From 08040f2236bc1919779be958568c1068a139f96d Mon Sep 17 00:00:00 2001
From: Dong Heng <dongheng@espressif.com>
Date: Wed, 6 Nov 2019 15:51:59 +0800
Subject: [PATCH] fix(lwip): fix lacking of gcc header file declare when enable
 VFS

---
 components/lwip/apps/ping/ping.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/components/lwip/apps/ping/ping.c b/components/lwip/apps/ping/ping.c
index 8b8d5512..61245b05 100644
--- a/components/lwip/apps/ping/ping.c
+++ b/components/lwip/apps/ping/ping.c
@@ -57,6 +57,10 @@
 #include "lwip/inet.h"
 #endif /* PING_USE_SOCKETS */
 
+#ifdef CONFIG_USING_ESP_VFS
+#include <unistd.h>
+#endif
+
 #ifdef ESP_PING
 #include "esp_ping.h"
 #include "lwip/ip_addr.h"