/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. Copyright 2012 Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include <errno.h> #include <unistd.h> #include "log.h" #include "util.h" #include "unit-name.h" #include "path-util.h" /* * Implements the logic described in * http://freedesktop.org/wiki/Software/systemd/SystemUpdates */ static const char *arg_dest = "/tmp"; static int generate_symlink(void) { struct stat st; char *p; if (lstat("/system-update", &st) < 0) { if (errno == ENOENT) return 0; log_error("Failed to check for system update: %m"); return -EINVAL; } p = strappend(arg_dest, "/default.target"); if (!p) return log_oom(); if (symlink(SYSTEM_DATA_UNIT_PATH "/system-update.target", p) < 0) { free(p); log_error("Failed to create symlink: %m"); return -errno; } free(p); return 0; } int main(int argc, char *argv[]) { int r; if (argc > 1 && argc != 4) { log_error("This program takes three or no arguments."); return EXIT_FAILURE; } if (argc > 1) arg_dest = argv[2]; log_set_target(LOG_TARGET_SAFE); log_parse_environment(); log_open(); umask(0022); r = generate_symlink(); return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS; }