Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: Regex learning.
Top Forums Shell Programming and Scripting Regex learning. Post 303044737 by RavinderSingh13 on Tuesday 3rd of March 2020 12:09:53 AM
Old 03-03-2020
Hello All,

Learnt an example of Lazy match in Regex in Perl, so thought to share here.
Let's say following is Input_file.

Code:
cat Input_file
abcdtest123^ DUMMYtestabcd12234 DUMMY bla blabla12231311313blabla bla.....,,,,,bla
test132131 ^ DUMMY blabla1213 121313_ 131y7351eg1eub wdfwfknfidh28e7ty;;;

Now we would like to have data between first occurrence of ^ to DUMMY , then we could use Lazy match like as follows:

Code:
perl -pe 's|(\^.*?DUMMY\s+)(.*)| new_text_here.... \2|'  Input_file

Output will be as follows for mentioned sample:
Code:
abcdtest123 new_text_here.... bla blabla12231311313blabla bla.....,,,,,bla
test132131  new_text_here.... blabla1213 121313_ 131y7351eg1eub wdfwfknfidh28e7ty;;;

Why is Lazy match Good here? Because .* is a GREEDY match and matches anything till last occurrence of any mentioned character etc but using Lazy match .*?DUMMY\s+ it matches very first occurrence of string DUMMY followed with space starting from ^

Tested and written this in PERL, thought/views/improvements are most welcome here.

Thanks,
R. Singh
This User Gave Thanks to RavinderSingh13 For This Post:
nezabudka
 

8 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

learning on my own

can i do this? i am learning this on my own..and from the book..simple unix i am not sure if the syntax would work if statement then statement do or for or while statement done else statement fi.... I dont know how else to explain that...I hope I... (2 Replies)
Discussion started by: jonas27
2 Replies

2. Shell Programming and Scripting

Converting perl regex to sed regex

I am having trouble parsing rpm filenames in a shell script.. I found a snippet of perl code that will perform the task but I really don't have time to rewrite the entire script in perl. I cannot for the life of me convert this code into something sed-friendly: if ($rpm =~ /(*)-(*)-(*)\.(.*)/)... (1 Reply)
Discussion started by: suntzu
1 Replies

3. Shell Programming and Scripting

Learning Perl

Folks! Anyone please explain the behavior of this program step by step. Thanks. #! /usr/bin/perl $testfile = "./testfile2"; for ( $i = 1, $i <= 5, $i++) { open ($FILE, ">", $testfile); print ($FILE "Output 1 \n"); close ($FILE); } print "The value of (4 * 2) / 2 is "; print (4 * 2)... (1 Reply)
Discussion started by: huko99
1 Replies

4. UNIX for Dummies Questions & Answers

Need advice on learning RegEx

Hello Unix graduates, I have gone through 50 posts here in this Unix.com, out of which 35-40 are answered with regex.. Regex is always been a problem for me. :wall: I have gone through few URLs still it doesn't help me to reach what you guys are.. :confused: How to get skilled on... (1 Reply)
Discussion started by: sathyaonnuix
1 Replies

5. UNIX for Dummies Questions & Answers

read regex from ID file, print regex and line below from source file

I have a file of protein sequences with headers (my source file). Based on a list of IDs (which are included in some of the headers), I'd like to print out only the specified sequences, with only the ID as header. In other words, I'd like to search source.txt for the terms in IDs.txt, and print... (3 Replies)
Discussion started by: pathunkathunk
3 Replies

6. Programming

Learning C with CBT?

Hello All, I am a beginner in C, although I believe my learning curve is rather steep. I would like to know if any of you would have some recommendations with some learning materials to become a good C developer. I am particularly thinking about some CBT courses or some good Quizz that would... (2 Replies)
Discussion started by: freddie50
2 Replies

7. Shell Programming and Scripting

Perl, RegEx - Help me to understand the regex!

