On 10/3/20 12:00 PM, John Ruckstuhl wrote:
In egrep (grep 3.0), the order of options (multiple --include and --exclude),
is surprisingly significant.
I was puzzled by 5 extra output lines in my first egrep,
so I did another egrep, with the --include moved up front.
That's expected behavior, but it's not documented and should be. Thanks for
bringing it up. I installed the attached doc patch.
>From ef74f67e27ad76a26670eb5551202bd4b268294d Mon Sep 17 00:00:00 2001
From: Paul Eggert <egg...@cs.ucla.edu>
Date: Sat, 3 Oct 2020 12:41:38 -0700
Subject: [PATCH] doc: document --include/--exclude better
Problem reported by John Ruckstuhl (Bug#43782).
* doc/grep.texi (File and Directory Selection):
Document what happens if contradictory options are given,
or if no option matches a file name.
* doc/grep.in.1:
---
doc/grep.in.1 | 11 +++++++++++
doc/grep.texi | 4 ++++
2 files changed, 15 insertions(+)
diff --git a/doc/grep.in.1 b/doc/grep.in.1
index 91c0bca..7d5dfe5 100644
--- a/doc/grep.in.1
+++ b/doc/grep.in.1
@@ -680,6 +680,17 @@ Search only files whose base name matches
.I GLOB
(using wildcard matching as described under
.BR \-\^\-exclude ).
+If contradictory
+.B \-\^\-include
+and
+.B \-\^\-exclude
+options are given, the last matching one wins.
+If no
+.B \-\^\-include
+or
+.B \-\^\-exclude
+options match, a file is included unless the first such option is
+.BR \-\^\-include .
.TP
.BR \-r ", " \-\^\-recursive
Read all files under each directory, recursively,
diff --git a/doc/grep.texi b/doc/grep.texi
index bb76ae1..0c0bb12 100644
--- a/doc/grep.texi
+++ b/doc/grep.texi
@@ -728,6 +728,10 @@ this is equivalent to the @samp{--binary-files=without-match} option.
@cindex searching directory trees
Search only files whose name matches @var{glob},
using wildcard matching as described under @option{--exclude}.
+If contradictory @option{--include} and @option{--exclude} options are
+given, the last matching one wins. If no @option{--include} or
+@option{--exclude} options match, a file is included unless the first
+such option is @option{--include}.
@item -r
@itemx --recursive
--
2.25.1
