-// ----------------------------------------------------------------------------
-// $Id$
-// ----------------------------------------------------------------------------
-// Public Domain C Library - http://pdclib.sourceforge.net
-// This code is Public Domain. Use, modify, and redistribute at will.
-// ----------------------------------------------------------------------------
-
-char * strtok( char * restrict s1, const char * restrict s2 ) { /* TODO */ };
+/* $Id$ */
+
+/* Release $Name$ */
+
+/* strtok( char *, const char * )
+
+ This file is part of the Public Domain C Library (PDCLib).
+ Permission is granted to use, modify, and / or redistribute at will.
+*/
+
+#include <_PDCLIB_aux.h>
+#include <string.h>
+
+char * strtok( char * _PDCLIB_restrict s1, const char * _PDCLIB_restrict s2 )
+{
+ static char * tmp = NULL;
+ const char * p = s2;
+ size_t len;
+
+ if ( s1 != NULL )
+ {
+ /* new string */
+ tmp = s1;
+ }
+ else
+ {
+ /* old string continued */
+ if ( tmp == NULL )
+ {
+ /* No old string, no new string, nothing to do */
+ return NULL;
+ }
+ s1 = tmp;
+ }
+
+ /* skipping leading s2 characters */
+ while ( *p && *s1 )
+ {
+ if ( *s1 == *p )
+ {
+ /* found seperator; skip and start over */
+ ++s1;
+ p = s2;
+ continue;
+ }
+ ++p;
+ }
+
+ if ( ! *s1 )
+ {
+ /* no more to parse */
+ return ( tmp = NULL );
+ }
+
+ /* skipping non-s2 characters */
+ tmp = s1;
+ while ( *tmp )
+ {
+ p = s2;
+ while ( *p )
+ {
+ if ( *tmp == *p++ )
+ {
+ /* found seperator; overwrite with '\0', position tmp, return */
+ *tmp++ = '\0';
+ return s1;
+ }
+ }
+ ++tmp;
+ }
+
+ /* parsed to end of string */
+ return ( tmp = NULL );
+}
+
+#warning Test driver missing.
+
+#ifdef TEST
+int main()
+{
+ return 0;
+}
+#endif