Merge branch 'ma/asciidoctor-more-fixes'
[git/git.git] / dir-iterator.h
1 #ifndef DIR_ITERATOR_H
2 #define DIR_ITERATOR_H
3
4 #include "strbuf.h"
5
6 /*
7 * Iterate over a directory tree.
8 *
9 * Iterate over a directory tree, recursively, including paths of all
10 * types and hidden paths. Skip "." and ".." entries and don't follow
11 * symlinks except for the original path. Note that the original path
12 * is not included in the iteration.
13 *
14 * Every time dir_iterator_advance() is called, update the members of
15 * the dir_iterator structure to reflect the next path in the
16 * iteration. The order that paths are iterated over within a
17 * directory is undefined, directory paths are always given before
18 * their contents.
19 *
20 * A typical iteration looks like this:
21 *
22 * int ok;
23 * unsigned int flags = DIR_ITERATOR_PEDANTIC;
24 * struct dir_iterator *iter = dir_iterator_begin(path, flags);
25 *
26 * if (!iter)
27 * goto error_handler;
28 *
29 * while ((ok = dir_iterator_advance(iter)) == ITER_OK) {
30 * if (want_to_stop_iteration()) {
31 * ok = dir_iterator_abort(iter);
32 * break;
33 * }
34 *
35 * // Access information about the current path:
36 * if (S_ISDIR(iter->st.st_mode))
37 * printf("%s is a directory\n", iter->relative_path);
38 * }
39 *
40 * if (ok != ITER_DONE)
41 * handle_error();
42 *
43 * Callers are allowed to modify iter->path while they are working,
44 * but they must restore it to its original contents before calling
45 * dir_iterator_advance() again.
46 */
47
48 /*
49 * Flags for dir_iterator_begin:
50 *
51 * - DIR_ITERATOR_PEDANTIC: override dir-iterator's default behavior
52 * in case of an error at dir_iterator_advance(), which is to keep
53 * looking for a next valid entry. With this flag, resources are freed
54 * and ITER_ERROR is returned immediately. In both cases, a meaningful
55 * warning is emitted. Note: ENOENT errors are always ignored so that
56 * the API users may remove files during iteration.
57 *
58 * - DIR_ITERATOR_FOLLOW_SYMLINKS: make dir-iterator follow symlinks.
59 * i.e., linked directories' contents will be iterated over and
60 * iter->base.st will contain information on the referred files,
61 * not the symlinks themselves, which is the default behavior. Broken
62 * symlinks are ignored.
63 *
64 * Warning: circular symlinks are also followed when
65 * DIR_ITERATOR_FOLLOW_SYMLINKS is set. The iteration may end up with
66 * an ELOOP if they happen and DIR_ITERATOR_PEDANTIC is set.
67 */
68 #define DIR_ITERATOR_PEDANTIC (1 << 0)
69 #define DIR_ITERATOR_FOLLOW_SYMLINKS (1 << 1)
70
71 struct dir_iterator {
72 /* The current path: */
73 struct strbuf path;
74
75 /*
76 * The current path relative to the starting path. This part
77 * of the path always uses "/" characters to separate path
78 * components:
79 */
80 const char *relative_path;
81
82 /* The current basename: */
83 const char *basename;
84
85 /*
86 * The result of calling lstat() on path; or stat(), if the
87 * DIR_ITERATOR_FOLLOW_SYMLINKS flag was set at
88 * dir_iterator's initialization.
89 */
90 struct stat st;
91 };
92
93 /*
94 * Start a directory iteration over path with the combination of
95 * options specified by flags. On success, return a dir_iterator
96 * that holds the internal state of the iteration. In case of
97 * failure, return NULL and set errno accordingly.
98 *
99 * The iteration includes all paths under path, not including path
100 * itself and not including "." or ".." entries.
101 *
102 * Parameters are:
103 * - path is the starting directory. An internal copy will be made.
104 * - flags is a combination of the possible flags to initialize a
105 * dir-iterator or 0 for default behavior.
106 */
107 struct dir_iterator *dir_iterator_begin(const char *path, unsigned int flags);
108
109 /*
110 * Advance the iterator to the first or next item and return ITER_OK.
111 * If the iteration is exhausted, free the dir_iterator and any
112 * resources associated with it and return ITER_DONE.
113 *
114 * It is a bug to use iterator or call this function again after it
115 * has returned ITER_DONE or ITER_ERROR (which may be returned iff
116 * the DIR_ITERATOR_PEDANTIC flag was set).
117 */
118 int dir_iterator_advance(struct dir_iterator *iterator);
119
120 /*
121 * End the iteration before it has been exhausted. Free the
122 * dir_iterator and any associated resources and return ITER_DONE. On
123 * error, free the dir_iterator and return ITER_ERROR.
124 */
125 int dir_iterator_abort(struct dir_iterator *iterator);
126
127 #endif