From 4511e6c831e3d16303d6df183a00d33f5d6ba3e8 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Wed, 14 May 2014 21:13:56 -0400 Subject: [PATCH] In initdb, ensure stdout/stderr buffering behavior is what we expect. Since this program may print to either stdout or stderr, the relative ordering of its messages depends on the buffering behavior of those files. Force stdout to be line-buffered and stderr to be unbuffered, ensuring that the behavior will match standard Unix interactive behavior, even when stdout and stderr are rerouted to a file. Per complaint from Tomas Vondra. The particular case he pointed out is new in HEAD, but issues of the same sort could arise in any branch with other error messages, so back-patch to all branches. I'm unsure whether we might not want to do this in other client programs as well. For the moment, just fix initdb. --- src/bin/initdb/initdb.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c index c4c79bc807e..e43ad4a6ecd 100644 --- a/src/bin/initdb/initdb.c +++ b/src/bin/initdb/initdb.c @@ -3447,6 +3447,15 @@ main(int argc, char *argv[]) char *effective_user; char bin_dir[MAXPGPATH]; + /* + * Ensure that buffering behavior of stdout and stderr matches what it is + * in interactive usage (at least on most platforms). This prevents + * unexpected output ordering when, eg, output is redirected to a file. + * POSIX says we must do this before any other usage of these files. + */ + setvbuf(stdout, NULL, _IOLBF, 0); + setvbuf(stderr, NULL, _IONBF, 0); + progname = get_progname(argv[0]); set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("initdb"));