As the name shows, it checks if strings are equal in case insensitive
manner.
For example, drivers/infiniband/ulp/rtrs/rtrs-clt-sysfs.c uses
strncasecmp to check that the input via sysfs is "mi". But it would
work even-if the input is "min-wrongcommand".
I found some more cases using strncasecmp to check the entire string
such as rtrs-clt-sysfs.c does. drivers/pnp/interface.c checks
"disable" command with strncasecmp but it would also work if the
command is "disable-wrong".
Signed-off-by: Gioh Kim <gi-oh....@ionos.com>
---
include/linux/string.h | 1 +
lib/string.c | 36 ++++++++++++++++++++++++++++--------
2 files changed, 29 insertions(+), 8 deletions(-)
diff --git a/include/linux/string.h b/include/linux/string.h
index 4fcfb56abcf5..36d00ff8013e 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -184,6 +184,7 @@ 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 bool sysfs_streqcase(const char *s1, const char *s2);
extern int kstrtobool(const char *s, bool *res);
static inline int strtobool(const char *s, bool *res)
{
diff --git a/lib/string.c b/lib/string.c
index 7548eb715ddb..d0fb02efd5da 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -687,6 +687,17 @@ char *strsep(char **s, const char *ct)
EXPORT_SYMBOL(strsep);
#endif
+static inline bool __streq_terminal(const char *s1, const char *s2)
+{
+ if (*s1 == *s2)
+ return true;
+ if (!*s1 && *s2 == '\n' && !s2[1])
+ return true;
+ if (*s1 == '\n' && !s1[1] && !*s2)
+ return true;
+ return false;
+}
+
/**
* sysfs_streq - return true if strings are equal, modulo trailing newline
* @s1: one string
@@ -703,17 +714,26 @@ bool sysfs_streq(const char *s1, const char *s2)
s1++;
s2++;
}
-
- if (*s1 == *s2)
- return true;
- if (!*s1 && *s2 == '\n' && !s2[1])
- return true;
- if (*s1 == '\n' && !s1[1] && !*s2)
- return true;
- return false;
+ return __streq_terminal(s1, s2);
}
EXPORT_SYMBOL(sysfs_streq);
+/**
+ * sysfs_streqcase - same to sysfs_streq and case insensitive
+ * @s1: one string
+ * @s2: another string
+ *
+ */
+bool sysfs_streqcase(const char *s1, const char *s2)
+{
+ while (*s1 && tolower(*s1) == tolower(*s2)) {
+ s1++;
+ s2++;
+ }
+ return __streq_terminal(s1, s2);
+}
+EXPORT_SYMBOL(sysfs_streqcase);
+
/**
* match_string - matches given string in an array
* @array: array of strings
--
2.25.1