I am not a big expert in regex and have just little understanding of that language. Could you help me to understand the regular Perl expression: ^(?!if\b|else\b|while\b|)(?:+?\s+){1,6}(+\s*)\(*\) *?(?:^*;?+){0,10}\{ ------ This is regex to select functions from a C/C++ source and defined in... (2 Replies)
Discussion started by: alex_5161
2 Replies

8. Shell Programming and Scripting

Sendmail K command regex: adding exclusion/negative lookahead to regex -a@MATCH

I'm trying to get some exclusions into our sendmail regular expression for the K command. The following configuration & regex works: LOCAL_CONFIG # Kcheckaddress regex -a@MATCH +<@+?\.++?\.(us|info|to|br|bid|cn|ru) LOCAL_RULESETS SLocal_check_mail # check address against various regex... (0 Replies)
Discussion started by: RobbieTheK
0 Replies

LEARN ABOUT DEBIAN

lr_deanonymize

LR_DEANONYMIZE.IN(1)					  LogReport's Lire Documentation				      LR_DEANONYMIZE.IN(1)

NAME

       lr_deanonymize - restore anonymized data, using a dump as produced by lr_anonymize(1)

SYNOPSIS

       lr_deanonymize dumpfilestem

DESCRIPTION

       lr_deanonymize is typically used when receiving anonymized reports from a responder.  See the section on "Processing The Responder's
       Results" in the chapter on "Using A Responder" in the Lire User Manual for usage examples.

       lr_deanonymize reads a file containing anonymized emailaddresses, ipnumbers, and hostnames (typically a report, generated from a logfile
       from an internet service) from stdin, and prints a "deanonymized" version of this file to stdout. It reads its information to do this from
       a bunch of Berkeley DB's, stored in files whose's names are derived from dumpfilestem, as produced by lr_anonymize(1).

EXAMPLE

       A 'logfile' like e.g.

	blaat fkrf 1.2.3.4.in-addr.arpa] pietje@bigcompany.com bla 1 2 3 lj;agas;gag
	blaat 1.2.3.4 fkrf 3.2.3.4.in-addr.arpa] bla 1 www.hotsex.com 2 3 lj;agas;gag
	jan@blaat.frut.com agagag
	blaat fkrf 4.2.3.4.in-addr.arpa] bla pietje@bigcompany.com www.hotsex.com
	234.34.2.0 jan@blaat.frut.com 4.2.3.4.in-addr.arpa1 2 3 lj;agas;gag
	blaat fkrf tweede 3.2.3.4.in-addr.arpa] bla 1.2.3.4 1 blablabla.com
	2 mdcc.cx
	3 lj;agas;gag

       wil get anonymized to

	blaat fkrf 1.0.0.10.in-addr.arpa] john.doe.1@example.com bla 1 2 3 lj;agas;gag
	blaat 10.0.0.1 fkrf 2.0.0.10.in-addr.arpa] bla 1 1.example.com 2 3 lj;agas;gag
	john.doe.2@example.com agagag
	blaat fkrf 3.0.0.10.in-addr.arpa] bla john.doe.1@example.com 1.example.com
	10.0.0.2 john.doe.2@example.com 3.0.0.10.in-addr.arpa1 2 3 lj;agas;gag
	blaat fkrf tweede 2.0.0.10.in-addr.arpa] bla 10.0.0.1 1 2.example.com
	2 3.example.com
	3 lj;agas;gag

       The dump will look like

	ip 234.34.2.0 10.0.0.2
	ip 1.2.3.4 10.0.0.1
	inaddr 3.2.3.4.in-addr.arpa 2.0.0.10.in-addr.arpa
	inaddr 1.2.3.4.in-addr.arpa 1.0.0.10.in-addr.arpa
	inaddr 4.2.3.4.in-addr.arpa 3.0.0.10.in-addr.arpa
	domain mdcc.cx 3.example.com
	domain blablabla.com 2.example.com
	domain www.hotsex.com 1.example.com
	email jan@blaat.frut.com john.doe.2@example.com
	email pietje@bigcompany.com john.doe.1@example.com

SEE ALSO

       lr_anonymize(1)

VERSION

       $Id: lr_deanonymize.in,v 1.4 2006/07/23 13:16:32 vanbaal Exp $

COPYRIGHT

       Copyright (C) 2000-2001 Stichting LogReport Foundation LogReport@LogReport.org

       This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by
       the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

       This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

       You should have received a copy of the GNU General Public License along with this program (see COPYING); if not, check with
       http://www.gnu.org/copyleft/gpl.html.

AUTHOR

       Joost van Baal <joostvb@logreport.org>

Lire 2.1.1							    2006-07-23						      LR_DEANONYMIZE.IN(1)
All times are GMT -4. The time now is 10:32 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy