1 files changed, 88 insertions, 0 deletions
diff --git a/firmware/common/strptokspn.c b/firmware/common/strptokspn.c
new file mode 100644
index 0000000000..f4b92c0712
--- /dev/null
+++ b/firmware/common/strptokspn.c
@@ -0,0 +1,88 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2022 by William WIlgus
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied. *
+ ****************************************************************************/
+
+#include "config.h"
+
+#include <stddef.h>
+#include <string.h>
+#include "strtok_r.h"
+/* strptokspn_r is a custom implementation of strtok_r that does NOT modify 
+ *  the source string.
+ *
+ * strptokspn_r reads ptr as a series of zero or more tokens,
+ *  and sep as delimiters of the tokens
+ * The tokens can be separated by one or more of the delimiters
+ * first call searches for the first token skipping over any leading delimiters.
+ * Returns pointer to first token
+ * Pointer *len contains the span to the first delimeter
+ *  (this would be the resulting strlen had token actually been NULL terminated)
+ * Pointer **end contains pointer to first character after the last delimeter
+ *
+ * When strptokspn_r is called with a ptr == NULL, the next token is read from
+ * Pointer **end
+ *
+ * Note the returned token is NOT NULL terminated by the function as in strtok_r
+ * However the caller can use ret[len+1] = '\0'; to emulate a call to strtok_r
+*/
+
+const char *strptokspn_r(const char *ptr, const char *sep, size_t *len, const char **end)
+{
+    *len = 0;
+    if (!ptr)
+        /* we got NULL input so then we get our last position instead */
+        ptr = *end;
+
+    /* pass all letters that are including in the separator string */
+    while (*ptr && strchr(sep, *ptr))
+        ++ptr;
+
+    if (*ptr) {
+        /* so this is where the next piece of string starts */
+        const char *start = ptr;
+
+        /* set the end pointer to the first byte after the start */
+        *end = start + 1;
+
+        /* scan through the string to find where it ends, it ends on a
+           null byte or a character that exists in the separator string */
+        while (**end && !strchr(sep, **end))
+            ++*end;
+        *len  = (*end - start) - 1; /* this would be the string len if there actually was a NULL */
+        if (**end) { /* the end is not a null byte */
+            ++*end;  /* advance last pointer to beyond the match */
+        }
+
+        return start; /* return the position where the string starts */
+    }
+
+    /* we ended up on a null byte, there are no more strings to find! */
+    return NULL;
+}
+
+#if !defined(HAVE_STRTOK_R)
+char * strtok_r(char *ptr, const char *sep, char **end)
+{
+    size_t len;
+    char * ret = (char*) strptokspn_r((const char*)ptr, sep, &len, (const char**) end);
+    if (ret)
+        ret[len + 1] = '\0';
+    return ret;
+}
+#endif