grep与zgrep多个文件的退出状态差异

Question

设置

echo "abc" >/tmp/foo1
echo "def" >/tmp/foo2
cp /tmp/foo1 /tmp/gzfoo1
cp /tmp/foo2 /tmp/gzfoo2
gzip /tmp/gzfoo*

多个文件的grep退出状态，一个匹配为0。

grep -q abc /tmp/foo[12]
echo $?
0

具有多个解压缩文件且匹配为1的zgrep退出状态

zgrep -q abc /tmp/foo[12]
echo $?
1

具有多个压缩文件且匹配为1的zgrep退出状态

zgrep -q abc /tmp/gzfoo[12].gz
echo $?
1

我确实看到zgrep是一个shell脚本。看起来，如果任何grep返回非零，zgrep也返回非零。以下是我从zgrep摘录的译文：

res=0
for input_file
do
  # ... run grep on input_file ...
  r=$?
  ...
  test $res -lt $r && res=$r
done
exit $res

zgrep版本为(古) 1.3.12：

$ zgrep --version
zgrep (gzip) 1.3.12
Copyright (C) 2007 Free Software Foundation, Inc.
This is free software.  You may redistribute copies of it under the terms of
the GNU General Public License .
There is NO WARRANTY, to the extent permitted by law.

Written by Jean-loup Gailly.

zgrep (gzip) 1.6也会发生：

$ /.
There is NO WARRANTY, to the extent permitted by law.

Written by Jean-loup Gailly.

$ /

问题: zgrep中有bug吗？应该修好吗？

编辑:使用zgrep/gzip 1.8找到了一台更新的机器，它没有这个问题。看来我的机器太旧了。下面是它在新机器上的样子：

: zgrep --version
zgrep (gzip) 1.8
Copyright (C) 2010-2016 Free Software Foundation, Inc.
This is free software.  You may redistribute copies of it under the terms of
the GNU General Public License .
There is NO WARRANTY, to the extent permitted by law.

Written by Jean-loup Gailly.

: zgrep -q abc /tmp/foo[12]
: echo $?
0

为了避免旧的/错误的zgrep，你要做些简单的解决办法：

: ( gzcat -f /tmp/foo[12] | grep -q abc ) >&/dev/null 
: echo $?
0

Answer 1

您可以从https://savannah.gnu.org/git/?group=gzip获得源代码。在提交d2a1928e5534017456dc8a3b600ba0b30cce4a6e中更改了返回代码：

commit d2a1928e5534017456dc8a3b600ba0b30cce4a6e
Author: Paul Eggert 
Date:   Thu Jun 12 18:43:08 2014 -0700

    zgrep: exit with status 0 if a file matches and there's no trouble

    Reported by Pavel Raiskup in: http://bugs.gnu.org/17760
    * zgrep.in (res): Treat exit status 0 to be greater than 1.
    Also, exit immediately on software configuration error.

提交消息包含一个指向错误报告的链接：https://debbugs.gnu.org/cgi/bugreport.cgi?bug=17760

你可以自己检查一下。使用上述提交构建的zgrep：

$ /media/data/gzip-install-newer/bin/zgrep --version
zgrep (gzip) 1.6.17-d2a1
Copyright (C) 2010-2014 Free Software Foundation, Inc.
This is free software.  You may redistribute copies of it under the terms of
the GNU General Public License .
There is NO WARRANTY, to the extent permitted by law.

Written by Jean-loup Gailly.
$ /media/data/gzip-install-newer/bin/zgrep -q abc /tmp/foo[12]
$ echo $?
0

使用上一次提交构建的zgrep：

$ /media/data/gzip-install/bin/zgrep --version
zgrep (gzip) 1.6.16-ed8c
Copyright (C) 2010-2014 Free Software Foundation, Inc.
This is free software.  You may redistribute copies of it under the terms of
the GNU General Public License .
There is NO WARRANTY, to the extent permitted by law.

Written by Jean-loup Gailly.
$ /media/data/gzip-install/bin/zgrep -q abc /tmp/foo[12]
$ echo $?
1