+
+_public_ int sd_journal_stream_fd(const char *tag, int priority, int priority_prefix) {
+ union sockaddr_union sa;
+ int fd;
+ char *header;
+ size_t l;
+ ssize_t r;
+
+ if (priority < 0 || priority > 7)
+ return -EINVAL;
+
+ fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0);
+ if (fd < 0)
+ return -errno;
+
+ zero(sa);
+ sa.un.sun_family = AF_UNIX;
+ strncpy(sa.un.sun_path, "/run/systemd/stdout", sizeof(sa.un.sun_path));
+
+ r = connect(fd, &sa.sa, offsetof(union sockaddr_union, un.sun_path) + strlen(sa.un.sun_path));
+ if (r < 0) {
+ close_nointr_nofail(fd);
+ return -errno;
+ }
+
+ if (!tag)
+ tag = "";
+
+ l = strlen(tag);
+ header = alloca(l + 1 + 2 + 2 + 2);
+
+ memcpy(header, tag, l);
+ header[l++] = '\n';
+ header[l++] = '0' + priority;
+ header[l++] = '\n';
+ header[l++] = '0' + !!priority_prefix;
+ header[l++] = '\n';
+ header[l++] = '0';
+ header[l++] = '\n';
+
+ r = loop_write(fd, header, l, false);
+ if (r < 0) {
+ close_nointr_nofail(fd);
+ return (int) r;
+ }
+
+ if ((size_t) r != l) {
+ close_nointr_nofail(fd);
+ return -errno;
+ }
+
+ return fd;
+}