lib/string.c: introduce strreplace()
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>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/string.h b/include/linux/string.h
index e40099e..a8d90db 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -111,6 +111,7 @@
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 bb3d4b6..13d1e84 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -849,3 +849,20 @@
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);