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  * Canonicalize absolute paths by removing redundant path separators
33  * and resolving references to parent directories ("/../").
34  * Relative paths are copied from input to buf as-is.
35  */
36 const struct got_error *got_canonpath(const char *, char *, size_t);
37 
38 /*
39  * Get child part of two absolute paths. The second path must equal the first
40  * path up to some path component, and must be longer than the first path.
41  * The result is allocated with malloc(3).
42  */
43 const struct got_error *got_path_skip_common_ancestor(char **, const char *,
44     const char *);
45 
46 /* Determine whether a path points to the root directory "/" . */
47 int got_path_is_root_dir(const char *);
48 
49 /* Determine whether a path is a path-wise child of another path. */
50 int got_path_is_child(const char *, const char *, size_t);
51 
52 /*
53  * Like strcmp() but orders children in subdirectories directly after
54  * their parents. String lengths must also be passed in.
55  */
56 int got_path_cmp(const char *, const char *, size_t, size_t);
57 
58 /*
59  * Path lists allow for predictable concurrent iteration over multiple lists
60  * of paths obtained from disparate sources which don't all provide the same
61  * ordering guarantees (e.g. git trees, file index, and on-disk directories).
62  */
63 struct got_pathlist_entry {
64 	TAILQ_ENTRY(got_pathlist_entry) entry;
65 	const char *path;
66 	size_t path_len;
67 	void *data; /* data pointer provided to got_pathlist_insert() */
68 };
69 TAILQ_HEAD(got_pathlist_head, got_pathlist_entry);
70 
71 /*
72  * Insert a path into the list of paths in a predictable order.
73  * The caller should already have initialized the list head. This list stores
74  * the pointer to the path as-is, i.e. the path is not copied internally and
75  * must remain available until the list is freed with got_pathlist_free().
76  * If the first argument is not NULL, set it to a pointer to the newly inserted
77  * element, or to a NULL pointer in case the path was already on the list.
78  */
79 const struct got_error *got_pathlist_insert(struct got_pathlist_entry **,
80     struct got_pathlist_head *, const char *, void *);
81 
82 /*
83  * Append a path to the list of paths.
84  * The caller should already have initialized the list head. This list stores
85  * the pointer to the path as-is, i.e. the path is not copied internally and
86  * must remain available until the list is freed with got_pathlist_free().
87  */
88 const struct got_error *got_pathlist_append(struct got_pathlist_head *,
89     const char *, void *);
90 
91 /* Free resources allocated for a path list. */
92 void got_pathlist_free(struct got_pathlist_head *);
93 
94 /* Attempt to create a directory at a given path. */
95 const struct got_error *got_path_mkdir(const char *);
96 
97 /* Determine whether a directory has no files or directories in it. */
98 int got_path_dir_is_empty(const char *);
99 
100 /* dirname(3) with error handling and dynamically allocated result. */
101 const struct got_error *got_path_dirname(char **, const char *);
102 
103 /* basename(3) with dynamically allocated result. */
104 const struct got_error *got_path_basename(char **, const char *);
105 
106 /* Strip trailing slashes from a path; path will be modified in-place. */
107 void got_path_strip_trailing_slashes(char *);
108 
109 /* Look up the absolute path of a program in $PATH */
110 const struct got_error *got_path_find_prog(char **, const char *);
111 
112 /* Create a new file at a specified path, with optional content. */
113 const struct got_error *got_path_create_file(const char *, const char *);