Shell Programming and Scripting

Hi folks,

I have a line in log from which I need to parse few data.

Code:

Jul  6 00:05:58 dg01aipagnfe01p %FWSM-3-106011: Deny inbound (No xlate)

From the above... I need to parse the %FWSM-3-106011: substring.

Another example

Code:

Jul 13 00:08:55 dq01aipaynas01p %FWSM-6-302010: 2 in use, 1661 most used

from the above Ineed to parse the %FWSM-6-302010: substring in perl.

Could anyone please let me know how to parse as mentioned above in PERL..


Thanks in advance ....

Regards,
J

Please post the attempts you've made so far to solve this problem.

Hi durden_tyler,

Code:

$line = "Jul 13 00:08:55 dq01aipaynas01p %FWSM-6-302010: 2 in use, 1661: most used";

$line =~ m/(\%(.*)\:)/;

print "\n matched";
print $&;

## printing %FWSM-6-302010: 2 in use, 1661:  but expected is %FWSM-6-302010:

Could you please help me ???

A few thoughts on your regex:

(1)

Code:

.*

is a "greedy quantifier". It will match as much of the string as possible while still allowing the entire regex to match the string.

So the match starts from the "%" character and it matches as many characters as possible to reach the next ":" character. That is the reason the match goes beyond the first ":" character, and goes on till the second (and last) ":" character.

What you are looking for is a "non-greedy quantifier", which is formed by the usual quantifier appended by a "?". That will match as few characters as possible and stop at the first ":" after the "%" character.

Search for "non-greedy quantifier" in the official Perl regex tutorial : perlretut - perldoc.perl.org for a detailed review of this concept.

(2)
You don't need any of the braces

Code:

( )

unless you want to store the matched string in special variable

Code:

$1

and the part of the string between "%" and ":" in special variable

Code:

$2

(3)
"%" and ":" are not special characters, so you don't have to escape them. To see a legitimate list of special characters, search for "metacharacters" in the Perl regex tutorial: perlretut - perldoc.perl.org