util: introduce random_ull()

[elogind.git] / src / util.c

diff --git a/src/util.c b/src/util.c
index a8ea4a97ab745dbc3ea4400176e10d9bae29f4e9..71409034a4e15cb0c35fbbd2994e520cccfbea7c 100644 (file)
--- a/src/util.c
+++ b/src/util.c
@@ -582,6 +582,26 @@ int readlink_malloc(const char *p, char **r) {
         }
 }
 
         }
 }
 

+int readlink_and_make_absolute(const char *p, char **r) {
+        char *target, *k;
+        int j;
+
+        assert(p);
+        assert(r);
+
+        if ((j = readlink_malloc(p, &target)) < 0)
+                return j;
+
+        k = file_in_same_dir(p, target);
+        free(target);
+
+        if (!k)
+                return -ENOMEM;
+
+        *r = k;
+        return 0;
+}
+

 char *file_name_from_path(const char *p) {
         char *r;
 
 char *file_name_from_path(const char *p) {
         char *r;
 


@@ -2092,6 +2112,55 @@ bool is_device_path(const char *path) {
                 path_startswith(path, "/sys/");
 }
 
                 path_startswith(path, "/sys/");
 }
 

+int dir_is_empty(const char *path) {
+        DIR *d;
+        int r;
+        struct dirent buf, *de;
+
+        if (!(d = opendir(path)))
+                return -errno;
+
+        for (;;) {
+                if ((r = readdir_r(d, &buf, &de)) > 0) {
+                        r = -r;
+                        break;
+                }
+
+                if (!de) {
+                        r = 1;
+                        break;
+                }
+
+                if (!ignore_file(de->d_name)) {
+                        r = 0;
+                        break;
+                }
+        }
+
+        closedir(d);
+        return r;
+}
+
+unsigned long long random_ull(void) {
+        int fd;
+        uint64_t ull;
+        ssize_t r;
+
+        if ((fd = open("/dev/urandom", O_RDONLY|O_CLOEXEC|O_NOCTTY)) < 0)
+                goto fallback;
+
+        r = loop_read(fd, &ull, sizeof(ull));
+        close_nointr_nofail(fd);
+
+        if (r != sizeof(ull))
+                goto fallback;
+
+        return ull;
+
+fallback:
+        return random() * RAND_MAX + random();
+}
+

 static const char *const ioprio_class_table[] = {
         [IOPRIO_CLASS_NONE] = "none",
         [IOPRIO_CLASS_RT] = "realtime",
 static const char *const ioprio_class_table[] = {
         [IOPRIO_CLASS_NONE] = "none",
         [IOPRIO_CLASS_RT] = "realtime",