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_IFREG | \
20 	S_IRUSR|S_IWUSR | S_IRGRP | S_IROTH)
21 #define GOT_DEFAULT_DIR_MODE	(S_IFDIR | \
22 	S_IRWXU | S_IRGRP|S_IXGRP | S_IROTH|S_IXOTH)
23 
24 /* Determine whether a path is an absolute path. */
25 int got_path_is_absolute(const char *);
26 
27 /*
28  * Return an absolute version of a relative path.
29  * The result is allocated with malloc(3).
30  */
31 char *got_path_get_absolute(const char *);
32 
33 /*
34  * Canonicalize absolute paths by removing redundant path separators
35  * and resolving references to parent directories ("/../").
36  * Relative paths are copied from input to buf as-is.
37  */
38 const struct got_error *got_canonpath(const char *, char *, size_t);
39 
40 /*
41  * Get child part of two absolute paths. The second path must equal the first
42  * path up to some path component, and must be longer than the first path.
43  * The result is allocated with malloc(3).
44  */
45 const struct got_error *got_path_skip_common_ancestor(char **, const char *,
46     const char *);
47 
48 /* Determine whether a path points to the root directory "/" . */
49 int got_path_is_root_dir(const char *);
50 
51 /* Determine whether a path is a path-wise child of another path. */
52 int got_path_is_child(const char *, const char *, size_t);
53 
54 /*
55  * Like strcmp() but orders children in subdirectories directly after
56  * their parents. String lengths must also be passed in.
57  */
58 int got_path_cmp(const char *, const char *, size_t, size_t);
59 
60 /*
61  * Path lists allow for predictable concurrent iteration over multiple lists
62  * of paths obtained from disparate sources which don't all provide the same
63  * ordering guarantees (e.g. git trees, file index, and on-disk directories).
64  */
65 struct got_pathlist_entry {
66 	TAILQ_ENTRY(got_pathlist_entry) entry;
67 	const char *path;
68 	size_t path_len;
69 	void *data; /* data pointer provided to got_pathlist_insert() */
70 };
71 TAILQ_HEAD(got_pathlist_head, got_pathlist_entry);
72 
73 /*
74  * Insert a path into the list of paths in a predictable order.
75  * The caller should already have initialized the list head. This list stores
76  * the pointer to the path as-is, i.e. the path is not copied internally and
77  * must remain available until the list is freed with got_pathlist_free().
78  * If the first argument is not NULL, set it to a pointer to the newly inserted
79  * element, or to a NULL pointer in case the path was already on the list.
80  */
81 const struct got_error *got_pathlist_insert(struct got_pathlist_entry **,
82     struct got_pathlist_head *, const char *, void *);
83 
84 /*
85  * Append a path to the list of paths.
86  * The caller should already have initialized the list head. This list stores
87  * the pointer to the path as-is, i.e. the path is not copied internally and
88  * must remain available until the list is freed with got_pathlist_free().
89  */
90 const struct got_error *got_pathlist_append(struct got_pathlist_head *,
91     const char *, void *);
92 
93 /* Free resources allocated for a path list. */
94 void got_pathlist_free(struct got_pathlist_head *);
95 
96 /* Attempt to create a directory at a given path. */
97 const struct got_error *got_path_mkdir(const char *);
98 
99 /* Determine whether a directory has no files or directories in it. */
100 int got_path_dir_is_empty(const char *);
101 
102 /* dirname(3) with error handling and dynamically allocated result. */
103 const struct got_error *got_path_dirname(char **, const char *);
104 
105 /* basename(3) with dynamically allocated result. */
106 const struct got_error *got_path_basename(char **, const char *);
107 
108 /* Strip trailing slashes from a path; path will be modified in-place. */
109 void got_path_strip_trailing_slashes(char *);
110 
111 /* Look up the absolute path of a program in $PATH */
112 const struct got_error *got_path_find_prog(char **, const char *);
113 
114 /* Create a new file at a specified path, with optional content. */
115 const struct got_error *got_path_create_file(const char *, const char *);