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authorGrant Likely <grant.likely@linaro.org>2014-03-14 17:00:14 +0000
committerGrant Likely <grant.likely@linaro.org>2014-05-23 11:23:27 +0900
commit11d200e95f3e84c1102e4cc9863a3614fd41f3ad (patch)
tree2d10860071a5c0d9a39754562ed33e1014faa91e
parentb44aa25d20e2ef6b824901cbc50a281791f3b421 (diff)
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>
-rw-r--r--include/linux/string.h3
-rw-r--r--lib/string.c18
2 files changed, 21 insertions, 0 deletions
diff --git a/include/linux/string.h b/include/linux/string.h
index ac889c5ea11b..d36977e029af 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -52,6 +52,9 @@ extern int strncasecmp(const char *s1, const char *s2, size_t n);
#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
diff --git a/lib/string.c b/lib/string.c
index 9b1f9062a202..e0c20eb362f0 100644
--- 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