make splash split on control characters

splits on spaces also considers \r\n\f\v\t as mandatory breaks

I'm still working on the strptokspn function
my goal is to use it directly rather than storing the matched char
and modifying the source string with \0 in order to tokenize the output
--Done

Change-Id: I7f378b5b9c4df8f10899b9a55a98950afb3931dc

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