From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Thu, 31 May 2018 14:39:31 +0000 (+0900)
Subject: path-util: introduce path_simplify()
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=7851cfbcac23fc8c8e167c3691a1f63fd277fa1a;p=elogind.git

path-util: introduce path_simplify()

The function is similar to path_kill_slashes() but also removes
initial './', trailing '/.', and '/./' in the path.
When the second argument of path_simplify() is false, then it
behaves as the same as path_kill_slashes(). Hence, this also
replaces path_kill_slashes() with path_simplify().
---

diff --git a/src/basic/cgroup-util.c b/src/basic/cgroup-util.c
index 0570e9abf..63117afb1 100644
--- a/src/basic/cgroup-util.c
+++ b/src/basic/cgroup-util.c
@@ -634,7 +634,7 @@ int cg_get_path(const char *controller, const char *path, const char *suffix, ch
                 if (!t)
                         return -ENOMEM;
 
-                *fs = path_kill_slashes(t);
+                *fs = path_simplify(t, false);
                 return 0;
         }
 
@@ -651,7 +651,7 @@ int cg_get_path(const char *controller, const char *path, const char *suffix, ch
         if (r < 0)
                 return r;
 
-        path_kill_slashes(*fs);
+        path_simplify(*fs, false);
         return 0;
 }
 
@@ -1267,7 +1267,7 @@ int cg_split_spec(const char *spec, char **controller, char **path) {
                         if (!t)
                                 return -ENOMEM;
 
-                        *path = path_kill_slashes(t);
+                        *path = path_simplify(t, false);
                 }
 
                 if (controller)
@@ -1319,7 +1319,7 @@ int cg_split_spec(const char *spec, char **controller, char **path) {
                         return -EINVAL;
                 }
 
-                path_kill_slashes(u);
+                path_simplify(u, false);
         }
 
         if (controller)
@@ -1350,7 +1350,7 @@ int cg_mangle_path(const char *path, char **result) {
                 if (!t)
                         return -ENOMEM;
 
-                *result = path_kill_slashes(t);
+                *result = path_simplify(t, false);
                 return 0;
         }
 
diff --git a/src/basic/fileio.c b/src/basic/fileio.c
index 859298ff0..245402f6d 100644
--- a/src/basic/fileio.c
+++ b/src/basic/fileio.c
@@ -1240,7 +1240,7 @@ int tempfn_xxxxxx(const char *p, const char *extra, char **ret) {
 
         strcpy(stpcpy(stpcpy(stpcpy(mempcpy(t, p, fn - p), ".#"), extra), fn), "XXXXXX");
 
-        *ret = path_kill_slashes(t);
+        *ret = path_simplify(t, false);
         return 0;
 }
 
@@ -1281,7 +1281,7 @@ int tempfn_random(const char *p, const char *extra, char **ret) {
 
         *x = 0;
 
-        *ret = path_kill_slashes(t);
+        *ret = path_simplify(t, false);
         return 0;
 }
 
@@ -1322,7 +1322,7 @@ int tempfn_random_child(const char *p, const char *extra, char **ret) {
 
         *x = 0;
 
-        *ret = path_kill_slashes(t);
+        *ret = path_simplify(t, false);
         return 0;
 }
 
diff --git a/src/basic/mount-util.c b/src/basic/mount-util.c
index 9d1f34e08..76c0969d4 100644
--- a/src/basic/mount-util.c
+++ b/src/basic/mount-util.c
@@ -414,7 +414,7 @@ int bind_remount_recursive_with_mountinfo(const char *prefix, bool ro, char **bl
         if (!cleaned)
                 return -ENOMEM;
 
-        path_kill_slashes(cleaned);
+        path_simplify(cleaned, false);
 
         done = set_new(&path_hash_ops);
         if (!done)
diff --git a/src/basic/path-util.c b/src/basic/path-util.c
index 957c13bb3..eb91adf5b 100644
--- a/src/basic/path-util.c
+++ b/src/basic/path-util.c
@@ -162,7 +162,7 @@ int path_make_relative(const char *from_dir, const char *to_path, char **_r) {
                         if (!r)
                                 return -ENOMEM;
 
-                        path_kill_slashes(r);
+                        path_simplify(r, false);
 
                         *_r = r;
                         return 0;
@@ -217,7 +217,7 @@ int path_make_relative(const char *from_dir, const char *to_path, char **_r) {
                 p = mempcpy(p, "../", 3);
 
         strcpy(p, to_path);
-        path_kill_slashes(r);
+        path_simplify(r, false);
 
         *_r = r;
         return 0;
@@ -238,7 +238,7 @@ int path_strv_make_absolute_cwd(char **l) {
                 if (r < 0)
                         return r;
 
-                path_kill_slashes(t);
+                path_simplify(t, false);
                 free_and_replace(*s, t);
         }
 
@@ -339,17 +339,30 @@ char **path_strv_resolve_uniq(char **l, const char *root) {
         return strv_uniq(l);
 }
 
-char *path_kill_slashes(char *path) {
+char *path_simplify(char *path, bool kill_dots) {
         char *f, *t;
-        bool slash = false;
+        bool slash = false, ignore_slash = false, absolute;
 
