util: split-out path-util.[ch]

1 files changed, 371 insertions, 0 deletions

diff --git a/src/shared/path-util.c b/src/shared/path-util.c
new file mode 100644
index 0000000000..ccd7667608
--- /dev/null
+++ b/src/shared/path-util.c
@@ -0,0 +1,371 @@
+/*-*- 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 <assert.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <dirent.h>
+#include <sys/statvfs.h>
+
+#include "macro.h"
+#include "util.h"
+#include "log.h"
+#include "strv.h"
+#include "path-util.h"
+
+bool path_is_absolute(const char *p) {
+        return p[0] == '/';
+}
+
+bool is_path(const char *p) {
+        return !!strchr(p, '/');
+}
+
+char *path_get_file_name(const char *p) {
+        char *r;
+
+        assert(p);
+
+        if ((r = strrchr(p, '/')))
+                return r + 1;
+
+        return (char*) p;
+}
+
+int path_get_parent(const char *path, char **_r) {
+        const char *e, *a = NULL, *b = NULL, *p;
+        char *r;
+        bool slash = false;
+
+        assert(path);
+        assert(_r);
+
+        if (!*path)
+                return -EINVAL;
+
+        for (e = path; *e; e++) {
+
+                if (!slash && *e == '/') {
+                        a = b;
+                        b = e;
+                        slash = true;
+                } else if (slash && *e != '/')
+                        slash = false;
+        }
+
+        if (*(e-1) == '/')
+                p = a;
+        else
+                p = b;
+
+        if (!p)
+                return -EINVAL;
+
+        if (p == path)
+                r = strdup("/");
+        else
+                r = strndup(path, p-path);
+
+        if (!r)
+                return -ENOMEM;
+
+        *_r = r;
+        return 0;
+}
+
+char **path_split_and_make_absolute(const char *p) {
+        char **l;
+        assert(p);
+
+        if (!(l = strv_split(p, ":")))
+                return NULL;
+
+        if (!path_strv_make_absolute_cwd(l)) {
+                strv_free(l);
+                return NULL;
+        }
+
+        return l;
+}
+
+char *path_make_absolute(const char *p, const char *prefix) {
+        assert(p);
+
+        /* Makes every item in the list an absolute path by prepending
+         * the prefix, if specified and necessary */
+
+        if (path_is_absolute(p) || !prefix)
+                return strdup(p);
+
+        return join(prefix, "/", p, NULL);
+}
+
+char *path_make_absolute_cwd(const char *p) {
+        char *cwd, *r;
+
+        assert(p);
+
+        /* Similar to path_make_absolute(), but prefixes with the
+         * current working directory. */
+
+        if (path_is_absolute(p))
+                return strdup(p);
+
+        if (!(cwd = get_current_dir_name()))
+                return NULL;
+
+        r = path_make_absolute(p, cwd);
+        free(cwd);
+
+        return r;
+}
+
+char **path_strv_make_absolute_cwd(char **l) {
+        char **s;
+
+        /* Goes through every item in the string list and makes it
+         * absolute. This works in place and won't rollback any
+         * changes on failure. */
+
+        STRV_FOREACH(s, l) {
+                char *t;
+
+                if (!(t = path_make_absolute_cwd(*s)))
+                        return NULL;
+
+                free(*s);
+                *s = t;
+        }
+
+        return l;
+}
+
+char **path_strv_canonicalize(char **l) {
+        char **s;
+        unsigned k = 0;
+        bool enomem = false;
+
+        if (strv_isempty(l))
+                return l;
+
+        /* Goes through every item in the string list and canonicalize
+         * the path. This works in place and won't rollback any
+         * changes on failure. */
+
+        STRV_FOREACH(s, l) {
+                char *t, *u;
+
+                t = path_make_absolute_cwd(*s);
+                free(*s);
+
+                if (!t) {
+                        enomem = true;
+                        continue;
+                }
+
+                errno = 0;
+                u = canonicalize_file_name(t);
+                free(t);
+
+                if (!u) {
+                        if (errno == ENOMEM || !errno)
+                                enomem = true;
+
+                        continue;
+                }
+
+                l[k++] = u;
+        }
+
+        l[k] = NULL;
+
+        if (enomem)
+                return NULL;
+
+        return l;
+}
+
+char **path_strv_remove_empty(char **l) {
+        char **f, **t;
+
+        if (!l)
+                return NULL;
+
+        for (f = t = l; *f; f++) {
+
+                if (dir_is_empty(*f) > 0) {
+                        free(*f);
+                        continue;
+                }
+
+                *(t++) = *f;
+        }
+
+        *t = NULL;
+        return l;
+}
+
+char *path_kill_slashes(char *path) {
+        char *f, *t;
+        bool slash = false;
+
+        /* Removes redundant inner and trailing slashes. Modifies the
+         * passed string in-place.
+         *
+         * ///foo///bar/ becomes /foo/bar
+         */
+
+        for (f = path, t = path; *f; f++) {
+
+                if (*f == '/') {
+                        slash = true;
+                        continue;
+                }
+
+                if (slash) {
+                        slash = false;
+                        *(t++) = '/';
+                }
+
+                *(t++) = *f;
+        }
+
+        /* Special rule, if we are talking of the root directory, a
+        trailing slash is good */
+
+        if (t == path && slash)
+                *(t++) = '/';
+
+        *t = 0;
+        return path;
+}
+
+bool path_startswith(const char *path, const char *prefix) {
+        assert(path);
+        assert(prefix);
+
+        if ((path[0] == '/') != (prefix[0] == '/'))
+                return false;
+
+        for (;;) {
+                size_t a, b;
+
+                path += strspn(path, "/");
+                prefix += strspn(prefix, "/");
+
+                if (*prefix == 0)
+                        return true;
+
+                if (*path == 0)
+                        return false;
+
+                a = strcspn(path, "/");
+                b = strcspn(prefix, "/");
+
+                if (a != b)
+                        return false;
+
+                if (memcmp(path, prefix, a) != 0)
+                        return false;
+
+                path += a;
+                prefix += b;
+        }
+}
+
+bool path_equal(const char *a, const char *b) {
+        assert(a);
+        assert(b);
+
+        if ((a[0] == '/') != (b[0] == '/'))
+                return false;
+
+        for (;;) {
+                size_t j, k;
+
+                a += strspn(a, "/");
+                b += strspn(b, "/");
+
+                if (*a == 0 && *b == 0)
+                        return true;
+
+                if (*a == 0 || *b == 0)
+                        return false;
+
+                j = strcspn(a, "/");
+                k = strcspn(b, "/");
+
+                if (j != k)
+                        return false;
+
+                if (memcmp(a, b, j) != 0)
+                        return false;
+
+                a += j;
+                b += k;
+        }
+}
+
+int path_is_mount_point(const char *t, bool allow_symlink) {
+        struct stat a, b;
+        char *parent;
+        int r;
+
+        if (allow_symlink)
+                r = stat(t, &a);
+        else
+                r = lstat(t, &a);
+
+        if (r < 0) {
+                if (errno == ENOENT)
+                        return 0;
+
+                return -errno;
+        }
+
+        r = path_get_parent(t, &parent);
+        if (r < 0)
+                return r;
+
+        r = lstat(parent, &b);
+        free(parent);
+
+        if (r < 0)
+                return -errno;
+
+        return a.st_dev != b.st_dev;
+}
+
+int path_is_read_only_fs(const char *path) {
+        struct statvfs st;
+
+        assert(path);
+
+        if (statvfs(path, &st) < 0)
+                return -errno;
+
+        return !!(st.f_flag & ST_RDONLY);
+}