Perl Guru Forums: Perl Programming Help: Regular Expressions: Search and replace help : Perl one liner

CGI/Perl Guide | Learning Center | Forums | Advertise | Login

Site Search: in


	MAIN INDEX	SEARCH POSTS	WHO'S ONLINE	LOG IN

Home: Perl Programming Help: Regular Expressions:
Search and replace help : Perl one liner

jaggims
New User

Dec 7, 2012, 7:55 AM

Post #1 of 5 (3971 views)

Search and replace help : Perl one liner	Can't Post

hi i am trying to use perl oe liner to search old cell names and replace with new cell names in many category files, but some how it doesnt work, could be there is a special character in between.

see the below example

category.file

esd_gold/cellName1 type="cell"
esd_gold/cellName2 type="cell"
esd_gold/cellName3 type="cell"
esd_gold/cellName4 type="cell"
esd_gold/cellName5 type="cell"
esd_gold/cellName5_temp type="cell"

i am interested to replace only cellName* with new cell names (say cellnameA cellNameB cellNameC cellNameD & cellNameE, for this i am using below onle liner but it doesnt work when the part of a cell name repeats multiple times it goes wrong.

perl -p -i -e 's/$existing_string/$replacing_string/g' category.file

Laurent_R
Enthusiast / Moderator

Dec 7, 2012, 10:12 AM

Post #2 of 5 (3961 views)

Re: [jaggims] Search and replace help : Perl one liner [In reply to]	Can't Post

In Reply To

perl -p -i -e 's/$existing_string/$replacing_string/g' category.file

If you use this one-liner, this cannot work, since the $existing_string and $replacing_string variables have not been defined anywhere in the script, so that the script does know what you want to match and by what you want the matched pattern to be replaced.

Actually, I don't know either what you want to replace by what. You don't give enough information for us to help you.

If you said something like "I want to replace 'cellName5' by 'Cell_name5'", I would immediately know what to suggest. But, here, we don't really know.

BillKSmith
Veteran

Dec 7, 2012, 12:58 PM

Post #3 of 5 (3956 views)

Re: [jaggims] Search and replace help : Perl one liner [In reply to]	Can't Post

This probably is not sufficiently general, but it does what you ask for;

Code

use strict; 
use warnings; 
my @suffixes = qw( _ A B C D E); 
while (<>) { 
    s/(cellName)(\d)/$1$suffixes[$2]/; 
    print; 
}

Good Luck,
Bill

jaggims
New User

Dec 10, 2012, 4:56 AM

Post #4 of 5 (3877 views)

Re: [Laurent_R] Search and replace help : Perl one liner [In reply to]	Can't Post

Hi,

basically i want to find a reg-exp to search and replace a whole word, i use below option, but it doesnt work
system("/usr/local/bin/perl -p -i -e 's/\b$existing_string\b/\b$replacing_string\b/g' /remote/de02h26/jmuddaia/tmp_esd_gold/USB_unique.Cat_copy");

Laurent_R
Enthusiast / Moderator

Dec 10, 2012, 10:41 AM

Post #5 of 5 (3867 views)

Re: [jaggims] Search and replace help : Perl one liner [In reply to]	Can't Post

If I understand you well, you're trying to launch a Perl one-line script from a Perl program, using the system function.

Why, for god's sake, would you want to to that? You can do directly in your Perl program everything that you want to do in the one-liner. Unless your favorite motto is: "why should we do things simple when they can be made complicated?"...

Just read the file in tour perl program and do the changes you need.

Search for (options)

Web Applications & Managed Hosting Powered by Gossamer Threads
Visit our Mailing List Archives