Shell Programming and Scripting

Thanks a lot Tyler.. Appreciate your qucik reply ... as i have zero knowledge on Perl... hence i would like to understand how actually how the script is working.. Thanks again..

In the simplest terms, the script searches for a line that matches the regular expression pattern and prints a chunk from the pattern.

If you have zero knowledge of Perl, then you are lucky as nowadays there's a huge wealth of resources on the Internet and books etc. that can help you. Google is your friend here. Books by O'Reilly are pretty good.

I can tell you what that regex does, but it would be better if you have at least a rudimentary knowledge of terms like "metacharacters", "backreferences", "character-classes", "repetition quantifiers" before that. You may want to check out the book by Jeffrey Friedl, which is probably one of the best on regexes.

HTH,
tyler_durden

Thanks Tyler...

Assume i have the input file as below

Code:

SEL elapsedtime ,StartTime,QueryText
FROM     dbc.qrylog
WHERE    StartTime >= '2010-03-24 20:10:08'
        AND      username in ('tst1','xxx_yyy_drv_01')

Now i need the ouptut as in , can this be done using perl ... apprceiate help over here

Yes, it can be done using Perl -

Code:

$
$
$ cat file6.sql
SELECT elapsedtime ,StartTime,QueryText
FROM     dbc.qrylog
WHERE    StartTime >= '2010-03-24 20:10:08'
        AND      username in ('tst1','xxx_yyy_drv_01')
$
$
$ perl -lne '/^(\s*\w+){2}\s*(=|in)[\s(]*.*$/ && print $2' file6.sql
in
$
$

tyler_durden

Originally Posted by nitinrp1
...
Assume i have the input file as below



Code:
SEL elapsedtime ,StartTime,QueryText
FROM dbc.qrylog
WHERE StartTime >= '2010-03-24 20:10:08'
AND username in ('tst1','xxx_yyy_drv_01')
and user = ('abc_aaa')

For the above code if i run the perl script given by its gives out put as in and =

the requried output should be only in

thanks again..
pls help

It returns output "in" because "in" is present in the query. Check that last but one line of your query.

It returns output "=" because "=" is present in the query. Check the last line of your query.

(a) Why should it be "in" ?
(b) Why should it not be "=" ?

tyler_durden