Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: Perl REGEX help
Top Forums Shell Programming and Scripting Perl REGEX help Post 302995100 by timj123 on Friday 31st of March 2017 02:10:21 PM
Old 03-31-2017
Perl REGEX help
Experts -
I found a script on one of the servers that I work on and I need help understanding
one of the lines.

I know what the script does, but I'm having a hard time understanding the grouping.

Can someone help me with this?

Here's the script...
Code:
#!/usr/bin/perl

use strict;
use warnings;

print ipv6_expand($ARGV[0]);

sub ipv6_expand
{
    local($_) = shift;
    chomp($_);
    s/^:/0:/;
    s/:$/:0/;
    s/(^|:)([^:]{1,3})(?=:|$)/$1.substr("0000$2", -4)/ge; # I don't understand this line
    my $temp = tr/:/:/;
    s/::/":".("0000:" x (8-$temp))/e;
    return $_;
}

Thanks in advance!
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

q with Perl Regex

For a programming exercise, I am mean to design a Perl script that detects double letters in a text file. I tried the following expressions # Check for any double letter within the alphabet /+/ # Check for any repetition of an alphanumeric character /\w+/ Im aware that the... (8 Replies)
Discussion started by: JamesGoh
8 Replies

2. Shell Programming and Scripting

Perl REGEX

Hi, Can anyone help me to find regular expression for the following in Perl? "The string can only contain lower case letters (a-z) and no more than one of any letter." For example: "table" is accepted, whether "dude" is not. I have coded like this: $str = "table"; if ($str =~ m/\b()\b/) {... (4 Replies)
Discussion started by: evilfreakz
4 Replies

3. Shell Programming and Scripting

Perl regex

I have got numbers like l255677 l376039 l188144 l340482 l440700 l254113 to match the numbers starting with '13' what would be the regex =~/13(.*)/ =======>This is not working .... But for user123,user657 regex =~/user(.*)/ ========>works Thanks for help..!! (7 Replies)
Discussion started by: trina_1
7 Replies

4. 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

5. UNIX for Dummies Questions & Answers

Perl Regex Help!!!

Hi, I get the following when I cat a file *.log xxxxx ===== dasdas gwdgsg fdsagfsag agsdfag ===== random data ===== My output should look like : If the random data after the 2nd ==== is null then OK should be printed else the random data should be printed. How do I go about this... (5 Replies)
Discussion started by: manutd
5 Replies

6. Programming

Perl regex

HI, I'm new to perl and need simple regex for reading a file using my perl script. The text file reads as - filename=/pot/uio/current/myremificates.txt certificates=/pot/uio/current/userdir/conf/user/gamma/settings/security/... (3 Replies)
Discussion started by: jhamaks
3 Replies

7. Programming

Perl regex

Hi Guys I have the following regex $OSRELEASE = $1 if ($output =~ /(Mac OS X (Server )?10.\d)/); output is currently Mac OS X 10.7.5 when the introduction of Mac 10.8 output changes to OS X 10.8.2 they have dropped the Mac bit so i changed the regex to be (2 Replies)
Discussion started by: ab52
2 Replies

8. Programming

Perl regex

Hello, I'm trying to get a quick help on regex since i'm not a regular programmer. Below is the line i'm trying to apply my regex to..i want to use the regex in a for loop and this line will keep on changing. subject=... (4 Replies)
Discussion started by: jhamaks
4 Replies

9. Shell Programming and Scripting

?= in perl regex

Could anyone please make me understand how the ?= works below .. After executing this I am getting the same output. $string="I love chocolate."; $string =~ s/chocolate(?= ice)/vanilla/; print "$string\n"; (2 Replies)
Discussion started by: scriptscript
2 Replies

10. 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

LEARN ABOUT NETBSD

dh_installdebconf

DH_INSTALLDEBCONF(1)                                                 Debhelper                                                DH_INSTALLDEBCONF(1)

NAME

       dh_installdebconf - install files used by debconf in package build directories

SYNOPSIS

       dh_installdebconf [debhelperoptions] [-n] [--params]

DESCRIPTION

       dh_installdebconf is a debhelper program that is responsible for installing files used by debconf into package build directories.

       It also automatically generates the postrm commands needed to interface with debconf. The commands are added to the maintainer scripts by
       dh_installdeb. See dh_installdeb(1) for an explanation of how that works.

       Note that if you use debconf, your package probably needs to depend on it (it will be added to ${misc:Depends} by this program).

       Note that for your config script to be called by dpkg, your postinst needs to source debconf's confmodule. dh_installdebconf does not
       install this statement into the postinst automatically as it is too hard to do it right.

FILES

       debian/package.config
           This is the debconf config script, and is installed into the DEBIAN directory in the package build directory.

           Inside the script, the token #DEBHELPER# is replaced with shell script snippets generated by other debhelper commands.

       debian/package.templates
           This is the debconf templates file, and is installed into the DEBIAN directory in the package build directory.

       debian/po/
           If this directory is present, this program will automatically use po2debconf(1) to generate merged templates files that include the
           translations from there.

           For this to work, your package should build-depend on po-debconf.

OPTIONS

       -n, --no-scripts
           Do not modify postrm script.

       -- params
           Pass the params to po2debconf.

SEE ALSO

       debhelper(7)

       This program is a part of debhelper.

AUTHOR

       Joey Hess <joeyh@debian.org>

11.1.6ubuntu2                                                       2018-05-10                                                DH_INSTALLDEBCONF(1)
All times are GMT -4. The time now is 03:42 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy