From c9f59a78c0016b37730cec831e1eec139ca4a561 Mon Sep 17 00:00:00 2001

From: Lennart Poettering <lennart@poettering.net>

Date: Wed, 25 Sep 2013 20:58:23 +0200

Subject: [PATCH] util: add macro for iterating through all prefixes of a path

Syntactic sugar in a macro PATH_FOREACH_PREFIX.

---

 src/shared/cgroup-util.c  | 26 ++++----------------------

 src/shared/path-util.h    |  3 +++

 src/test/test-path-util.c | 27 +++++++++++++++++++++++++++

 3 files changed, 34 insertions(+), 22 deletions(-)

diff --git a/src/shared/cgroup-util.c b/src/shared/cgroup-util.c

index 2e630d4..dc0fe85 100644

--- a/src/shared/cgroup-util.c

+++ b/src/shared/cgroup-util.c

@@ -456,23 +456,14 @@ int cg_migrate_recursive_fallback(

                 /* This didn't work? Then let's try all prefixes of the destination */

-                strcpy(prefix, pto);

-                for (;;) {

-                        char *slash;

-

-                        slash = strrchr(prefix, '/');

-                        if (!slash)

-                                break;

-

-                        *slash = 0;

-

+                PATH_FOREACH_PREFIX(prefix, pto) {

                         r = cg_migrate_recursive(cfrom, pfrom, cto, prefix, ignore_self, rem);

                         if (r >= 0)

                                 break;

                 }

         }

-        return r;

+        return 0;

 }

 static const char *normalize_controller(const char *controller) {

@@ -661,23 +652,14 @@ int cg_attach_fallback(const char *controller, const char *path, pid_t pid) {

                 /* This didn't work? Then let's try all prefixes of

                  * the destination */

-                strcpy(prefix, path);

-                for (;;) {

-                        char *slash;

-

-                        slash = strrchr(prefix, '/');

-                        if (!slash)

-                                break;

-

-                        *slash = 0;

-

+                PATH_FOREACH_PREFIX(prefix, path) {

                         r = cg_attach(controller, prefix, pid);

                         if (r >= 0)

                                 break;

                 }

         }

-        return r;

+        return 0;

 }

 int cg_set_group_access(

diff --git a/src/shared/path-util.h b/src/shared/path-util.h

index 9452931..03f2cf2 100644

--- a/src/shared/path-util.h

+++ b/src/shared/path-util.h

@@ -51,3 +51,6 @@ int path_is_read_only_fs(const char *path);

 int path_is_os_tree(const char *path);

 int find_binary(const char *name, char **filename);

+

+#define PATH_FOREACH_PREFIX(prefix, path) \

+        for (char *_slash = strrchr(path_kill_slashes(strcpy(prefix, path)), '/'); _slash && !(*_slash = 0); _slash = strrchr((prefix), '/'))

diff --git a/src/test/test-path-util.c b/src/test/test-path-util.c

index b0aeb11..e303e48 100644

--- a/src/test/test-path-util.c

+++ b/src/test/test-path-util.c

@@ -106,8 +106,35 @@ static void test_find_binary(void) {

         assert(find_binary("xxxx-xxxx", &p) == -ENOENT);

 }

+static void test_prefixes(void) {

+        static const char* values[] = { "/a/b/c", "/a/b", "/a", "", NULL};

+        unsigned i = 0;

+        char s[PATH_MAX];

+

+        PATH_FOREACH_PREFIX(s, "/a/b/c/d") {

+                log_error("---%s---", s);

+                assert_se(streq(s, values[i++]));

+        }

+

+        assert_se(values[i] == NULL);

+

+        i = 0;

+        PATH_FOREACH_PREFIX(s, "////a////b////c///d///////")

+                assert_se(streq(s, values[i++]));

+

+        assert_se(values[i] == NULL);

+

+        PATH_FOREACH_PREFIX(s, "////")

+                assert_se(streq(s, ""));

+

+        PATH_FOREACH_PREFIX(s, "")

+                assert_not_reached("wut?");

+

+}

+

 int main(void) {

         test_path();

         test_find_binary();

+        test_prefixes();

         return 0;

 }