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Commit 11d200e9 authored by Grant Likely's avatar Grant Likely
Browse files

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: default avatarGrant Likely <grant.likely@linaro.org>
parent b44aa25d

include/linux/string.h

+3 −0
Original line number Diff line number Diff line
@@ -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

lib/string.c

+18 −0
Original line number Diff line number Diff line
@@ -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