From b9f68b17b47f5ee2128d75e8483853d4e3224d30 Mon Sep 17 00:00:00 2001
From: ruanyf <yifeng.ruan@gmail.com>
Date: Sun, 24 Oct 2021 07:47:07 +0800
Subject: [PATCH] docs(file): fixed #51

---
 docs/file.md | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/docs/file.md b/docs/file.md
index a7d508a..12ed7ee 100644
--- a/docs/file.md
+++ b/docs/file.md
@@ -21,12 +21,19 @@ FILE* fp;
 
 int main(void) {
   FILE* fp;
-  fp = fopen("hello.txt", "r");
+  char c;
 
-  char c = fgetc(fp);
+  fp = fopen("hello.txt", "r");
+  if (fp == NULL) {
+    return -1;
+  }
+
+  c = fgetc(fp);
   printf("%c\n", c);
 
   fclose(fp);
+
+  return 0;
 }
 ```