+static struct tree_entry_list *find_entry(const char *path, char *pathbuf)
+{
+ const char *next, *slash;
+ int len;
+ struct tree_entry_list *elem = &root_entry, *oldelem = NULL;
+
+ *(pathbuf) = '\0';
+
+ /* Find tree element, descending from root, that
+ * corresponds to the named path, lazily expanding
+ * the tree if possible.
+ */
+
+ while (path) {
+ /* The fact we still have path means that the caller
+ * wants us to make sure that elem at this point is a
+ * directory, and possibly descend into it. Even what
+ * is left is just trailing slashes, we loop back to
+ * here, and this call to prepare_children() will
+ * catch elem not being a tree. Nice.
+ */
+ if (prepare_children(elem))
+ return NULL;
+
+ slash = strchr(path, '/');
+ if (!slash) {
+ len = strlen(path);
+ next = NULL;
+ }
+ else {
+ next = slash + 1;
+ len = slash - path;
+ }
+ if (len) {
+ if (oldelem) {
+ pathbuf += sprintf(pathbuf, "%s/", oldelem->name);
+ }
+
+ /* (len == 0) if the original path was "drivers/char/"
+ * and we have run already two rounds, having elem
+ * pointing at the drivers/char directory.
+ */
+ elem = elem->item.tree->entries;
+ while (elem) {
+ if ((strlen(elem->name) == len) &&
+ !strncmp(elem->name, path, len)) {
+ /* found */
+ break;
+ }
+ elem = elem->next;
+ }
+ if (!elem)
+ return NULL;
+
+ oldelem = elem;
+ }
+ path = next;
+ }
+
+ return elem;
+}
+
+static const char *entry_type(struct tree_entry_list *e)
+{
+ return (e->directory ? "tree" : "blob");
+}
+
+static const char *entry_hex(struct tree_entry_list *e)
+{
+ return sha1_to_hex(e->directory
+ ? e->item.tree->object.sha1
+ : e->item.blob->object.sha1);
+}
+
+/* forward declaration for mutually recursive routines */
+static int show_entry(struct tree_entry_list *, int, char *pathbuf);
+
+static int show_children(struct tree_entry_list *e, int level, char *pathbuf)
+{
+ int oldlen = strlen(pathbuf);
+
+ if (e != &root_entry)
+ sprintf(pathbuf + oldlen, "%s/", e->name);
+
+ if (prepare_children(e))
+ die("internal error: ls-tree show_children called with non tree");
+ e = e->item.tree->entries;
+ while (e) {
+ show_entry(e, level, pathbuf);
+ e = e->next;
+ }
+
+ pathbuf[oldlen] = '\0';
+
+ return 0;
+}
+
+static int show_entry(struct tree_entry_list *e, int level, char *pathbuf)
+{
+ int err = 0;
+
+ if (e != &root_entry) {
+ printf("%06o %s %s ",
+ e->mode, entry_type(e), entry_hex(e));
+ write_name_quoted(pathbuf, e->name, line_termination, stdout);
+ putchar(line_termination);
+ }
+
+ if (e->directory) {
+ /* If this is a directory, we have the following cases:
+ * (1) This is the top-level request (explicit path from the
+ * command line, or "root" if there is no command line).
+ * a. Without any flag. We show direct children. We do not
+ * recurse into them.
+ * b. With -r. We do recurse into children.
+ * c. With -d. We do not recurse into children.
+ * (2) We came here because our caller is either (1-a) or
+ * (1-b).
+ * a. Without any flag. We do not show our children (which
+ * are grandchildren for the original request).
+ * b. With -r. We continue to recurse into our children.
+ * c. With -d. We should not have come here to begin with.
+ */
+ if (level == 0 && !(ls_options & LS_TREE_ONLY))
+ /* case (1)-a and (1)-b */
+ err = err | show_children(e, level+1, pathbuf);
+ else if (level && ls_options & LS_RECURSIVE)
+ /* case (2)-b */
+ err = err | show_children(e, level+1, pathbuf);
+ }
+ return err;
+}
+
+static int list_one(const char *path)
+{
+ int err = 0;
+ char pathbuf[MAXPATHLEN + 1];
+ struct tree_entry_list *e = find_entry(path, pathbuf);
+ if (!e) {
+ /* traditionally ls-tree does not complain about
+ * missing path. We may change this later to match
+ * what "/bin/ls -a" does, which is to complain.
+ */
+ return err;
+ }
+ err = err | show_entry(e, 0, pathbuf);
+ return err;
+}
+
+static int list(char **path)
+{
+ int i;
+ int err = 0;
+ for (i = 0; path[i]; i++)
+ err = err | list_one(path[i]);
+ return err;
+}
+
+static const char ls_tree_usage[] =
+ "git-ls-tree [-d] [-r] [-z] <tree-ish> [path...]";
+