tools lib string: Adopt prefixcmp() from perf and subcmd

Both had copies originating from git.git, move those to
tools/lib/string.c, getting both tools/lib/subcmd/ and tools/perf/ to
use it.

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: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-uidwtticro1qhttzd2rkrkg1@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

4 files changed, 11 insertions, 9 deletions

diff --git a/tools/lib/string.c b/tools/lib/string.c
index bd239bc1d557..8e678af1c6ee 100644
--- a/tools/lib/string.c
+++ b/tools/lib/string.c
@@ -87,3 +87,12 @@ size_t __weak strlcpy(char *dest, const char *src, size_t size)
         }
         return ret;
 }
+
+int prefixcmp(const char *str, const char *prefix)
+{
+        for (; ; str++, prefix++)
+                if (!*prefix)
+                        return 0;
+                else if (*str != *prefix)
+                        return (unsigned char)*prefix - (unsigned char)*str;
+}
diff --git a/tools/lib/subcmd/help.c b/tools/lib/subcmd/help.c
index e228c3cb3716..ba970a73d053 100644
--- a/tools/lib/subcmd/help.c
+++ b/tools/lib/subcmd/help.c
@@ -1,6 +1,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <linux/string.h>
 #include <termios.h>
 #include <sys/ioctl.h>
 #include <sys/types.h>
diff --git a/tools/lib/subcmd/parse-options.c b/tools/lib/subcmd/parse-options.c
index 6bc24025d054..359bfa77f39c 100644
--- a/tools/lib/subcmd/parse-options.c
+++ b/tools/lib/subcmd/parse-options.c
@@ -1,4 +1,5 @@
 #include <linux/compiler.h>
+#include <linux/string.h>
 #include <linux/types.h>
 #include <stdio.h>
 #include <stdlib.h>
diff --git a/tools/lib/subcmd/subcmd-util.h b/tools/lib/subcmd/subcmd-util.h
index fc2e45d8aaf1..8fa5f036eff0 100644
--- a/tools/lib/subcmd/subcmd-util.h
+++ b/tools/lib/subcmd/subcmd-util.h
@@ -79,13 +79,4 @@ static inline void astrcat(char **out, const char *add)
         free(tmp);
 }
 
-static inline int prefixcmp(const char *str, const char *prefix)
-{
-        for (; ; str++, prefix++)
-                if (!*prefix)
-                        return 0;
-                else if (*str != *prefix)
-                        return (unsigned char)*prefix - (unsigned char)*str;
-}
-
 #endif /* __SUBCMD_UTIL_H */