egrep with variable on input

[Leo The Cat]

Hi

This is not correct
if [[ $(echo $TNSSTRING | egrep -i (ORA-01|ORA-27) | wc -l) -gt 0 ]]; then


How to use the $TNSSTRING variable as a file for egrep ?

Bests regards
Den

[Steven Schweda]

> How to use the $TNSSTRING variable as a
> file for egrep ?

What does this mean? Does TNSSTRING contain
a file name, or does it contain the data
which you are trying to search?

One line out of a bigger script does not tell
me as much as you might hope that it does.

What does
echo $TNSSTRING
give you?

Where are the data which you are trying to
search?

Better still: What are you trying to do?

It may make more sense to find a better
solution to the actual problem than it does
to try to fix some sub-ideal scheme. But,
because my psychic powers are so weak, this
would require you to describe the actual
problem.

[Leo The Cat]

$TNSSTRING contains more than one lines !

Here an Example of result with $TNSSTRING = SQL*Plus: Release 10.2.0.1.0 - Production on Wed Sep 9 11:24:10 2009 Copyright (c) 1982, 2005, Oracle. All rights reserved. ERROR: ORA-12154: TNS:could not resolve the connect identifier specified SP2
-0751: Unable to connect to Oracle. Exiting SQL*Plus

The errors come because we have a ( character in the input data ...

oas_check_sqlnet.ksh[81]: 0403-057 Syntax error at line 1 : `(' is not expected.

Bests Regards
Den

[Leo The Cat]

Of course I could create a file first in /tmp and use it as input after but it's not very nice !
...

[macosta]

I would remove the parens around the egrep pattern. Try writing it as:
egrep -i 'ORA-01|ORA-27'

You'll probably also want to put double-quotes around "$TNSSTRING" when you use it, since there's a line break and spaces in it - never assume your input will look the same every time.

Another thing, is instead of invoking "wc" to count, try using the "-q" option to egrep, then check the return code with the "$?" variable or using || and/or && operators to handle the various cases.

For example:
--
$ t="this is a string"
$ echo $t | egrep -iq 'STRING'
$ echo $?
0
$ echo $t | egrep -iq 'STRONG'
$ echo $?
1
$ echo $t | egrep -iq 'STRING' && echo Match
Match
$ echo $t | egrep -iq 'STRONG' || echo No match
No match
--

Any POSIX shell should handle this, such as ksh and bash.

[Leo The Cat]

Hi Macosta

The problem is not with egrep -i (ORA-01|ORA-27)

BUT

With "(" inside variables ;-)

Try your example with t="this is () a problem" and this will break your idea.

!!!

Bests Regards
Den

[Steven Schweda]

> With "(" inside variables ;-)

Perhaps you could provide some simple test
case which would show us exactly what you
think this problem is. I know of no
particular shell problem with "(" (or ")")
in a variable's value. For example:


bash$ t='abc
> a(b)c
> xyz'
bash$ echo "$t"
abc
a(b)c
xyz
bash$ echo "$t" | grep b
abc
a(b)c

I see what I expect.

You may have a problem somewhere in your
(complex) procedure which does some Oracle
magic, but I don't think that you know what
the problem is, or where it is. And it's
easier to see these things when you look at
smaller bits.

> The errors come because [...]

Who is complaining? What did he see? Who
sent him that stuff?

[macosta]

Leo, please at try my suggestions before disagreeing with them. If you had done so, we'd be done here.

Quote your variables and replace the un-escaped parens in the egrep statement.

--
$ t="()()()()()()(())((()))"
$ echo $"t" | egrep -i (nope|nothere)
bash: syntax error near unexpected token `('
$ echo $"t" | egrep -i 'nope|nothere'
$ echo "$t" | egrep -i 'nope|()'
()()()()()()(())((()))
--

The shell is trying to interpret the parens before it even tries to run the egrep command. It's not the variable contents.

[Roland Piette]

Hello

(ORA-01|ORA-27) expression contains '|' wich is piping character. So when the shell interpret this string the ( char is not balanced!

I don't understand the () !
If you try to use | as or bitwise operator between two strings your syntax needs to be egrep -i "ORA-01|ORA-27"

Regards,
Roland

[James R. Ferguson · Accepted solution]

Hi Den:

You need to double quote the extended regular expression so that the shell doesn't interpret the special characters but lets them pass along to 'grep'.

This works (for example):

# TNSSTRING="curly {} stuff"
# [[ $(echo $TNSSTRING | egrep -i "(ORA-01|ORA-27|\{\}|())" | wc -l) -gt 0 ]] && echo OK

...as does this:

# TNSSTRING="this is () NOT a problem"

NOW, you mentioned that your TNSSTRING Variable actually consisted of multiple lines. Filters like 'grep' are not going to help here since they are line-oriented.

With Perl, you could slurp (read-up a whole file into memory) and do things like:

# TNSSTRING="Leo\nthe\ncat"
# echo ${TNSSTRING}
Leo
the
cat

# echo $TNSSTRING | perl -00 -nle 'print "MATCHED" if m{Leo\nthe\ncat}'
MATCHED

LASTLY:

While you ask interesting questions, you sometimes fail to come back to assign points to answers that have been offered. Points are not only a way of saying "thanks!" but bread-crumbs for future trollers to find the tastiest (most applicable) solution:

http://forums.itrc.hp.com/service/forums/helptips.do?#28

Please review your previous posts with unevaluated replies:

http://forums.itrc.hp.com/service/forums/pageList.do?userId=BR967434&listType=unassigned&forumId=1

The time _YOU_ take will be ample reward for the time _WE_ take to help you. Thanks.

Regards!

...JRF...