Just capture the match! You can get rid if the zero-width assertion at the same time:

my $file = '/etc/redhat-release';

# content of /etc/redhat-release
# CentOS Linux release 7.6.1810 (Core)

open(SOURCE, '<', $file);
my ($version) = <SOURCE> =~ m/release (\d)/;
close SOURCE;

print "The version is: $version\n";

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In reply to Re: Read text in file and assign to variable by haj
in thread Read text in file and assign to variable by maxamillionk

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