reactos/ntoskrnl/rtl/strtok.c

   1 /* $Id$
   2  *
   3  * COPYRIGHT:       See COPYING in the top level directory
   4  * PROJECT:         ReactOS kernel
   5  * FILE:            ntoskrnl/rtl/strtok.c
   6  * PURPOSE:         Unicode and thread safe implementation of strtok
   7  *
   8  * PROGRAMMERS:     David Welch (welch@mcmail.com)
   9  */
  10
  11 /* INCLUDES *****************************************************************/
  12
  13 #include <ntoskrnl.h>
  14 #include <internal/debug.h>
  15
  16
  17 /* FUNCTIONS *****************************************************************/
  18
  19 char* strtok(char *s, const char *delim)
  20 {
  21   const char *spanp;
  22   int c, sc;
  23   char *tok;
  24   static char *last;
  25
  26   if (s == NULL && (s = last) == NULL)
  27     return (NULL);
  28
  29   /*
  30    * Skip (span) leading delimiters (s += strspn(s, delim), sort of).
  31    */
  32  cont:
  33   c = *s++;
  34   for (spanp = delim; (sc = *spanp++) != 0;) {
  35     if (c == sc)
  36       goto cont;
  37   }
  38
  39   if (c == 0) {                 /* no non-delimiter characters */
  40     last = NULL;
  41     return (NULL);
  42   }
  43   tok = s - 1;
  44
  45   /*
  46    * Scan token (scan for delimiters: s += strcspn(s, delim), sort of).
  47    * Note that delim must have one NUL; we stop if we see that, too.
  48    */
  49   for (;;) {
  50     c = *s++;
  51     spanp = delim;
  52     do {
  53       if ((sc = *spanp++) == c) {
  54         if (c == 0)
  55           s = NULL;
  56         else
  57           s[-1] = 0;
  58         last = s;
  59         return (tok);
  60       }
  61     } while (sc != 0);
  62   }
  63   /* NOTREACHED */
  64 }
  65
  66 PWSTR RtlStrtok(PUNICODE_STRING _string, PWSTR _sep,
  67                 PWSTR* temp)
  68 /*
  69  * FUNCTION: Splits a string into tokens
  70  * ARGUMENTS:
  71  *         string = string to operate on
  72  *                  if NULL then continue with previous string
  73  *         sep = Token deliminators
  74  *         temp = Tempory storage provided by the caller
  75  * ARGUMENTS: Returns the beginning of the next token
  76  */
  77 {
  78    PWSTR string;
  79    PWSTR sep;
  80    PWSTR start;
  81
  82    if (_string!=NULL)
  83      {
  84         string = _string->Buffer;
  85      }
  86    else
  87      {
  88         string = *temp;
  89      }
  90
  91    start = string;
  92
  93    while ((*string)!=0)
  94      {
  95         sep = _sep;
  96         while ((*sep)!=0)
  97           {
  98              if ((*string)==(*sep))
  99                {
 100                   *string=0;
 101                   *temp=string+1;
 102                   return(start);
 103                }
 104              sep++;
 105           }
 106         string++;
 107      }
 108    *temp=NULL;
 109    return(start);
 110 }