On 4/20/19 4:41 AM, 積丹尼 Dan Jacobson wrote:
‘--line-buffered’ Use line buffering on output. This can cause a performance penalty.OK, but say what will happen if one doesn't use this. Paragraph buffering? Page buffering?
Thanks for mentioning this. I installed the attached patch to try to clarify this point.
>From 2508eb94fbd01c73f78f742b61953fdf938acf4b Mon Sep 17 00:00:00 2001 From: Paul Eggert <[email protected]> Date: Tue, 22 Sep 2020 10:56:29 -0700 Subject: [PATCH] doc: improve --line-buffer doc * doc/grep.texi (Other Options): Document --line-buffered more carefully, and say what happens when it is not used. Problem reported by Dan Jacobson (Bug#35339). --- doc/grep.texi | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/doc/grep.texi b/doc/grep.texi index 15185f3..bb76ae1 100644 --- a/doc/grep.texi +++ b/doc/grep.texi @@ -771,8 +771,11 @@ and @file{file2}. @item --line-buffered @opindex --line-buffered @cindex line buffering -Use line buffering on output. -This can cause a performance penalty. +Use line buffering for standard output, regardless of output device. +By default, standard output is line buffered for interactive devices, +and is fully buffered otherwise. With full buffering, the output +buffer is flushed when full; with line buffering, the buffer is also +flushed after every output line. The buffer size is system dependent. @item -U @itemx --binary -- 2.17.1
