tools include: Adopt strstarts() from the kernel

Replacing prefixcmp(), same purpose, inverted result, so standardize on
the kernel variant, to reduce silly differences among tools/ and the
kernel sources, making it easier for people to work in both codebases.

And then doing:

	if (strstarts(option, "no-"))

Looks clearer than doing:

	if (!prefixcmp(option, "no-"))

To figure out if option starts witn "no-".

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-kaei42gi7lpa8subwtv7eug8@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 10 insertions, 2 deletions

diff --git a/tools/include/linux/string.h b/tools/include/linux/string.h
index d62b56cf8c12..a30fad536f52 100644
--- a/tools/include/linux/string.h
+++ b/tools/include/linux/string.h
@@ -1,8 +1,8 @@
 #ifndef _TOOLS_LINUX_STRING_H_
 #define _TOOLS_LINUX_STRING_H_
 
-
 #include <linux/types.h>        /* for size_t */
+#include <string.h>
 
 void *memdup(const void *src, size_t len);
 
@@ -18,6 +18,14 @@ extern size_t strlcpy(char *dest, const char *src, size_t size);
 
 char *str_error_r(int errnum, char *buf, size_t buflen);
 
-int prefixcmp(const char *str, const char *prefix);
+/**
+ * strstarts - does @str start with @prefix?
+ * @str: string to examine
+ * @prefix: prefix to look for.
+ */
+static inline bool strstarts(const char *str, const char *prefix)
+{
+        return strncmp(str, prefix, strlen(prefix)) == 0;
+}
 
 #endif /* _LINUX_STRING_H_ */