From f653398c86a1c104f0992bd788dd4bb065449be4 Mon Sep 17 00:00:00 2001 From: André Goddard Rosa Date: Mon, 14 Dec 2009 18:01:04 -0800 Subject: string: factorize skip_spaces and export it to be generally available MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On the following sentence: while (*s && isspace(*s)) s++; If *s == 0, isspace() evaluates to ((_ctype[*s] & 0x20) != 0), which evaluates to ((0x08 & 0x20) != 0) which equals to 0 as well. If *s == 1, we depend on isspace() result anyway. In other words, "a char equals zero is never a space", so remove this check. Also, *s != 0 is most common case (non-null string). Fixed const return as noticed by Jan Engelhardt and James Bottomley. Fixed unnecessary extra cast on strstrip() as noticed by Jan Engelhardt. Signed-off-by: André Goddard Rosa Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/string.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) (limited to 'lib/string.c') diff --git a/lib/string.c b/lib/string.c index e96421ab9a9..3a912a4e9a6 100644 --- a/lib/string.c +++ b/lib/string.c @@ -337,6 +337,20 @@ char *strnchr(const char *s, size_t count, int c) EXPORT_SYMBOL(strnchr); #endif +/** + * skip_spaces - Removes leading whitespace from @s. + * @s: The string to be stripped. + * + * Returns a pointer to the first non-whitespace character in @s. + */ +char *skip_spaces(const char *str) +{ + while (isspace(*str)) + ++str; + return (char *)str; +} +EXPORT_SYMBOL(skip_spaces); + /** * strstrip - Removes leading and trailing whitespace from @s. * @s: The string to be stripped. @@ -360,10 +374,7 @@ char *strstrip(char *s) end--; *(end + 1) = '\0'; - while (*s && isspace(*s)) - s++; - - return s; + return skip_spaces(s); } EXPORT_SYMBOL(strstrip); -- cgit v1.2.3-70-g09d2 From 84c95c9acf088c99d8793d78036b67faa5d0b851 Mon Sep 17 00:00:00 2001 From: André Goddard Rosa Date: Mon, 14 Dec 2009 18:01:04 -0800 Subject: string: on strstrip(), first remove leading spaces before running over str MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit ... so that strlen() iterates over a smaller string comprising of the remaining characters only. Signed-off-by: André Goddard Rosa Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/string.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'lib/string.c') diff --git a/lib/string.c b/lib/string.c index 3a912a4e9a6..765566a6a08 100644 --- a/lib/string.c +++ b/lib/string.c @@ -364,8 +364,8 @@ char *strstrip(char *s) size_t size; char *end; + s = skip_spaces(s); size = strlen(s); - if (!size) return s; @@ -374,7 +374,7 @@ char *strstrip(char *s) end--; *(end + 1) = '\0'; - return skip_spaces(s); + return s; } EXPORT_SYMBOL(strstrip); -- cgit v1.2.3-70-g09d2 From ca54cb8c9eb38095dc420b73c6380ce1dbeb10fa Mon Sep 17 00:00:00 2001 From: KOSAKI Motohiro Date: Mon, 14 Dec 2009 18:01:15 -0800 Subject: Subject: Re: [PATCH] strstrip incorrectly marked __must_check Recently, We marked strstrip() as must_check. because it was frequently misused and it should be checked. However, we found one exception. scsi/ipr.c intentionally ignore return value of strstrip. Because it wishes to keep the whitespace at the beginning. Thus we need to keep with and without checked whitespace trim function. This patch adds a new strim() and changes ipr.c to use it. [akpm@linux-foundation.org: coding-style fixes] Suggested-by: Alan Cox Signed-off-by: KOSAKI Motohiro Cc: James Bottomley Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/scsi/ipr.c | 4 ++-- include/linux/string.h | 9 ++++++++- lib/string.c | 6 +++--- 3 files changed, 13 insertions(+), 6 deletions(-) (limited to 'lib/string.c') diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c index 206c2fa8c1b..8643f508936 100644 --- a/drivers/scsi/ipr.c +++ b/drivers/scsi/ipr.c @@ -1333,7 +1333,7 @@ static void ipr_log_enhanced_dual_ioa_error(struct ipr_ioa_cfg *ioa_cfg, error = &hostrcb->hcam.u.error.u.type_17_error; error->failure_reason[sizeof(error->failure_reason) - 1] = '\0'; - strstrip(error->failure_reason); + strim(error->failure_reason); ipr_hcam_err(hostrcb, "%s [PRC: %08X]\n", error->failure_reason, be32_to_cpu(hostrcb->hcam.u.error.prc)); @@ -1359,7 +1359,7 @@ static void ipr_log_dual_ioa_error(struct ipr_ioa_cfg *ioa_cfg, error = &hostrcb->hcam.u.error.u.type_07_error; error->failure_reason[sizeof(error->failure_reason) - 1] = '\0'; - strstrip(error->failure_reason); + strim(error->failure_reason); ipr_hcam_err(hostrcb, "%s [PRC: %08X]\n", error->failure_reason, be32_to_cpu(hostrcb->hcam.u.error.prc)); diff --git a/include/linux/string.h b/include/linux/string.h index 168dad11ae0..651839a2a75 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -63,7 +63,14 @@ extern char * strnchr(const char *, size_t, int); extern char * strrchr(const char *,int); #endif extern char * __must_check skip_spaces(const char *); -extern char * __must_check strstrip(char *); + +extern char *strim(char *); + +static inline __must_check char *strstrip(char *str) +{ + return strim(str); +} + #ifndef __HAVE_ARCH_STRSTR extern char * strstr(const char *,const char *); #endif diff --git a/lib/string.c b/lib/string.c index 765566a6a08..afce96af3af 100644 --- a/lib/string.c +++ b/lib/string.c @@ -352,14 +352,14 @@ char *skip_spaces(const char *str) EXPORT_SYMBOL(skip_spaces); /** - * strstrip - Removes leading and trailing whitespace from @s. + * strim - Removes leading and trailing whitespace from @s. * @s: The string to be stripped. * * Note that the first trailing whitespace is replaced with a %NUL-terminator * in the given string @s. Returns a pointer to the first non-whitespace * character in @s. */ -char *strstrip(char *s) +char *strim(char *s) { size_t size; char *end; @@ -376,7 +376,7 @@ char *strstrip(char *s) return s; } -EXPORT_SYMBOL(strstrip); +EXPORT_SYMBOL(strim); #ifndef __HAVE_ARCH_STRLEN /** -- cgit v1.2.3-70-g09d2 From a6cd13f3c98d1d16213e3b61054b9c209d93f877 Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Mon, 21 Dec 2009 14:37:22 -0800 Subject: lib/string.c: fix kernel-doc warnings Fix kernel-doc warnings (@arg name) in string.c::skip_spaces(). Warning(lib/string.c:347): No description found for parameter 'str' Warning(lib/string.c:347): Excess function parameter 's' description in 'skip_spaces' Signed-off-by: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/string.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'lib/string.c') diff --git a/lib/string.c b/lib/string.c index afce96af3af..9f75b4ec50b 100644 --- a/lib/string.c +++ b/lib/string.c @@ -338,10 +338,10 @@ EXPORT_SYMBOL(strnchr); #endif /** - * skip_spaces - Removes leading whitespace from @s. - * @s: The string to be stripped. + * skip_spaces - Removes leading whitespace from @str. + * @str: The string to be stripped. * - * Returns a pointer to the first non-whitespace character in @s. + * Returns a pointer to the first non-whitespace character in @str. */ char *skip_spaces(const char *str) { -- cgit v1.2.3-70-g09d2 From d5f1fb53353edc38da326445267c1df0c9676df2 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Thu, 14 Jan 2010 10:53:55 +0800 Subject: lib: Introduce strnstr() It differs strstr() in that it limits the length to be searched in the first string. Signed-off-by: Li Zefan LKML-Reference: <4B4E8743.6030805@cn.fujitsu.com> Acked-by: Frederic Weisbecker Signed-off-by: Steven Rostedt --- include/linux/string.h | 5 ++++- lib/string.c | 27 ++++++++++++++++++++++++++- 2 files changed, 30 insertions(+), 2 deletions(-) (limited to 'lib/string.c') diff --git a/include/linux/string.h b/include/linux/string.h index 651839a2a75..a716ee2a8ad 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -72,7 +72,10 @@ static inline __must_check char *strstrip(char *str) } #ifndef __HAVE_ARCH_STRSTR -extern char * strstr(const char *,const char *); +extern char * strstr(const char *, const char *); +#endif +#ifndef __HAVE_ARCH_STRNSTR +extern char * strnstr(const char *, const char *, size_t); #endif #ifndef __HAVE_ARCH_STRLEN extern __kernel_size_t strlen(const char *); diff --git a/lib/string.c b/lib/string.c index 9f75b4ec50b..a1cdcfcc42d 100644 --- a/lib/string.c +++ b/lib/string.c @@ -667,7 +667,7 @@ EXPORT_SYMBOL(memscan); */ char *strstr(const char *s1, const char *s2) { - int l1, l2; + size_t l1, l2; l2 = strlen(s2); if (!l2) @@ -684,6 +684,31 @@ char *strstr(const char *s1, const char *s2) EXPORT_SYMBOL(strstr); #endif +#ifndef __HAVE_ARCH_STRNSTR +/** + * strnstr - Find the first substring in a length-limited string + * @s1: The string to be searched + * @s2: The string to search for + * @len: the maximum number of characters to search + */ +char *strnstr(const char *s1, const char *s2, size_t len) +{ + size_t l1 = len, l2; + + l2 = strlen(s2); + if (!l2) + return (char *)s1; + while (l1 >= l2) { + l1--; + if (!memcmp(s1, s2, l2)) + return (char *)s1; + s1++; + } + return NULL; +} +EXPORT_SYMBOL(strnstr); +#endif + #ifndef __HAVE_ARCH_MEMCHR /** * memchr - Find a character in an area of memory. -- cgit v1.2.3-70-g09d2