From 8e4cbfeea14035483de67de81e2b1ff40390cb8a Mon Sep 17 00:00:00 2001
From: Tomoki Shirasawa <sira@popeye.cc.u-tokyo.ac.jp>
Date: Tue, 10 Dec 2013 14:45:37 +0900
Subject: [PATCH] print exit code or signal, if stderr is a tty

---
 executer/user/mcexec.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/executer/user/mcexec.c b/executer/user/mcexec.c
index 326e1163..a357678e 100644
--- a/executer/user/mcexec.c
+++ b/executer/user/mcexec.c
@@ -920,10 +920,12 @@ int main_loop(int fd, int cpu, pthread_mutex_t *lock)
 			if(w.sr.number == __NR_exit_group){
 				sig = w.sr.args[0] & 0x7f;
 				term = (w.sr.args[0] & 0xff00) >> 8;
-				if(sig)
-					fprintf(stderr, "Terminate by signal %d\n", sig);
-				else if(term)
-					fprintf(stderr, "Exit status: %d\n", term);
+				if(isatty(2)){
+					if(sig)
+						fprintf(stderr, "Terminate by signal %d\n", sig);
+					else if(term)
+						fprintf(stderr, "Exit status: %d\n", term);
+				}
 			}
 
 #ifdef USE_SYSCALL_MOD_CALL