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From 11d200e95f3e84c1102e4cc9863a3614fd41f3ad Mon Sep 17 00:00:00 2001
From: Grant Likely <grant.likely@linaro.org>
Date: Fri, 14 Mar 2014 17:00:14 +0000
Subject: [PATCH] lib: add glibc style strchrnul() variant
The strchrnul() variant helpfully returns a the end of the string
instead of a NULL if the requested character is not found. This can
simplify string parsing code since it doesn't need to expicitly check
for a NULL return. If a valid string pointer is passed in, then a valid
null terminated string will always come back out.
Signed-off-by: Grant Likely <grant.likely@linaro.org>
---
include/linux/string.h | 3 +++
lib/string.c | 18 ++++++++++++++++++
2 files changed, 21 insertions(+)
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -52,6 +52,9 @@ extern int strncasecmp(const char *s1, c
#ifndef __HAVE_ARCH_STRCHR
extern char * strchr(const char *,int);
#endif
+#ifndef __HAVE_ARCH_STRCHRNUL
+extern char * strchrnul(const char *,int);
+#endif
#ifndef __HAVE_ARCH_STRNCHR
extern char * strnchr(const char *, size_t, int);
#endif
--- a/lib/string.c
+++ b/lib/string.c
@@ -301,6 +301,24 @@ char *strchr(const char *s, int c)
EXPORT_SYMBOL(strchr);
#endif
+#ifndef __HAVE_ARCH_STRCHRNUL
+/**
+ * strchrnul - Find and return a character in a string, or end of string
+ * @s: The string to be searched
+ * @c: The character to search for
+ *
+ * Returns pointer to first occurrence of 'c' in s. If c is not found, then
+ * return a pointer to the null byte at the end of s.
+ */
+char *strchrnul(const char *s, int c)
+{
+ while (*s && *s != (char)c)
+ s++;
+ return (char *)s;
+}
+EXPORT_SYMBOL(strchrnul);
+#endif
+
#ifndef __HAVE_ARCH_STRRCHR
/**
* strrchr - Find the last occurrence of a character in a string
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