;
  44                         }
  45                 }
  46                 ++tmp;
  47         }
  48
  49         /* parsed to end of string */
  50         tmp = NULL;
  51         return s1;
  52 }