+
+/*
+ * Try to remove a hierarchy of empty directories, recursively. Don't unlink
+ * any file. Try to rmdir any empty directory within the hierarchy.
+ */
+LTTNG_HIDDEN
+int utils_recursive_rmdir(const char *path)
+{
+ DIR *dir;
+ size_t path_len;
+ int dir_fd, ret = 0, closeret, is_empty = 1;
+ struct dirent *entry;
+
+ /* Open directory */
+ dir = opendir(path);
+ if (!dir) {
+ PERROR("Cannot open '%s' path", path);
+ return -1;
+ }
+ dir_fd = lttng_dirfd(dir);
+ if (dir_fd < 0) {
+ PERROR("lttng_dirfd");
+ return -1;
+ }
+
+ path_len = strlen(path);
+ while ((entry = readdir(dir))) {
+ struct stat st;
+ size_t name_len;
+ char filename[PATH_MAX];
+
+ if (!strcmp(entry->d_name, ".")
+ || !strcmp(entry->d_name, "..")) {
+ continue;
+ }
+
+ name_len = strlen(entry->d_name);
+ if (path_len + name_len + 2 > sizeof(filename)) {
+ ERR("Failed to remove file: path name too long (%s/%s)",
+ path, entry->d_name);
+ continue;
+ }
+ if (snprintf(filename, sizeof(filename), "%s/%s",
+ path, entry->d_name) < 0) {
+ ERR("Failed to format path.");
+ continue;
+ }
+
+ if (stat(filename, &st)) {
+ PERROR("stat");
+ continue;
+ }
+
+ if (S_ISDIR(st.st_mode)) {
+ char subpath[PATH_MAX];
+
+ strncpy(subpath, path, PATH_MAX);
+ subpath[PATH_MAX - 1] = '\0';
+ strncat(subpath, "/",
+ PATH_MAX - strlen(subpath) - 1);
+ strncat(subpath, entry->d_name,
+ PATH_MAX - strlen(subpath) - 1);
+ if (utils_recursive_rmdir(subpath)) {
+ is_empty = 0;
+ }
+ } else if (S_ISREG(st.st_mode)) {
+ is_empty = 0;
+ } else {
+ ret = -EINVAL;
+ goto end;
+ }
+ }
+end:
+ closeret = closedir(dir);
+ if (closeret) {
+ PERROR("closedir");
+ }
+ if (is_empty) {
+ DBG3("Attempting rmdir %s", path);
+ ret = rmdir(path);
+ }
+ return ret;
+}
+
+LTTNG_HIDDEN
+int utils_truncate_stream_file(int fd, off_t length)
+{
+ int ret;
+ off_t lseek_ret;
+
+ ret = ftruncate(fd, length);
+ if (ret < 0) {
+ PERROR("ftruncate");
+ goto end;
+ }
+ lseek_ret = lseek(fd, length, SEEK_SET);
+ if (lseek_ret < 0) {
+ PERROR("lseek");
+ ret = -1;
+ goto end;
+ }
+end:
+ return ret;
+}
+
+static const char *get_man_bin_path(void)
+{
+ char *env_man_path = lttng_secure_getenv(DEFAULT_MAN_BIN_PATH_ENV);
+
+ if (env_man_path) {
+ return env_man_path;
+ }
+
+ return DEFAULT_MAN_BIN_PATH;
+}
+
+LTTNG_HIDDEN
+int utils_show_help(int section, const char *page_name,
+ const char *help_msg)
+{
+ char section_string[8];
+ const char *man_bin_path = get_man_bin_path();
+ int ret = 0;
+
+ if (help_msg) {
+ printf("%s", help_msg);
+ goto end;
+ }
+
+ /* Section integer -> section string */
+ ret = sprintf(section_string, "%d", section);
+ assert(ret > 0 && ret < 8);
+
+ /*
+ * Execute man pager.
+ *
+ * We provide -M to man here because LTTng-tools can
+ * be installed outside /usr, in which case its man pages are
+ * not located in the default /usr/share/man directory.
+ */
+ ret = execlp(man_bin_path, "man", "-M", MANPATH,
+ section_string, page_name, NULL);
+
+end:
+ return ret;
+}