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  *     struct dir_iterator *iter = dir_iterator_begin(path);
  24  *
  25  *     if (!iter)
  26  *             goto error_handler;
  27  *
  28  *     while ((ok = dir_iterator_advance(iter)) == ITER_OK) {
  29  *             if (want_to_stop_iteration()) {
  30  *                     ok = dir_iterator_abort(iter);
  31  *                     break;
  32  *             }
  33  *
  34  *             // Access information about the current path:
  35  *             if (S_ISDIR(iter->st.st_mode))
  36  *                     printf("%s is a directory\n", iter->relative_path);
  37  *     }
  38  *
  39  *     if (ok != ITER_DONE)
  40  *             handle_error();
  41  *
  42  * Callers are allowed to modify iter->path while they are working,
  43  * but they must restore it to its original contents before calling
  44  * dir_iterator_advance() again.
  45  */
  46
  47 struct dir_iterator {
  48         /* The current path: */
  49         struct strbuf path;
  50
  51         /*
  52          * The current path relative to the starting path. This part
  53          * of the path always uses "/" characters to separate path
  54          * components:
  55          */
  56         const char *relative_path;
  57
  58         /* The current basename: */
  59         const char *basename;
  60
  61         /* The result of calling lstat() on path: */
  62         struct stat st;
  63 };
  64
  65 /*
  66  * Start a directory iteration over path. On success, return a
  67  * dir_iterator that holds the internal state of the iteration.
  68  * In case of failure, return NULL and set errno accordingly.
  69  *
  70  * The iteration includes all paths under path, not including path
  71  * itself and not including "." or ".." entries.
  72  *
  73  * path is the starting directory. An internal copy will be made.
  74  */
  75 struct dir_iterator *dir_iterator_begin(const char *path);
  76
  77 /*
  78  * Advance the iterator to the first or next item and return ITER_OK.
  79  * If the iteration is exhausted, free the dir_iterator and any
  80  * resources associated with it and return ITER_DONE. On error, free
  81  * dir_iterator and associated resources and return ITER_ERROR. It is
  82  * a bug to use iterator or call this function again after it has
  83  * returned ITER_DONE or ITER_ERROR.
  84  */
  85 int dir_iterator_advance(struct dir_iterator *iterator);
  86
  87 /*
  88  * End the iteration before it has been exhausted. Free the
  89  * dir_iterator and any associated resources and return ITER_DONE. On
  90  * error, free the dir_iterator and return ITER_ERROR.
  91  */
  92 int dir_iterator_abort(struct dir_iterator *iterator);
  93
  94 #endif