From f7a649ae84b76e91ab70db924190727f9a2b7c22 Mon Sep 17 00:00:00 2001
From: Luke Shumaker <lukeshu@sbcglobal.net>
Date: Sun, 12 Jun 2016 17:44:16 -0400
Subject: ./move.sh

---
 src/libbasic/path-util.c | 816 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 816 insertions(+)
 create mode 100644 src/libbasic/path-util.c

(limited to 'src/libbasic/path-util.c')

diff --git a/src/libbasic/path-util.c b/src/libbasic/path-util.c
new file mode 100644
index 0000000000..b2fa81a294
--- /dev/null
+++ b/src/libbasic/path-util.c
@@ -0,0 +1,816 @@
+/***
+  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 <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+/* When we include libgen.h because we need dirname() we immediately
+ * undefine basename() since libgen.h defines it as a macro to the
+ * POSIX version which is really broken. We prefer GNU basename(). */
+#include <libgen.h>
+#undef basename
+
+#include "alloc-util.h"
+#include "extract-word.h"
+#include "fs-util.h"
+#include "log.h"
+#include "macro.h"
+#include "missing.h"
+#include "path-util.h"
+#include "stat-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "time-util.h"
+
+bool path_is_absolute(const char *p) {
+        return p[0] == '/';
+}
+
+bool is_path(const char *p) {
+        return !!strchr(p, '/');
+}
+
+int path_split_and_make_absolute(const char *p, char ***ret) {
+        char **l;
+        int r;
+
+        assert(p);
+        assert(ret);
+
+        l = strv_split(p, ":");
+        if (!l)
+                return -ENOMEM;
+
+        r = path_strv_make_absolute_cwd(l);
+        if (r < 0) {
+                strv_free(l);
+                return r;
+        }
+
+        *ret = l;
+        return r;
+}
+
+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 strjoin(prefix, "/", p, NULL);
+}
+
+int path_make_absolute_cwd(const char *p, char **ret) {
+        char *c;
+
+        assert(p);
+        assert(ret);
+
+        /* Similar to path_make_absolute(), but prefixes with the
+         * current working directory. */
+
+        if (path_is_absolute(p))
+                c = strdup(p);
+        else {
+                _cleanup_free_ char *cwd = NULL;
+
+                cwd = get_current_dir_name();
+                if (!cwd)
+                        return negative_errno();
+
+                c = strjoin(cwd, "/", p, NULL);
+        }
+        if (!c)
+                return -ENOMEM;
+
+        *ret = c;
+        return 0;
+}
+
+int path_make_relative(const char *from_dir, const char *to_path, char **_r) {
+        char *r, *p;
+        unsigned n_parents;
+
+        assert(from_dir);
+        assert(to_path);
+        assert(_r);
+
+        /* Strips the common part, and adds ".." elements as necessary. */
+
+        if (!path_is_absolute(from_dir))
+                return -EINVAL;
+
+        if (!path_is_absolute(to_path))
+                return -EINVAL;
+
+        /* Skip the common part. */
+        for (;;) {
+                size_t a;
+                size_t b;
+
+                from_dir += strspn(from_dir, "/");
+                to_path += strspn(to_path, "/");
+
+                if (!*from_dir) {
+                        if (!*to_path)
+                                /* from_dir equals to_path. */
+                                r = strdup(".");
+                        else
+                                /* from_dir is a parent directory of to_path. */
+                                r = strdup(to_path);
+
+                        if (!r)
+                                return -ENOMEM;
+
+                        path_kill_slashes(r);
+
+                        *_r = r;
+                        return 0;
+                }
+
+                if (!*to_path)
+                        break;
+
+                a = strcspn(from_dir, "/");
+                b = strcspn(to_path, "/");
+
+                if (a != b)
+                        break;
+
+                if (memcmp(from_dir, to_path, a) != 0)
+                        break;
+
+                from_dir += a;
+                to_path += b;
+        }
+
+        /* If we're here, then "from_dir" has one or more elements that need to
+         * be replaced with "..". */
+
+        /* Count the number of necessary ".." elements. */
+        for (n_parents = 0;;) {
+                from_dir += strspn(from_dir, "/");
+
+                if (!*from_dir)
+                        break;
+
+                from_dir += strcspn(from_dir, "/");
+                n_parents++;
+        }
+
+        r = malloc(n_parents * 3 + strlen(to_path) + 1);
+        if (!r)
+                return -ENOMEM;
+
+        for (p = r; n_parents > 0; n_parents--, p += 3)
+                memcpy(p, "../", 3);
+
+        strcpy(p, to_path);
+        path_kill_slashes(r);
+
+        *_r = r;
+        return 0;
+}
+
+int path_strv_make_absolute_cwd(char **l) {
+        char **s;
+        int r;
+
+        /* 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;
+
+                r = path_make_absolute_cwd(*s, &t);
+                if (r < 0)
+                        return r;
+
+                free(*s);
+                *s = t;
+        }
+
+        return 0;
+}
+
+char **path_strv_resolve(char **l, const char *prefix) {
+        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;
+                _cleanup_free_ char *orig = NULL;
+
+                if (!path_is_absolute(*s)) {
+                        free(*s);
+                        continue;
+                }
+
+                if (prefix) {
+                        orig = *s;
+                        t = strappend(prefix, orig);
+                        if (!t) {
+                                enomem = true;
+                                continue;
+                        }
+                } else
+                        t = *s;
+
+                errno = 0;
+                u = canonicalize_file_name(t);
