Split the libfstree add_by_path tree traversal function out

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 76 insertions, 0 deletions

diff --git a/lib/fstree/get_by_path.c b/lib/fstree/get_by_path.c
new file mode 100644
index 0000000..8742892
--- /dev/null
+++ b/lib/fstree/get_by_path.c
@@ -0,0 +1,76 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * get_by_path.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "config.h"
+
+#include "fstree.h"
+
+#include <string.h>
+#include <errno.h>
+
+static tree_node_t *child_by_name(tree_node_t *root, const char *name,
+				  size_t len)
+{
+	tree_node_t *n = root->data.dir.children;
+
+	while (n != NULL) {
+		if (strncmp(n->name, name, len) == 0 && n->name[len] == '\0')
+			break;
+
+		n = n->next;
+	}
+
+	return n;
+}
+
+tree_node_t *fstree_get_node_by_path(fstree_t *fs, tree_node_t *root,
+				     const char *path, bool create_implicitly,
+				     bool stop_at_parent)
+{
+	const char *end;
+	tree_node_t *n;
+	size_t len;
+
+	while (*path != '\0') {
+		while (*path == '/')
+			++path;
+
+		if (!S_ISDIR(root->mode)) {
+			errno = ENOTDIR;
+			return NULL;
+		}
+
+		end = strchr(path, '/');
+		if (end == NULL) {
+			if (stop_at_parent)
+				break;
+
+			len = strlen(path);
+		} else {
+			len = end - path;
+		}
+
+		n = child_by_name(root, path, len);
+
+		if (n == NULL) {
+			if (!create_implicitly) {
+				errno = ENOENT;
+				return NULL;
+			}
+
+			n = fstree_mknode(root, path, len, NULL, &fs->defaults);
+			if (n == NULL)
+				return NULL;
+
+			n->data.dir.created_implicitly = true;
+		}
+
+		root = n;
+		path = path + len;
+	}
+
+	return root;
+}