From 411ce63e597b04ffe79478758e272d555965459e Mon Sep 17 00:00:00 2001 From: Assaf Gordon Date: Mon, 11 Apr 2016 02:03:49 -0400 Subject: [PATCH] grep: silently ignore EPIPE errors MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If SIGPIPE is set to 'ignore', exit silently instead of reporting 'write error: Broken pipe' - closely mimicking default SIGPIPE behaviour. Based on similar method in coreutils' seq by Pádraig Brady (http://lists.gnu.org/archive/html/coreutils/2016-04/msg00004.html). * src/grep.c: (prline): if errno=EPIPE, exit silently signalling success instead of reporting write error. * tests/write-error-msg: test with SIGPIPE set to 'ignore'. --- src/grep.c | 7 ++++++- tests/write-error-msg | 10 +++++++++- 2 files changed, 15 insertions(+), 2 deletions(-) diff --git a/src/grep.c b/src/grep.c index 8baca5a..f375ab6 100644 --- a/src/grep.c +++ b/src/grep.c @@ -1235,7 +1235,12 @@ prline (char *beg, char *lim, char sep) fflush_errno (); if (stdout_errno) - error (EXIT_TROUBLE, stdout_errno, _("write error")); + { + if (stdout_errno!=EPIPE) + error (EXIT_TROUBLE, stdout_errno, _("write error")); + /* silently ignore EPIPE errors and exit */ + exit (EXIT_SUCCESS); + } lastout = lim; } diff --git a/tests/write-error-msg b/tests/write-error-msg index 130648b..b56f233 100755 --- a/tests/write-error-msg +++ b/tests/write-error-msg @@ -1,5 +1,6 @@ #!/bin/sh -# Ensure that output errors are reported with errno information. +# Ensure that output errors are reported with errno information, +# except SIGPIPE which is silently ignored. # Copyright 2016 Free Software Foundation, Inc. @@ -52,4 +53,11 @@ done compare err1 err2 \ || { warn_ "err1,err2 contain different error messages" ; fail=1 ; } + +# With SIGPIPE ignored, grep should detect EPIPE, yet exit silently. +( trap '' PIPE ; + sh -c 'grep --line-buffered 1 err3 | head -n1 >/dev/null' ) \ + || framework_failure_ +compare /dev/null err3 || fail=1 + Exit $fail -- 2.7.0