+                if (!u) {
+                        if (errno == ENOENT) {
+                                if (prefix) {
+                                        u = orig;
+                                        orig = NULL;
+                                        free(t);
+                                } else
+                                        u = t;
+                        } else {
+                                free(t);
+                                if (errno == ENOMEM || errno == 0)
+                                        enomem = true;
+
+                                continue;
+                        }
+                } else if (prefix) {
+                        char *x;
+
+                        free(t);
+                        x = path_startswith(u, prefix);
+                        if (x) {
+                                /* restore the slash if it was lost */
+                                if (!startswith(x, "/"))
+                                        *(--x) = '/';
+
+                                t = strdup(x);
+                                free(u);
+                                if (!t) {
+                                        enomem = true;
+                                        continue;
+                                }
+                                u = t;
+                        } else {
+                                /* canonicalized path goes outside of
+                                 * prefix, keep the original path instead */
+                                free(u);
+                                u = orig;
+                                orig = NULL;
+                        }
+                } else
+                        free(t);
+
+                l[k++] = u;
+        }
+
+        l[k] = NULL;
+
+        if (enomem)
+                return NULL;
+
+        return l;
+}
+
+char **path_strv_resolve_uniq(char **l, const char *prefix) {
+
+        if (strv_isempty(l))
+                return l;
+
+        if (!path_strv_resolve(l, prefix))
+                return NULL;
+
+        return strv_uniq(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;
+}
+
+char* path_startswith(const char *path, const char *prefix) {
+        assert(path);
+        assert(prefix);
+
+        if ((path[0] == '/') != (prefix[0] == '/'))
+                return NULL;
+
+        for (;;) {
+                size_t a, b;
+
+                path += strspn(path, "/");
+                prefix += strspn(prefix, "/");
+
+                if (*prefix == 0)
+                        return (char*) path;
+
+                if (*path == 0)
+                        return NULL;
+
+                a = strcspn(path, "/");
+                b = strcspn(prefix, "/");
+
+                if (a != b)
+                        return NULL;
+
+                if (memcmp(path, prefix, a) != 0)
+                        return NULL;
+
+                path += a;
+                prefix += b;
+        }
+}
+
+int path_compare(const char *a, const char *b) {
+        int d;
+
+        assert(a);
+        assert(b);
+
+        /* A relative path and an abolute path must not compare as equal.
+         * Which one is sorted before the other does not really matter.
+         * Here a relative path is ordered before an absolute path. */
+        d = (a[0] == '/') - (b[0] == '/');
+        if (d != 0)
+                return d;
+
+        for (;;) {
+                size_t j, k;
+
+                a += strspn(a, "/");
+                b += strspn(b, "/");
+
+                if (*a == 0 && *b == 0)
+                        return 0;
+
+                /* Order prefixes first: "/foo" before "/foo/bar" */
+                if (*a == 0)
+                        return -1;
+                if (*b == 0)
+                        return 1;
+
+                j = strcspn(a, "/");
+                k = strcspn(b, "/");
+
+                /* Alphabetical sort: "/foo/aaa" before "/foo/b" */
+                d = memcmp(a, b, MIN(j, k));
+                if (d != 0)
+                        return (d > 0) - (d < 0); /* sign of d */
+
+                /* Sort "/foo/a" before "/foo/aaa" */
+                d = (j > k) - (j < k);  /* sign of (j - k) */
+                if (d != 0)
+                        return d;
+
+                a += j;
+                b += k;
+        }
+}
+
+bool path_equal(const char *a, const char *b) {
+        return path_compare(a, b) == 0;
+}
+
+bool path_equal_or_files_same(const char *a, const char *b) {
+        return path_equal(a, b) || files_same(a, b) > 0;
+}
+
+char* path_join(const char *root, const char *path, const char *rest) {
+        assert(path);
+
+        if (!isempty(root))
+                return strjoin(root, endswith(root, "/") ? "" : "/",
+                               path[0] == '/' ? path+1 : path,
+                               rest ? (endswith(path, "/") ? "" : "/") : NULL,
+                               rest && rest[0] == '/' ? rest+1 : rest,
+                               NULL);
+        else
+                return strjoin(path,
+                               rest ? (endswith(path, "/") ? "" : "/") : NULL,
+                               rest && rest[0] == '/' ? rest+1 : rest,
+                               NULL);
+}
+
+int find_binary(const char *name, char **ret) {
+        int last_error, r;
+        const char *p;
+
+        assert(name);
+
+        if (is_path(name)) {
+                if (access(name, X_OK) < 0)
+                        return -errno;
+
+                if (ret) {
+                        r = path_make_absolute_cwd(name, ret);
+                        if (r < 0)
+                                return r;
+                }
+
+                return 0;
+        }
+
+        /**
+         * Plain getenv, not secure_getenv, because we want
+         * to actually allow the user to pick the binary.
