+static inline bool tag_needs_update(bool given, const char *tag,
+ const char *arg)
+{
+ return given && (!tag || strcmp(tag, arg) != 0);
+}
+
+static int rewrite_tags(const char *name, int input_fd, void *map,
+ size_t map_size, int audio_format_id, struct afh_info *afhi)
+{
+ struct taginfo *tags = &afhi->tags;
+ bool modified = false;
+ char *tmp_name;
+ int output_fd = -1, ret;
+ struct stat sb;
+
+ if (tag_needs_update(conf.year_given, tags->year, conf.year_arg)) {
+ free(tags->year);
+ tags->year = para_strdup(conf.year_arg);
+ modified = true;
+ }
+ if (tag_needs_update(conf.title_given, tags->title, conf.title_arg)) {
+ free(tags->title);
+ tags->title = para_strdup(conf.title_arg);
+ modified = true;
+ }
+ if (tag_needs_update(conf.artist_given, tags->artist,
+ conf.artist_arg)) {
+ free(tags->artist);
+ tags->artist = para_strdup(conf.artist_arg);
+ modified = true;
+ }
+ if (tag_needs_update(conf.album_given, tags->album, conf.album_arg)) {
+ free(tags->album);
+ tags->album = para_strdup(conf.album_arg);
+ modified = true;
+ }
+ if (tag_needs_update(conf.comment_given, tags->comment,
+ conf.comment_arg)) {
+ free(tags->comment);
+ tags->comment = para_strdup(conf.comment_arg);
+ modified = true;
+ }
+ if (!modified) {
+ PARA_WARNING_LOG("no modifications necessary\n");
+ return 0;
+ }
+ /*
+ * mkstmp() creates the temporary file with permissions 0600, but we
+ * like it to have the same permissions as the original file, so we
+ * have to get this information.
+ */
+ if (fstat(input_fd, &sb) < 0) {
+ ret = -ERRNO_TO_PARA_ERROR(errno);
+ PARA_ERROR_LOG("failed to fstat fd %d (%s)\n", input_fd, name);
+ return ret;
+ }
+ tmp_name = make_message("%s.XXXXXX", name);
+ ret = mkstemp(tmp_name);
+ if (ret < 0) {
+ ret = -ERRNO_TO_PARA_ERROR(errno);
+ PARA_ERROR_LOG("could not create temporary file\n");
+ goto out;
+ }
+ output_fd = ret;
+ if (fchmod(output_fd, sb.st_mode) < 0) {
+ ret = -ERRNO_TO_PARA_ERROR(errno);
+ PARA_ERROR_LOG("failed to fchmod fd %d (%s)\n", output_fd,
+ tmp_name);
+ goto out;
+ }
+ ret = afh_rewrite_tags(audio_format_id, map, map_size, tags, output_fd,
+ tmp_name);
+ if (ret < 0)
+ goto out;
+ if (conf.backup_given) {
+ char *backup_name = make_message("%s~", name);
+ ret = xrename(name, backup_name);
+ free(backup_name);
+ if (ret < 0)
+ goto out;
+ }
+ ret = xrename(tmp_name, name);
+out:
+ if (ret < 0 && output_fd >= 0)
+ unlink(tmp_name); /* ignore errors */
+ free(tmp_name);
+ if (output_fd >= 0)
+ close(output_fd);
+ return ret;
+}
+