topic Re: Error in user setting making grep behave badly in Operating System - HP-UX

Error in user setting making grep behave badly

Charles Frenette — Thu, 06 Jul 2006 15:28:22 GMT

HI,
I have an unexpected behaviour for one particular user on my HP-US 11i system
The following command: echo 7 | grep [0-9] is not working properly in a script or on the prompt.
example:
maestro@[dm3czo]echo 7 | grep [0-9]
1: TERM=vt100
1: MAESTROLINES=0
1: PATH=$PATH:/bin:/usr/bin:/usr/local/bin:/opt/maestro:/opt/maestro/bin:.:/opt/syncsort380/lib:/stage/syncsort350/lib ; export PATH
1:SHLIB_PATH=/opt/syncsort/lib:/opt/syncsort380/lib/:/stage/syncsort350/lib; export SHLIB_PATH
1: trap "echo 'logout'" 0
1: umask 007
1:tput sgr0
1:tput sgr0

This is like the content of the .profile is passed to the grep command.

But this command is working just fine for others user:

cfrenett@dm3czo:/home/cfrenett>echo 7 | grep [0-9]
7

I have try to locate the difference in the settings of theses users and I cannot find any major differences.
Do you have an idea where I can look to correct this problem?
Thanks,
Charles.

Re: Error in user setting making grep behave badly

Mel Burslan — Thu, 06 Jul 2006 16:08:00 GMT

echo 7 command converting itself to env output did not make much sense, but chek to see if the shells of the two users are the same.

Re: Error in user setting making grep behave badly

A. Clay Stephenson — Thu, 06 Jul 2006 16:09:19 GMT

Grep is behaving exactly as it is supposed to; you scripting is sloppy because consider the case when there is a file (or files) "0" - "9" in the current working directory. The shell dutifully expands your pattern and supplies them as your argument to grep.

The fix is quite simple
echo 7 | grep '[0-9]'

although a more rigourous test would also anchor the target pattern:

echo "7" | grep -E '^[0-9]$'

This will only match a single digit.

Re: Error in user setting making grep behave badly

Bill Hassell — Thu, 06 Jul 2006 16:19:25 GMT

Start with verifying the actual commands:

type grep
type echo
type 7

The type command (actually whence -v) tells you what the string will produce when the shell sees that string. The results should be:

> grep is a tracked alias for /usr/bin/grep
> echo is a shell builtin.
> 7 not found.

then look at the environment by typing the commands:

alias
set

Look for strange character strings in the alias and set commands.

BTW: the PATH statement has several concerns:

/bin hasn't existed for more than a dozen years. The correct path is /usr/bin. /bin is a temporary transition link.

/usr/local/bin should be checked for the correct permissions. The default is 777 which is unacceptable for PATH usage. Make sure /usr/local/bin is 775 or 755.

:.: is in the path. All seasoned admins will agree that having . (the current working directory) is a bad security risk.

Re: Error in user setting making grep behave badly

Peter Nikitka — Fri, 07 Jul 2006 06:33:19 GMT

Hi,

Clay's response (matching a filename surely put you to the cause of your problem. I want to add:
- your problem is NOT user specific - if you change to the path, where the command was called by that user, every user with read acces to that directory would get that result.
- to get an exact match, you can use
echo 7 | grep -x '[0-9]'
The option '-x' anchors your pattern at the beginning and at the end of a line lile '^[0-9]$' but is valid for the whole match:
egrep -x '[0-9]|aa' matches a line containing exactly one digit or a single 'aa'.

mfG Peter

Re: Error in user setting making grep behave badly

Charles Frenette — Fri, 07 Jul 2006 08:12:59 GMT

Thanks to all of you.
The problem was that a file 1 was existing in the home of that user and contains the output of the env commant.
And the correction to the grep resolve my issue.

Thanks again.
Charles.