+         */
+        p = getenv("PATH");
+        if (!p)
+                p = DEFAULT_PATH;
+
+        last_error = -ENOENT;
+
+        for (;;) {
+                _cleanup_free_ char *j = NULL, *element = NULL;
+
+                r = extract_first_word(&p, &element, ":", EXTRACT_RELAX|EXTRACT_DONT_COALESCE_SEPARATORS);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        break;
+
+                if (!path_is_absolute(element))
+                        continue;
+
+                j = strjoin(element, "/", name, NULL);
+                if (!j)
+                        return -ENOMEM;
+
+                if (access(j, X_OK) >= 0) {
+                        /* Found it! */
+
+                        if (ret) {
+                                *ret = path_kill_slashes(j);
+                                j = NULL;
+                        }
+
+                        return 0;
+                }
+
+                last_error = -errno;
+        }
+
+        return last_error;
+}
+
+bool paths_check_timestamp(const char* const* paths, usec_t *timestamp, bool update) {
+        bool changed = false;
+        const char* const* i;
+
+        assert(timestamp);
+
+        if (paths == NULL)
+                return false;
+
+        STRV_FOREACH(i, paths) {
+                struct stat stats;
+                usec_t u;
+
+                if (stat(*i, &stats) < 0)
+                        continue;
+
+                u = timespec_load(&stats.st_mtim);
+
+                /* first check */
+                if (*timestamp >= u)
+                        continue;
+
+                log_debug("timestamp of '%s' changed", *i);
+
+                /* update timestamp */
+                if (update) {
+                        *timestamp = u;
+                        changed = true;
+                } else
+                        return true;
+        }
+
+        return changed;
+}
+
+static int binary_is_good(const char *binary) {
+        _cleanup_free_ char *p = NULL, *d = NULL;
+        int r;
+
+        r = find_binary(binary, &p);
+        if (r == -ENOENT)
+                return 0;
+        if (r < 0)
+                return r;
+
+        /* An fsck that is linked to /bin/true is a non-existent
+         * fsck */
+
+        r = readlink_malloc(p, &d);
+        if (r == -EINVAL) /* not a symlink */
+                return 1;
+        if (r < 0)
+                return r;
+
+        return !PATH_IN_SET(d, "true"
+                               "/bin/true",
+                               "/usr/bin/true",
+                               "/dev/null");
+}
+
+int fsck_exists(const char *fstype) {
+        const char *checker;
+
+        assert(fstype);
+
+        if (streq(fstype, "auto"))
+                return -EINVAL;
+
+        checker = strjoina("fsck.", fstype);
+        return binary_is_good(checker);
+}
+
+int mkfs_exists(const char *fstype) {
+        const char *mkfs;
+
+        assert(fstype);
+
+        if (streq(fstype, "auto"))
+                return -EINVAL;
+
+        mkfs = strjoina("mkfs.", fstype);
+        return binary_is_good(mkfs);
+}
+
+char *prefix_root(const char *root, const char *path) {
+        char *n, *p;
+        size_t l;
+
+        /* If root is passed, prefixes path with it. Otherwise returns
+         * it as is. */
+
+        assert(path);
+
+        /* First, drop duplicate prefixing slashes from the path */
+        while (path[0] == '/' && path[1] == '/')
+                path++;
+
+        if (isempty(root) || path_equal(root, "/"))
+                return strdup(path);
+
+        l = strlen(root) + 1 + strlen(path) + 1;
+
+        n = new(char, l);
+        if (!n)
+                return NULL;
+
+        p = stpcpy(n, root);
+
+        while (p > n && p[-1] == '/')
+                p--;
+
+        if (path[0] != '/')
+                *(p++) = '/';
+
+        strcpy(p, path);
+        return n;
+}
+
+int parse_path_argument_and_warn(const char *path, bool suppress_root, char **arg) {
+        char *p;
+        int r;
+
+        /*
+         * This function is intended to be used in command line
+         * parsers, to handle paths that are passed in. It makes the
+         * path absolute, and reduces it to NULL if omitted or
+         * root (the latter optionally).
