path-util: unify code for detecting OS trees

[elogind.git] / src / shared / path-util.c

diff --git a/src/shared/path-util.c b/src/shared/path-util.c
index 2dddc8f2f689001e4b5dbd8dab206a9c01d5b508..b623fc3dd5adeb9cad7034ee05425b73dd29ab7b 100644 (file)
--- a/src/shared/path-util.c
+++ b/src/shared/path-util.c
@@ -135,7 +135,8 @@ char *path_make_absolute_cwd(const char *p) {
         if (path_is_absolute(p))
                 return strdup(p);
 
-        if (!(cwd = get_current_dir_name()))
+        cwd = get_current_dir_name();
+        if (!cwd)
                 return NULL;
 
         r = path_make_absolute(p, cwd);
@@ -181,6 +182,7 @@ char **path_strv_canonicalize(char **l) {
 
                 t = path_make_absolute_cwd(*s);
                 free(*s);
+                *s = NULL;
 
                 if (!t) {
                         enomem = true;
@@ -189,14 +191,18 @@ char **path_strv_canonicalize(char **l) {
 
                 errno = 0;
                 u = canonicalize_file_name(t);
-                free(t);
-
                 if (!u) {
-                        if (errno == ENOMEM || !errno)
-                                enomem = true;
-
-                        continue;
-                }
+                        if (errno == ENOENT)
+                                u = t;
+                        else {
+                                free(t);
+                                if (errno == ENOMEM || !errno)
+                                        enomem = true;
+
+                                continue;
+                        }
+                } else
+                        free(t);
 
                 l[k++] = u;
         }
@@ -209,24 +215,14 @@ char **path_strv_canonicalize(char **l) {
         return l;
 }
 
-char **path_strv_remove_empty(char **l) {
-        char **f, **t;
+char **path_strv_canonicalize_uniq(char **l) {
+        if (strv_isempty(l))
+                return l;
 
-        if (!l)
+        if (!path_strv_canonicalize(l))
                 return NULL;
 
-        for (f = t = l; *f; f++) {
-
-                if (dir_is_empty(*f) > 0) {
-                        free(*f);
-                        continue;
-                }
-
-                *(t++) = *f;
-        }
-
-        *t = NULL;
-        return l;
+        return strv_uniq(l);
 }
 
 char *path_kill_slashes(char *path) {
@@ -264,12 +260,12 @@ char *path_kill_slashes(char *path) {
         return path;
 }
 
-bool path_startswith(const char *path, const char *prefix) {
+char* path_startswith(const char *path, const char *prefix) {
         assert(path);
         assert(prefix);
 
         if ((path[0] == '/') != (prefix[0] == '/'))
-                return false;
+                return NULL;
 
         for (;;) {
                 size_t a, b;
@@ -278,19 +274,19 @@ bool path_startswith(const char *path, const char *prefix) {
                 prefix += strspn(prefix, "/");
 
                 if (*prefix == 0)
-                        return true;
+                        return (char*) path;
 
                 if (*path == 0)
-                        return false;
+                        return NULL;
 
                 a = strcspn(path, "/");
                 b = strcspn(prefix, "/");
 
                 if (a != b)
-                        return false;
+                        return NULL;
 
                 if (memcmp(path, prefix, a) != 0)
-                        return false;
+                        return NULL;
 
                 path += a;
                 prefix += b;
@@ -349,8 +345,8 @@ int path_is_mount_point(const char *t, bool allow_symlink) {
 
         r = name_to_handle_at(AT_FDCWD, t, h, &mount_id, allow_symlink ? AT_SYMLINK_FOLLOW : 0);
         if (r < 0) {
-                if (errno == ENOTSUP)
-                        /* This file system does not support
+                if (errno == ENOSYS || errno == ENOTSUP)
+                        /* This kernel or file system does not support
                          * name_to_handle_at(), hence fallback to the
                          * traditional stat() logic */
                         goto fallback;
@@ -385,10 +381,14 @@ fallback:
         if (allow_symlink)
                 r = stat(t, &a);
         else
-                r = lstat(t, &b);
+                r = lstat(t, &a);
+
+        if (r < 0) {
+                if (errno == ENOENT)
+                        return 0;
 
-        if (r < 0)
                 return -errno;
+        }
 
         r = path_get_parent(t, &parent);
         if (r < 0)
@@ -413,3 +413,15 @@ int path_is_read_only_fs(const char *path) {
 
         return !!(st.f_flag & ST_RDONLY);
 }
+
+int path_is_os_tree(const char *path) {
+        char *p;
+        int r;
+
+        /* We use /etc/os-release as flag file if something is an OS */
+
+        p = strappenda(path, "/etc/os-release");
+        r = access(p, F_OK);
+
+        return r < 0 ? 0 : 1;
+}