[PATCH 24/44] Add a strtobool function matching semantics of existing in kernel equivalents

Greg Kroah-Hartman
2011-05-20T00:11:53Z

From: Jonathan Cameron <jic23@cam.ac.uk>

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 <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
include/linux/string.h | 1 +
lib/string.c | 29 +++++++++++++++++++++++++++++
2 files changed, 30 insertions(+), 0 deletions(-)

diff --git a/include/linux/string.h b/include/linux/string.h
index a716ee2..a176db2 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 f71bead..01fad9b 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
--
1.7.4.2