This looks to work for me on your sample data:

#!/usr/bin/env perl 
use strict;
use warnings;

my $data = 'unwanted_line1=blabla
unwanted_line2=blabla
my_variable=important_content_section1
important_content_section2
important_content_section3
unwanted_line3=blabla
';

my ($getVariable) = $data =~ /(my_variable=.*)^\w+=/sm;
print $getVariable;

[download]

Update: See Eily's first reply below. If unwanted_line3 is not the last unwanted line in the set after all, then you'll need a non-greedy grab on the capture group like so:

#!/usr/bin/env perl 
use strict;
use warnings;

my $data = 'unwanted_line1=blabla
unwanted_line2=blabla
my_variable=important_content_section1
important_content_section2
important_content_section3
unwanted_line3=blabla
nonsense
unwanted_line4=blabla
whocansay
';

my ($getVariable) = $data =~ /(my_variable=.*?)^\w+=/sm;
print $getVariable;

[download]

In reply to Re: Multiline regex by hippo
in thread Multiline regex by adrya407

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