string: Introduce strtobool

We have at least two places which convert a string to a boolean type,
so create a common function for this. strtobool treats

- any positive (nonzero) number as true
- "0" as false
- "true" (case insensitive) as true
- "false" (case insensitive) as false

Every other value results in an error and the input *val is not
modified. The caller is expected to initialize *val with the correct
default before calling strtobool.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/string.h b/include/string.h
index a833da131b..0c557d6f15 100644
--- a/include/string.h
+++ b/include/string.h
@@ -4,5 +4,6 @@
 #include <linux/string.h>
 
 void *memdup(const void *, size_t);
+int strtobool(const char *str, int *val);
 
 #endif /* __STRING_H */