While hacking on pg_rewind, this in pg_rewind's main() function caught
my eye:
progress_report(true);
printf("\n");
It is peculiar, because progress_report() uses fprintf(stderr, ...) for
all its printing, and in fact the only other use of printf() in
pg_rewind is in printing the "pg_rewind --help" text.
I think the idea here was to move to the next line, after
progress_report() has updated the progress line for the last time. It
probably also should not be printed, when "--progress" is not used.
Attached is a patch to fix this, as well as a similar issue in
pg_checksums. pg_basebackup and pgbench also print progres reports like
this, but they seem correct to me.
- Heikki
>From b4a64c3aca7257336c3ca1bf4bee8675e148de10 Mon Sep 17 00:00:00 2001
From: Heikki Linnakangas <heikki.linnakan...@iki.fi>
Date: Wed, 12 Aug 2020 23:27:01 +0300
Subject: [PATCH 1/1] Fix printing last progress report line in client
programs.
A number of client programs have a "--progress" option that when printing
to a TTY, updates the current line by printing a '\r' and overwriting it.
After the last line, an extra '\n' needs to be printed to move the cursor
to the next line. pg_basebackup and pgbench got this right, but pg_rewind
and pg_checksums were slightly wrong. pg_rewind printed the newline to
stdout instead of stderr, and pg_checksum printed the newline even when
not printing to a TTY. Fix them.
---
src/bin/pg_checksums/pg_checksums.c | 3 ++-
src/bin/pg_rewind/pg_rewind.c | 3 ++-
2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/src/bin/pg_checksums/pg_checksums.c b/src/bin/pg_checksums/pg_checksums.c
index 1daa5aed0e0..9ae884897ef 100644
--- a/src/bin/pg_checksums/pg_checksums.c
+++ b/src/bin/pg_checksums/pg_checksums.c
@@ -626,7 +626,8 @@ main(int argc, char *argv[])
if (showprogress)
{
progress_report(true);
- fprintf(stderr, "\n"); /* Need to move to next line */
+ if (isatty(fileno(stderr)))
+ fprintf(stderr, "\n"); /* Need to move to next line */
}
printf(_("Checksum operation completed\n"));
diff --git a/src/bin/pg_rewind/pg_rewind.c b/src/bin/pg_rewind/pg_rewind.c
index 0015d3b461a..c000c12fa58 100644
--- a/src/bin/pg_rewind/pg_rewind.c
+++ b/src/bin/pg_rewind/pg_rewind.c
@@ -422,7 +422,8 @@ main(int argc, char **argv)
executeFileMap();
progress_report(true);
- printf("\n");
+ if (showprogress && isatty(fileno(stderr)))
+ fprintf(stderr, "\n"); /* Need to move to next line */
if (showprogress)
pg_log_info("creating backup label and updating control file");
--
2.20.1