+         *
+         * NOTE THAT THIS WILL FREE THE PREVIOUS ARGUMENT POINTER ON
+         * SUCCESS! Hence, do not pass in uninitialized pointers.
+         */
+
+        if (isempty(path)) {
+                *arg = mfree(*arg);
+                return 0;
+        }
+
+        r = path_make_absolute_cwd(path, &p);
+        if (r < 0)
+                return log_error_errno(r, "Failed to parse path \"%s\" and make it absolute: %m", path);
+
+        path_kill_slashes(p);
+        if (suppress_root && path_equal(p, "/"))
+                p = mfree(p);
+
+        free(*arg);
+        *arg = p;
+        return 0;
+}
+
+char* dirname_malloc(const char *path) {
+        char *d, *dir, *dir2;
+
+        assert(path);
+
+        d = strdup(path);
+        if (!d)
+                return NULL;
+
+        dir = dirname(d);
+        assert(dir);
+
+        if (dir == d)
+                return d;
+
+        dir2 = strdup(dir);
+        free(d);
+
+        return dir2;
+}
+
+bool filename_is_valid(const char *p) {
+        const char *e;
+
+        if (isempty(p))
+                return false;
+
+        if (streq(p, "."))
+                return false;
+
+        if (streq(p, ".."))
+                return false;
+
+        e = strchrnul(p, '/');
+        if (*e != 0)
+                return false;
+
+        if (e - p > FILENAME_MAX)
+                return false;
+
+        return true;
+}
+
+bool path_is_safe(const char *p) {
+
+        if (isempty(p))
+                return false;
+
+        if (streq(p, "..") || startswith(p, "../") || endswith(p, "/..") || strstr(p, "/../"))
+                return false;
+
+        if (strlen(p)+1 > PATH_MAX)
+                return false;
+
+        /* The following two checks are not really dangerous, but hey, they still are confusing */
+        if (streq(p, ".") || startswith(p, "./") || endswith(p, "/.") || strstr(p, "/./"))
+                return false;
+
+        if (strstr(p, "//"))
+                return false;
+
+        return true;
+}
+
+char *file_in_same_dir(const char *path, const char *filename) {
+        char *e, *ret;
+        size_t k;
+
+        assert(path);
+        assert(filename);
+
+        /* This removes the last component of path and appends
+         * filename, unless the latter is absolute anyway or the
+         * former isn't */
+
+        if (path_is_absolute(filename))
+                return strdup(filename);
+
+        e = strrchr(path, '/');
+        if (!e)
+                return strdup(filename);
+
+        k = strlen(filename);
+        ret = new(char, (e + 1 - path) + k + 1);
+        if (!ret)
+                return NULL;
+
+        memcpy(mempcpy(ret, path, e + 1 - path), filename, k + 1);
+        return ret;
+}
+
+bool hidden_or_backup_file(const char *filename) {
+        const char *p;
+
+        assert(filename);
+
+        if (filename[0] == '.' ||
+            streq(filename, "lost+found") ||
+            streq(filename, "aquota.user") ||
+            streq(filename, "aquota.group") ||
+            endswith(filename, "~"))
+                return true;
+
+        p = strrchr(filename, '.');
+        if (!p)
+                return false;
+
+        /* Please, let's not add more entries to the list below. If external projects think it's a good idea to come up
+         * with always new suffixes and that everybody else should just adjust to that, then it really should be on
+         * them. Hence, in future, let's not add any more entries. Instead, let's ask those packages to instead adopt
+         * one of the generic suffixes/prefixes for hidden files or backups, possibly augmented with an additional
+         * string. Specifically: there's now:
+         *
+         *    The generic suffixes "~" and ".bak" for backup files
+         *    The generic prefix "." for hidden files
+         *
+         * Thus, if a new package manager "foopkg" wants its own set of ".foopkg-new", ".foopkg-old", ".foopkg-dist"
+         * or so registered, let's refuse that and ask them to use ".foopkg.new", ".foopkg.old" or ".foopkg~" instead.
+         */
+
+        return STR_IN_SET(p + 1,
+                          "rpmnew",
+                          "rpmsave",
+                          "rpmorig",
+                          "dpkg-old",
+                          "dpkg-new",
+                          "dpkg-tmp",
+                          "dpkg-dist",
+                          "dpkg-bak",
+                          "dpkg-backup",
+                          "dpkg-remove",
+                          "ucf-new",
+                          "ucf-old",
+                          "ucf-dist",
+                          "swp",
+                          "bak",
+                          "old",
+                          "new");
+}
+
+bool is_device_path(const char *path) {
+
+        /* Returns true on paths that refer to a device, either in
+         * sysfs or in /dev */
+
+        return
+                path_startswith(path, "/dev/") ||
+                path_startswith(path, "/sys/");
+}
-- 
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