-        /* Removes redundant inner and trailing slashes. Modifies the
-         * passed string in-place.
+        assert(path);
+
+        /* Removes redundant inner and trailing slashes. Also removes unnecessary dots
+         * if kill_dots is true. Modifies the passed string in-place.
          *
-         * ///foo///bar/ becomes /foo/bar
+         * ///foo//./bar/.   becomes /foo/./bar/.  (if kill_dots is false)
+         * ///foo//./bar/.   becomes /foo/bar      (if kill_dots is true)
+         * .//./foo//./bar/. becomes ./foo/bar     (if kill_dots is false)
+         * .//./foo//./bar/. becomes foo/bar       (if kill_dots is true)
          */
 
-        for (f = path, t = path; *f; f++) {
+        absolute = path_is_absolute(path);
+
+        f = path;
+        if (kill_dots && *f == '.' && IN_SET(f[1], 0, '/')) {
+                ignore_slash = true;
+                f++;
+        }
+
+        for (t = path; *f; f++) {
 
                 if (*f == '/') {
                         slash = true;
@@ -357,17 +370,21 @@ char *path_kill_slashes(char *path) {
                 }
 
                 if (slash) {
+                        if (kill_dots && *f == '.' && IN_SET(f[1], 0, '/'))
+                                continue;
+
                         slash = false;
-                        *(t++) = '/';
+                        if (ignore_slash)
+                                ignore_slash = false;
+                        else
+                                *(t++) = '/';
                 }
 
                 *(t++) = *f;
         }
 
-        /* Special rule, if we are talking of the root directory, a
-        trailing slash is good */
-
-        if (t == path && slash)
+        /* Special rule, if we are talking of the root directory, a trailing slash is good */
+        if (absolute && t == path)
                 *(t++) = '/';
 
         *t = 0;
@@ -534,7 +551,7 @@ int find_binary(const char *name, char **ret) {
                         /* Found it! */
 
                         if (ret) {
-                                *ret = path_kill_slashes(j);
+                                *ret = path_simplify(j, false);
                                 j = NULL;
                         }
 
@@ -691,12 +708,12 @@ int parse_path_argument_and_warn(const char *path, bool suppress_root, char **ar
         if (r < 0)
                 return log_error_errno(r, "Failed to parse path \"%s\" and make it absolute: %m", path);
 
-        path_kill_slashes(p);
-        if (suppress_root && path_equal(p, "/"))
+        path_simplify(p, false);
+        if (suppress_root && empty_or_root(p))
                 p = mfree(p);
 
-        free(*arg);
-        *arg = p;
+        free_and_replace(*arg, p);
+
         return 0;
 }
 #endif // 0
diff --git a/src/basic/path-util.h b/src/basic/path-util.h
index e1f22ed97..4fabe06e6 100644
--- a/src/basic/path-util.h
+++ b/src/basic/path-util.h
@@ -56,12 +56,12 @@ int path_make_absolute_cwd(const char *p, char **ret);
 #if 0 /// UNNEEDED by elogind
 int path_make_relative(const char *from_dir, const char *to_path, char **_r);
 #endif // 0
-char* path_kill_slashes(char *path);
 char* path_startswith(const char *path, const char *prefix) _pure_;
 int path_compare(const char *a, const char *b) _pure_;
 bool path_equal(const char *a, const char *b) _pure_;
 bool path_equal_or_files_same(const char *a, const char *b, int flags);
 char* path_join(const char *root, const char *path, const char *rest);
+char* path_simplify(char *path, bool kill_dots);
 
 static inline bool path_equal_ptr(const char *a, const char *b) {
         return !!a == !!b && (!a || path_equal(a, b));
@@ -111,11 +111,11 @@ int mkfs_exists(const char *fstype);
  * the tree, to root. Also returns "" (and not "/"!) for the root
  * directory. Excludes the specified directory itself */
 #define PATH_FOREACH_PREFIX(prefix, path) \
-        for (char *_slash = ({ path_kill_slashes(strcpy(prefix, path)); streq(prefix, "/") ? NULL : strrchr(prefix, '/'); }); _slash && ((*_slash = 0), true); _slash = strrchr((prefix), '/'))
+        for (char *_slash = ({ path_simplify(strcpy(prefix, path), false); streq(prefix, "/") ? NULL : strrchr(prefix, '/'); }); _slash && ((*_slash = 0), true); _slash = strrchr((prefix), '/'))
 
 /* Same as PATH_FOREACH_PREFIX but also includes the specified path itself */
 #define PATH_FOREACH_PREFIX_MORE(prefix, path) \
-        for (char *_slash = ({ path_kill_slashes(strcpy(prefix, path)); if (streq(prefix, "/")) prefix[0] = 0; strrchr(prefix, 0); }); _slash && ((*_slash = 0), true); _slash = strrchr((prefix), '/'))
+        for (char *_slash = ({ path_simplify(strcpy(prefix, path), false); if (streq(prefix, "/")) prefix[0] = 0; strrchr(prefix, 0); }); _slash && ((*_slash = 0), true); _slash = strrchr((prefix), '/'))
 
 char *prefix_root(const char *root, const char *path);
 
diff --git a/src/basic/unit-name.c b/src/basic/unit-name.c
index 113d9bb10..12323fb4d 100644
--- a/src/basic/unit-name.c
+++ b/src/basic/unit-name.c
@@ -388,7 +388,7 @@ int unit_name_path_escape(const char *f, char **ret) {
         if (!p)
                 return -ENOMEM;
 
