X-Git-Url: https://pd.if.org/git/?p=pdclib;a=blobdiff_plain;f=functions%2Fstring%2Fstrtok.c;h=3c427c549c9ea0b87e6851a7862f3c77a78b7e8d;hp=1e588e84bb1e52d9390c83bab8945eec82ca5b44;hb=da0f3f353d417fed71f358a48d5d5394145e460d;hpb=34893ecc2200dc7017c36a54cb6c5f4c2378b5ec

diff --git a/functions/string/strtok.c b/functions/string/strtok.c
index 1e588e8..3c427c5 100644
--- a/functions/string/strtok.c
+++ b/functions/string/strtok.c
@@ -1,8 +1,105 @@
-// ----------------------------------------------------------------------------
-// $Id$
-// ----------------------------------------------------------------------------
-// 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 */ };
+/* 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 <string.h>
+
+#ifndef REGTEST
+
+char * strtok( char * _PDCLIB_restrict s1, const char * _PDCLIB_restrict s2 )
+{
+    static char * tmp = NULL;
+    const char * p = s2;
+
+    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 */
+    tmp = NULL;
+    return s1;
+}
+
+#endif
+
+#ifdef TEST
+#include "_PDCLIB_test.h"
+
+int main( void )
+{
+    char s[] = "_a_bc__d_";
+    TESTCASE( strtok( s, "_" ) == &s[1] );
+    TESTCASE( s[1] == 'a' );
+    TESTCASE( s[2] == '\0' );
+    TESTCASE( strtok( NULL, "_" ) == &s[3] );
+    TESTCASE( s[3] == 'b' );
+    TESTCASE( s[4] == 'c' );
+    TESTCASE( s[5] == '\0' );
+    TESTCASE( strtok( NULL, "_" ) == &s[7] );
+    TESTCASE( s[6] == '_' );
+    TESTCASE( s[7] == 'd' );
+    TESTCASE( s[8] == '\0' );
+    TESTCASE( strtok( NULL, "_" ) == NULL );
+    strcpy( s, "ab_cd" );
+    TESTCASE( strtok( s, "_" ) == &s[0] );
+    TESTCASE( s[0] == 'a' );
+    TESTCASE( s[1] == 'b' );
+    TESTCASE( s[2] == '\0' );
+    TESTCASE( strtok( NULL, "_" ) == &s[3] );
+    TESTCASE( s[3] == 'c' );
+    TESTCASE( s[4] == 'd' );
+    TESTCASE( s[5] == '\0' );
+    TESTCASE( strtok( NULL, "_" ) == NULL );
+    return TEST_RESULTS;
+}
+#endif