From 89826f41bd5c96e6b13692d03d08049c912b9365 Mon Sep 17 00:00:00 2001
From: Frans Kaashoek <kaashoek@mit.edu>
Date: Mon, 19 Sep 2016 07:01:30 -0400
Subject: [PATCH] Check result of write (thans to Alexander Kapshuk
 <alexander.kapshuk@gmail)

---
 cat.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/cat.c b/cat.c
index 2b2dcc7..5ddc820 100644
--- a/cat.c
+++ b/cat.c
@@ -9,8 +9,12 @@ cat(int fd)
 {
   int n;
 
-  while((n = read(fd, buf, sizeof(buf))) > 0)
-    write(1, buf, n);
+  while((n = read(fd, buf, sizeof(buf))) > 0) {
+    if (write(1, buf, n) != n) {
+      printf(1, "cat: write error\n");
+      exit();
+    }
+  }
   if(n < 0){
     printf(1, "cat: read error\n");
     exit();