[mdlug] grep bug?

[Wojtak, Greg]

This does not occur on RHEL 5.1.  

[root at ql1mgt2 push]# grep -V
grep (GNU grep) 2.5.1

[root at ql1mgt2 push]# rpm -q grep
grep-2.5.1-54.2.el5



-----Original Message-----
From: mdlug-bounces at mdlug.org [mailto:mdlug-bounces at mdlug.org] On Behalf
Of Robert Citek
Sent: Wednesday, April 16, 2008 4:34 PM
To: MDLUG's Main discussion list
Subject: [mdlug] grep bug?

Hello all,

I was running grep on my Ubuntu 7.10 box the other day and came across
some rather bizarre behaviour.  If I ran this grep command, everything
worked just fine:

$ echo hello | grep --color=always -e ^

However, if I make grep case-insensitive, grep seems to hang:

$ echo hello | grep -i --color=always -e ^

A little sleuthing suggests that grep is stuck in some kind of infinite
loop:

$ echo hello | grep -i --color=always -e ^ | hexdump -C | head -3
00000000  1b 5b 30 31 3b 33 31 6d  1b 5b 30 30 6d 1b 5b 30
|.[01;31m.[00m.[0|
00000010  31 3b 33 31 6d 1b 5b 30  30 6d 1b 5b 30 31 3b 33
|1;31m.[00m.[01;3|
00000020  31 6d 1b 5b 30 30 6d 1b  5b 30 31 3b 33 31 6d 1b
|1m.[00m.[01;31m.|

$ grep -V | head -1
grep (GNU grep) 2.5.1

I was wondering if folks here could confirm this behaviour on their
boxes, especially on non-Ubuntu 7.10 installs.  Here it is in script
form:

$ true && (
echo hello | grep --color=always -e ^ | hexdump -C | head -1
echo hello | grep -i --color=always -e ^ | hexdump -C | head -1
)

If I run the above I get this output:

00000000  68 65 6c 6c 6f 0a                                 |hello.|
00000000  1b 5b 30 31 3b 33 31 6d  1b 5b 30 30 6d 1b 5b 30
|.[01;31m.[00m.[0|

I would imagine that on non-affected systems one would get two lines
with "hello".

Thanks in advance for your help.

Regards,
- Robert
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