-        path_kill_slashes(p);
+        path_simplify(p, false);
 
         if (empty_or_root(p))
                 s = strdup("-");
diff --git a/src/core/cgroup.c b/src/core/cgroup.c
index a1e66864b..1c8245e0b 100644
--- a/src/core/cgroup.c
+++ b/src/core/cgroup.c
@@ -1520,7 +1520,7 @@ static int unit_attach_pid_to_cgroup_via_bus(Unit *u, pid_t pid, const char *suf
                 return -EINVAL;
 
         pp = strjoina("/", pp, suffix_path);
-        path_kill_slashes(pp);
+        path_simplify(pp, false);
 
         r = sd_bus_call_method(u->manager->system_bus,
                                "org.freedesktop.systemd1",
diff --git a/src/shared/conf-parser.c b/src/shared/conf-parser.c
index eeb93e284..899711e54 100644
--- a/src/shared/conf-parser.c
+++ b/src/shared/conf-parser.c
@@ -41,6 +41,7 @@
 //#include "rlimit-util.h"
 //#include "rlimit-util.h"
 //#include "rlimit-util.h"
+//#include "rlimit-util.h"
 
 int config_item_table_lookup(
                 const void *table,
@@ -757,7 +758,7 @@ int config_parse_path(
         if (!n)
                 return log_oom();
 
-        path_kill_slashes(n);
+        path_simplify(n, false);
 
 finalize:
         free(*s);
diff --git a/src/test/test-path-util.c b/src/test/test-path-util.c
index e7a247027..80bca48e0 100644
--- a/src/test/test-path-util.c
+++ b/src/test/test-path-util.c
@@ -26,6 +26,16 @@
                 assert_se(path_equal(b, a) == !result);   \
         }
 
+static void test_path_simplify(const char *in, const char *out, const char *out_dot) {
+        char *p;
+
+        p = strdupa(in);
+        assert_se(streq(path_simplify(p, false), out));
+
+        p = strdupa(in);
+        assert_se(streq(path_simplify(p, true), out_dot));
+}
+
 static void test_path(void) {
         _cleanup_close_ int fd = -1;
 
@@ -69,15 +79,28 @@ static void test_path(void) {
         assert_se(fd >= 0);
         assert_se(fd_is_mount_point(fd, "/", 0) > 0);
 
-        {
-                char p1[] = "aaa/bbb////ccc";
-                char p2[] = "//aaa/.////ccc";
-                char p3[] = "/./";
-
-                assert_se(path_equal(path_kill_slashes(p1), "aaa/bbb/ccc"));
-                assert_se(path_equal(path_kill_slashes(p2), "/aaa/./ccc"));
-                assert_se(path_equal(path_kill_slashes(p3), "/./"));
-        }
+        test_path_simplify("aaa/bbb////ccc", "aaa/bbb/ccc", "aaa/bbb/ccc");
+        test_path_simplify("//aaa/.////ccc", "/aaa/./ccc", "/aaa/ccc");
+        test_path_simplify("///", "/", "/");
+        test_path_simplify("///.//", "/.", "/");
+        test_path_simplify("///.//.///", "/./.", "/");
+        test_path_simplify("////.././///../.", "/.././../.", "/../..");
+        test_path_simplify(".", ".", "");
+        test_path_simplify("./", ".", "");
+        test_path_simplify(".///.//./.", "./././.", "");
+        test_path_simplify(".///.//././/", "./././.", "");
+        test_path_simplify("//./aaa///.//./.bbb/..///c.//d.dd///..eeee/.",
+                           "/./aaa/././.bbb/../c./d.dd/..eeee/.",
+                           "/aaa/.bbb/../c./d.dd/..eeee");
+        test_path_simplify("//./aaa///.//./.bbb/..///c.//d.dd///..eeee/..",
+                           "/./aaa/././.bbb/../c./d.dd/..eeee/..",
+                           "/aaa/.bbb/../c./d.dd/..eeee/..");
+        test_path_simplify(".//./aaa///.//./.bbb/..///c.//d.dd///..eeee/..",
+                           "././aaa/././.bbb/../c./d.dd/..eeee/..",
+                           "aaa/.bbb/../c./d.dd/..eeee/..");
+        test_path_simplify("..//./aaa///.//./.bbb/..///c.//d.dd///..eeee/..",
+                           ".././aaa/././.bbb/../c./d.dd/..eeee/..",
+                           "../aaa/.bbb/../c./d.dd/..eeee/..");
 
         assert_se(PATH_IN_SET("/bin", "/", "/bin", "/foo"));
         assert_se(PATH_IN_SET("/bin", "/bin"));