From 02db6d71b67d9efe33292fbf7f92da888aaf879f Mon Sep 17 00:00:00 2001
From: Yousong Zhou <yszhou4tech@gmail.com>
Date: Wed, 17 Feb 2016 15:45:05 +0800
Subject: [PATCH] json_script: add "isdir" support

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>
---
 examples/json_script-example.json |  5 +++++
 json_script.c                     | 26 ++++++++++++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/examples/json_script-example.json b/examples/json_script-example.json
index 45636b7..5328e59 100644
--- a/examples/json_script-example.json
+++ b/examples/json_script-example.json
@@ -27,6 +27,11 @@
     [ "exec_if_or", "%ORVAR%" ]
   ],
 
+  [ "if",
+	[ "isdir", "%ISDIRVAR%" ],
+	[ "exec_isdir", "%ISDIRVAR%" ]
+  ],
+
   [ "return", "foobar" ],
 
   [ "exec_non_reachable", "Arghhh" ]
diff --git a/json_script.c b/json_script.c
index 7cef481..b5d414d 100644
--- a/json_script.c
+++ b/json_script.c
@@ -32,6 +32,7 @@ struct json_handler {
 
 static int json_process_expr(struct json_call *call, struct blob_attr *cur);
 static int json_process_cmd(struct json_call *call, struct blob_attr *cur);
+static int eval_string(struct json_call *call, struct blob_buf *buf, const char *name, const char *pattern);
 
 struct json_script_file *
 json_script_file_from_blobmsg(const char *name, void *data, int len)
@@ -345,6 +346,30 @@ static int handle_expr_not(struct json_call *call, struct blob_attr *expr)
 	return !ret;
 }
 
+static int handle_expr_isdir(struct json_call *call, struct blob_attr *expr)
+{
+	static struct blob_buf b;
+	struct blob_attr *tb[3];
+	const char *pattern, *path;
+	struct stat s;
+	int ret;
+
+	json_get_tuple(expr, tb, BLOBMSG_TYPE_STRING, 0);
+	if (!tb[1] || blobmsg_type(tb[1]) != BLOBMSG_TYPE_STRING)
+		return -1;
+	pattern = blobmsg_data(tb[1]);
+
+	blob_buf_init(&b, 0);
+	ret = eval_string(call, &b, NULL, pattern);
+	if (ret < 0)
+		return ret;
+	path = blobmsg_data(blob_data(b.head));
+	ret = stat(path, &s);
+	if (ret < 0)
+		return 0;
+	return S_ISDIR(s.st_mode);
+}
+
 static const struct json_handler expr[] = {
 	{ "eq", handle_expr_eq },
 	{ "regex", handle_expr_regex },
@@ -352,6 +377,7 @@ static const struct json_handler expr[] = {
 	{ "and", handle_expr_and },
 	{ "or", handle_expr_or },
 	{ "not", handle_expr_not },
+	{ "isdir", handle_expr_isdir },
 };
 
 static int