From d0f1fed29e6e73d9d17f4c91a5896a4ce3938d45 Mon Sep 17 00:00:00 2001 From: Jonathan Cameron Date: Tue, 19 Apr 2011 12:43:45 +0100 Subject: Add a strtobool function matching semantics of existing in kernel equivalents This is a rename of the usr_strtobool proposal, which was a renamed, relocated and fixed version of previous kstrtobool RFC Signed-off-by: Jonathan Cameron Signed-off-by: Rusty Russell --- include/linux/string.h | 1 + lib/string.c | 29 +++++++++++++++++++++++++++++ 2 files changed, 30 insertions(+) diff --git a/include/linux/string.h b/include/linux/string.h index a716ee2a8ad..a176db2f2c8 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -123,6 +123,7 @@ extern char **argv_split(gfp_t gfp, const char *str, int *argcp); extern void argv_free(char **argv); extern bool sysfs_streq(const char *s1, const char *s2); +extern int strtobool(const char *s, bool *res); #ifdef CONFIG_BINARY_PRINTF int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args); diff --git a/lib/string.c b/lib/string.c index f71bead1be3..01fad9b203e 100644 --- a/lib/string.c +++ b/lib/string.c @@ -535,6 +535,35 @@ bool sysfs_streq(const char *s1, const char *s2) } EXPORT_SYMBOL(sysfs_streq); +/** + * strtobool - convert common user inputs into boolean values + * @s: input string + * @res: result + * + * This routine returns 0 iff the first character is one of 'Yy1Nn0'. + * Otherwise it will return -EINVAL. Value pointed to by res is + * updated upon finding a match. + */ +int strtobool(const char *s, bool *res) +{ + switch (s[0]) { + case 'y': + case 'Y': + case '1': + *res = true; + break; + case 'n': + case 'N': + case '0': + *res = false; + break; + default: + return -EINVAL; + } + return 0; +} +EXPORT_SYMBOL(strtobool); + #ifndef __HAVE_ARCH_MEMSET /** * memset - Fill a region of memory with the given value -- cgit v1.2.3