From 11d200e95f3e84c1102e4cc9863a3614fd41f3ad Mon Sep 17 00:00:00 2001 From: Grant Likely Date: Fri, 14 Mar 2014 17:00:14 +0000 Subject: 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 --- lib/string.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'lib/string.c') diff --git a/lib/string.c b/lib/string.c index 9b1f9062a20..e0c20eb362f 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 -- cgit v1.2.3-70-g09d2 From 0046dd9fed0c9313cbb4fb860324476cd298dc9f Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Wed, 4 Jun 2014 16:11:47 -0700 Subject: lib/string.c: use the name "C-string" in comments For strncpy() and friends the source string may or may not have an actual NUL character at the end. The documentation is confusing in this because it specifically mentions that you are passing a "NUL-terminated" string. Wikipedia says that "C-string" is an alternative name we can use instead. http://en.wikipedia.org/wiki/Null-terminated_string Signed-off-by: Dan Carpenter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/string.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'lib/string.c') diff --git a/lib/string.c b/lib/string.c index e0c20eb362f..992bf30af75 100644 --- a/lib/string.c +++ b/lib/string.c @@ -107,7 +107,7 @@ EXPORT_SYMBOL(strcpy); #ifndef __HAVE_ARCH_STRNCPY /** - * strncpy - Copy a length-limited, %NUL-terminated string + * strncpy - Copy a length-limited, C-string * @dest: Where to copy the string to * @src: Where to copy the string from * @count: The maximum number of bytes to copy @@ -136,7 +136,7 @@ EXPORT_SYMBOL(strncpy); #ifndef __HAVE_ARCH_STRLCPY /** - * strlcpy - Copy a %NUL terminated string into a sized buffer + * strlcpy - Copy a C-string into a sized buffer * @dest: Where to copy the string to * @src: Where to copy the string from * @size: size of destination buffer @@ -182,7 +182,7 @@ EXPORT_SYMBOL(strcat); #ifndef __HAVE_ARCH_STRNCAT /** - * strncat - Append a length-limited, %NUL-terminated string to another + * strncat - Append a length-limited, C-string to another * @dest: The string to be appended to * @src: The string to append to it * @count: The maximum numbers of bytes to copy @@ -211,7 +211,7 @@ EXPORT_SYMBOL(strncat); #ifndef __HAVE_ARCH_STRLCAT /** - * strlcat - Append a length-limited, %NUL-terminated string to another + * strlcat - Append a length-limited, C-string to another * @dest: The string to be appended to * @src: The string to append to it * @count: The size of the destination buffer. -- cgit v1.2.3-70-g09d2