Here's another way, using grep to exclude lines matching the unwanted pattern as they are read in from the file:

...
use strict;

my $file = 'data_file.txt';
my $bad_pattern = '019';

open my $in_fh, "<$file" or die "can't open $file to read";
my @good_lines = grep { !/$bad_pattern/ } <$in_fh>;
close $in_fh;

open my $out_fh, ">$file" or die "can't open $file to write";
print $out_fh $_ foreach @good_lines;
close $out_fh;
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