From 46e358158109200abde4de0a044a415c80c9bce5 Mon Sep 17 00:00:00 2001 From: Johannes Sixt Date: Thu, 26 Apr 2012 23:00:39 +0200 Subject: [PATCH] t5570: fix forwarding of git-daemon messages via cat The shell function that starts git-daemon wants to read the first line of the daemon's stderr to ensure that it started correctly. Subsequent daemon errors should be redirected to fd 4 (which is the terminal in verbose mode or /dev/null in quiet mode). To that end the shell script used 'read' to get the first line of output, and then 'cat &' to forward everything else in a background process. The problem is, that 'cat >&4 &' does not produce any output because the shell redirects a background process's stdin to /dev/null. To have this command invocation do anything useful, we have to redirect its stdin explicitly (which overrides the /dev/null redirection). The shell function connects the daemon's stderr to its consumers via a FIFO. We cannot just do this: read line &4 & because after the first redirection the pipe is closed and the daemon could receive SIGPIPE if it writes at the wrong moment. Therefore, we open the readable end of the FIFO only once on fd 7 in the shell and dup from there to the stdin of the two consumers. Signed-off-by: Johannes Sixt Acked-by: Jeff King Signed-off-by: Junio C Hamano --- t/lib-git-daemon.sh | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/t/lib-git-daemon.sh b/t/lib-git-daemon.sh index ef2d01f369..87f0ad8f41 100644 --- a/t/lib-git-daemon.sh +++ b/t/lib-git-daemon.sh @@ -31,19 +31,19 @@ start_git_daemon() { >&3 2>git_daemon_output & GIT_DAEMON_PID=$! { - read line + read line <&7 echo >&4 "$line" - cat >&4 & + cat <&7 >&4 & + } 7