1 /*
2  * Copyright (c) 2018, 2019 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 /* Utilities for dealing with filesystem paths. */
18 
19 #define GOT_DEFAULT_FILE_MODE	(S_IRUSR|S_IWUSR | S_IRGRP | S_IROTH)
20 #define GOT_DEFAULT_DIR_MODE	(S_IRWXU | S_IRGRP|S_IXGRP | S_IROTH|S_IXOTH)
21 
22 /* Determine whether a path is an absolute path. */
23 int got_path_is_absolute(const char *);
24 
25 /*
26  * Return an absolute version of a relative path.
27  * The result is allocated with malloc(3).
28  */
29 char *got_path_get_absolute(const char *);
30 
31 /* 
32  * Normalize a path for internal processing.
33  * The result is allocated with malloc(3).
34  */
35 char *got_path_normalize(const char *);
36 
37 /*
38  * Canonicalize absolute paths by removing redundant path separators
39  * and resolving references to parent directories ("/../").
40  * Relative paths are copied from input to buf as-is.
41  */
42 const struct got_error *got_canonpath(const char *, char *, size_t);
43 
44 /*
45  * Get child part of two absolute paths. The second path must equal the first
46  * path up to some path component, and must be longer than the first path.
47  * The result is allocated with malloc(3).
48  */
49 const struct got_error *got_path_skip_common_ancestor(char **, const char *,
50     const char *);
51 
52 /* Determine whether a path points to the root directory "/" . */
53 int got_path_is_root_dir(const char *);
54 
55 /* Determine whether a path is a path-wise child of another path. */
56 int got_path_is_child(const char *, const char *, size_t);
57 
58 /*
59  * Like strcmp() but orders children in subdirectories directly after
60  * their parents.
61  */
62 int got_path_cmp(const char *, const char *);
63 
64 /*
65  * Path lists allow for predictable concurrent iteration over multiple lists
66  * of paths obtained from disparate sources which don't all provide the same
67  * ordering guarantees (e.g. git trees, file index, and on-disk directories).
68  */
69 struct got_pathlist_entry {
70 	TAILQ_ENTRY(got_pathlist_entry) entry;
71 	const char *path;
72 	void *data; /* data pointer provided to got_pathlist_insert() */
73 };
74 TAILQ_HEAD(got_pathlist_head, got_pathlist_entry);
75 
76 /*
77  * Insert a path into the list of paths in a predictable order.
78  * The caller should already have initialized the list head. This list stores
79  * the pointer to the path as-is, i.e. the path is not copied internally and
80  * must remain available until the list is freed with got_pathlist_free().
81  * If the first argument is not NULL, set it to a pointer to the newly inserted
82  * element, or to a NULL pointer in case the path was already on the list.
83  */
84 const struct got_error *got_pathlist_insert(struct got_pathlist_entry **,
85     struct got_pathlist_head *, const char *, void *);
86 
87 /* Free resources allocated for a path list. */
88 void got_pathlist_free(struct got_pathlist_head *);
89 
90 /* Attempt to create a directory at a given path. */
91 const struct got_error *got_path_mkdir(const char *);
92 
93 /* Determine whether a directory has no files or directories in it. */
94 int got_path_dir_is_empty(const char *);
95 
96 /* dirname(3) with error handling and dynamically allocated result. */
97 const struct got_error *got_path_dirname(char **, const char *);
98 
99 /* Strip trailing slashes from a path; path will be modified in-place. */
100 void got_path_strip_trailing_slashes(char *);
101 
102 /* Look up the absolute path of a program in $PATH */
103 const struct got_error *got_path_find_prog(char **, const char *);
104 
105 /* Create a new file at a specified path, with optional content. */
106 const struct got_error *got_path_create_file(const char *, const char *);