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 d28caae6c2ebc0fd034acebf2d06fa77bd1c96cb..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) {