util: add files_same() helper function

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

diff --git a/src/shared/util.c b/src/shared/util.c
index cffa1abb3061c507e2c239626f238379bd4e4160..10f113bd240975d7f9fc810c21623ad54aba2e67 100644 (file)
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -3198,19 +3198,27 @@ bool on_tty(void) {
         return cached_on_tty;
 }
 
-int running_in_chroot(void) {
-        struct stat a = {}, b = {};
+int files_same(const char *filea, const char *fileb) {
+        struct stat a, b;
 
-        /* Only works as root */
-        if (stat("/proc/1/root", &a) < 0)
+        if (stat(filea, &a) < 0)
                 return -errno;
 
-        if (stat("/", &b) < 0)
+        if (stat(fileb, &b) < 0)
                 return -errno;
 
-        return
-                a.st_dev != b.st_dev ||
-                a.st_ino != b.st_ino;
+        return a.st_dev == b.st_dev &&
+               a.st_ino == b.st_ino;
+}
+
+int running_in_chroot(void) {
+        int ret;
+
+        ret = files_same("/proc/1/root", "/");
+        if (ret < 0)
+                return ret;
+
+        return ret == 0;
 }
 
 static char *ascii_ellipsize_mem(const char *s, size_t old_length, size_t new_length, unsigned percent) {
@@ -3519,25 +3527,21 @@ int signal_from_string_try_harder(const char *s) {
 
 static char *tag_to_udev_node(const char *tagvalue, const char *by) {
         _cleanup_free_ char *t = NULL, *u = NULL;
-        char *dn;
         size_t enc_len;
 
         u = unquote(tagvalue, "\"\'");
-        if (u == NULL)
+        if (!u)
                 return NULL;
 
         enc_len = strlen(u) * 4 + 1;
         t = new(char, enc_len);
-        if (t == NULL)
+        if (!t)
                 return NULL;
 
         if (encode_devnode_name(u, t, enc_len) < 0)
                 return NULL;
 
-        if (asprintf(&dn, "/dev/disk/by-%s/%s", by, t) < 0)
-                return NULL;
-
-        return dn;
+        return strjoin("/dev/disk/by-", by, "/", t, NULL);
 }
 
 char *fstab_node_to_udev_node(const char *p) {
@@ -6339,3 +6343,20 @@ uint64_t physical_memory(void) {
 
         return (uint64_t) mem * (uint64_t) page_size();
 }
+
+char* mount_test_option(const char *haystack, const char *needle) {
+
+        struct mntent me = {
+                .mnt_opts = (char*) haystack
+        };
+
+        assert(needle);
+
+        /* Like glibc's hasmntopt(), but works on a string, not a
+         * struct mntent */
+
+        if (!haystack)
+                return NULL;
+
+        return hasmntopt(&me, needle);
+}