Solved

Removing a line from a file.

Posted on 2007-11-23
4
190 Views
Last Modified: 2012-05-05
I know this question is everywhere on here - but im missing some detail, either due to brain fart or...  I figured this out a few weeks ago and either deleted it or forgot to document it now i can't seem to figure it out again. Argg - thanks for your help!

Heres the one liner:
perl -i -ne 'print unless /EXP/' file

This prints contents minus the line in the match.

My needs:
1. Needs to be in perl script not a one liner.
2. Needs to remove the line from a file permanently
3. There are 3 columns in the file, we only know the content of one portion of the line.

Example data from dbfile.txt:
12121:someuser_1:domain_1.com
12122:someuser_2:domain_2.com
12123:someuser_3:domain_3.com
12124:someuser_4:domain_4.com
12125:someuser_5:domain_5.com
12126:someuser_6:domain_6.com
12127:someuser_7:domain_7.com
12128:someuser_8:domain_8.com
12129:someuser_9:domain_9.com

The only information we have is domain_5.com so we need to remove that entire line containing that domain.

0
Comment
Question by:kipper3d
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
4 Comments
 
LVL 17

Expert Comment

by:mjcoyne
ID: 20340653
#!/usr/bin/perl -w
use strict;

open (IN, ">dbfile.txt") or die "Couldn't open dbfile.txt: $!\n";
open (OUT, ">dbfile-new.txt") or die "Couldn't open dbfile-new.txt: $!\n";

while (<IN>) {
    print OUT unless (/:domain_5\./);
}
0
 
LVL 17

Accepted Solution

by:
mjcoyne earned 50 total points
ID: 20340655
Sorry --  DO NOT use that script.  It'll clobber your dbfile.txt original.  Here's the corrected version:

#!/usr/bin/perl -w
use strict;

open (IN, "dbfile.txt") or die "Couldn't open dbfile.txt: $!\n";
open (OUT, ">dbfile-new.txt") or die "Couldn't open dbfile-new.txt: $!\n";

while (<IN>) {
    print OUT unless (/:domain_5\./);
}
0
 
LVL 1

Author Closing Comment

by:kipper3d
ID: 31410710
Thanks mjcoyne,

This wasn't what i had before but it works - so thanks!
0
 
LVL 84

Expert Comment

by:ozo
ID: 20340875
#!/usr/bin/perl
local $^I=".bak";
local @ARGV=("dbfile.txt");
while( <> ){
   print unless /:domain_5\./;
}
0

Featured Post

Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

There are many situations when we need to display the data in sorted order. For example: Student details by name or by rank or by total marks etc. If you are working on data driven based projects then you will use sorting techniques very frequently.…
Checking the Alert Log in AWS RDS Oracle can be a pain through their user interface.  I made a script to download the Alert Log, look for errors, and email me the trace files.  In this article I'll describe what I did and share my script.
Explain concepts important to validation of email addresses with regular expressions. Applies to most languages/tools that uses regular expressions. Consider email address RFCs: Look at HTML5 form input element (with type=email) regex pattern: T…

737 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question