Messages in this thread Patch in this message |  | | From | Rasmus Villemoes <> | Subject | [PATCH v2 1/8] lib: string: Introduce strreplace | Date | Tue, 9 Jun 2015 01:26:49 +0200 |
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Strings are sometimes sanitized by replacing a certain character (often '/') by another (often '!'). In a few places, this is done the same way Schlemiel the Painter would do it. Others are slightly smarter but still do multiple strchr() calls. Introduce strreplace() to do this using a single function call and a single pass over the string.
One would expect the return value to be one of three things: void, s, or the number of replacements made. I chose the fourth, returning a pointer to the end of the string. This is more likely to be useful (for example allowing the caller to avoid a strlen call).
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> --- v2: spello fixed, parameters renamed 'old' and 'new' (just so the kernel doc aligns nicely, and because that's what python -c 'help(str.replace)' uses). Still EXPORT_SYMBOL, not inline (tried it, caused more bloat), still called strreplace.
include/linux/string.h | 1 + lib/string.c | 17 +++++++++++++++++ 2 files changed, 18 insertions(+)
diff --git a/include/linux/string.h b/include/linux/string.h index e40099e585c9..a8d90db9c4b0 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -111,6 +111,7 @@ extern int memcmp(const void *,const void *,__kernel_size_t); extern void * memchr(const void *,int,__kernel_size_t); #endif void *memchr_inv(const void *s, int c, size_t n); +char *strreplace(char *s, char old, char new); extern void kfree_const(const void *x); diff --git a/lib/string.c b/lib/string.c index bb3d4b6993c4..13d1e84ddb80 100644 --- a/lib/string.c +++ b/lib/string.c @@ -849,3 +849,20 @@ void *memchr_inv(const void *start, int c, size_t bytes) return check_bytes8(start, value, bytes % 8); } EXPORT_SYMBOL(memchr_inv); + +/** + * strreplace - Replace all occurrences of character in string. + * @s: The string to operate on. + * @old: The character being replaced. + * @new: The character @old is replaced with. + * + * Returns pointer to the nul byte at the end of @s. + */ +char *strreplace(char *s, char old, char new) +{ + for (; *s; ++s) + if (*s == old) + *s = new; + return s; +} +EXPORT_SYMBOL(strreplace); -- 2.1.3
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