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-rw-r--r--src/basic/stat-util.c216
1 files changed, 216 insertions, 0 deletions
diff --git a/src/basic/stat-util.c b/src/basic/stat-util.c
new file mode 100644
index 0000000000..3bc66b3be7
--- /dev/null
+++ b/src/basic/stat-util.c
@@ -0,0 +1,216 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+ This file is part of systemd.
+
+ Copyright 2010-2012 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 <fcntl.h>
+#include <linux/magic.h>
+#include <sys/statvfs.h>
+#include <unistd.h>
+
+#include "dirent-util.h"
+#include "fd-util.h"
+#include "macro.h"
+#include "missing.h"
+#include "stat-util.h"
+#include "string-util.h"
+
+int is_symlink(const char *path) {
+ struct stat info;
+
+ assert(path);
+
+ if (lstat(path, &info) < 0)
+ return -errno;
+
+ return !!S_ISLNK(info.st_mode);
+}
+
+int is_dir(const char* path, bool follow) {
+ struct stat st;
+ int r;
+
+ assert(path);
+
+ if (follow)
+ r = stat(path, &st);
+ else
+ r = lstat(path, &st);
+ if (r < 0)
+ return -errno;
+
+ return !!S_ISDIR(st.st_mode);
+}
+
+int is_device_node(const char *path) {
+ struct stat info;
+
+ assert(path);
+
+ if (lstat(path, &info) < 0)
+ return -errno;
+
+ return !!(S_ISBLK(info.st_mode) || S_ISCHR(info.st_mode));
+}
+
+int dir_is_empty(const char *path) {
+ _cleanup_closedir_ DIR *d;
+ struct dirent *de;
+
+ d = opendir(path);
+ if (!d)
+ return -errno;
+
+ FOREACH_DIRENT(de, d, return -errno)
+ return 0;
+
+ return 1;
+}
+
+bool null_or_empty(struct stat *st) {
+ assert(st);
+
+ if (S_ISREG(st->st_mode) && st->st_size <= 0)
+ return true;
+
+ /* We don't want to hardcode the major/minor of /dev/null,
+ * hence we do a simpler "is this a device node?" check. */
+
+ if (S_ISCHR(st->st_mode) || S_ISBLK(st->st_mode))
+ return true;
+
+ return false;
+}
+
+int null_or_empty_path(const char *fn) {
+ struct stat st;
+
+ assert(fn);
+
+ if (stat(fn, &st) < 0)
+ return -errno;
+
+ return null_or_empty(&st);
+}
+
+int null_or_empty_fd(int fd) {
+ struct stat st;
+
+ assert(fd >= 0);
+
+ if (fstat(fd, &st) < 0)
+ return -errno;
+
+ return null_or_empty(&st);
+}
+
+int path_is_read_only_fs(const char *path) {
+ struct statvfs st;
+
+ assert(path);
+
+ if (statvfs(path, &st) < 0)
+ return -errno;
+
+ if (st.f_flag & ST_RDONLY)
+ return true;
+
+ /* On NFS, statvfs() might not reflect whether we can actually
+ * write to the remote share. Let's try again with
+ * access(W_OK) which is more reliable, at least sometimes. */
+ if (access(path, W_OK) < 0 && errno == EROFS)
+ return true;
+
+ return false;
+}
+
+int path_is_os_tree(const char *path) {
+ char *p;
+ int r;
+
+ assert(path);
+
+ /* We use /usr/lib/os-release as flag file if something is an OS */
+ p = strjoina(path, "/usr/lib/os-release");
+ r = access(p, F_OK);
+ if (r >= 0)
+ return 1;
+
+ /* Also check for the old location in /etc, just in case. */
+ p = strjoina(path, "/etc/os-release");
+ r = access(p, F_OK);
+
+ return r >= 0;
+}
+
+int files_same(const char *filea, const char *fileb) {
+ struct stat a, b;
+
+ assert(filea);
+ assert(fileb);
+
+ if (stat(filea, &a) < 0)
+ return -errno;
+
+ if (stat(fileb, &b) < 0)
+ return -errno;
+
+ return a.st_dev == b.st_dev &&
+ a.st_ino == b.st_ino;
+}
+
+bool is_fs_type(const struct statfs *s, statfs_f_type_t magic_value) {
+ assert(s);
+ assert_cc(sizeof(statfs_f_type_t) >= sizeof(s->f_type));
+
+ return F_TYPE_EQUAL(s->f_type, magic_value);
+}
+
+int fd_check_fstype(int fd, statfs_f_type_t magic_value) {
+ struct statfs s;
+
+ if (fstatfs(fd, &s) < 0)
+ return -errno;
+
+ return is_fs_type(&s, magic_value);
+}
+
+int path_check_fstype(const char *path, statfs_f_type_t magic_value) {
+ _cleanup_close_ int fd = -1;
+
+ fd = open(path, O_RDONLY);
+ if (fd < 0)
+ return -errno;
+
+ return fd_check_fstype(fd, magic_value);
+}
+
+bool is_temporary_fs(const struct statfs *s) {
+ return is_fs_type(s, TMPFS_MAGIC) ||
+ is_fs_type(s, RAMFS_MAGIC);
+}
+
+int fd_is_temporary_fs(int fd) {
+ struct statfs s;
+
+ if (fstatfs(fd, &s) < 0)
+ return -errno;
+
+ return is_temporary_fs(&s);
+}