Shell Programming and Scripting

@command = `cat FILE.txt |cut -d "|" -f1 >OUTPUT.txt`;

346566
676875
768674
567567
344556

perl -e '@command = `cat FILE.txt |cut -d "|" -f1`; print map{$_-2 ."\n"}@command' > OUTPUT.txt

open FILE, ">OUTPUT.txt"; 
@command = `cat FILE.txt |cut -d "|" -f1`; 
print FILE map{$_-2 ."\n"}@command;

perl -nle 'split /\|/; print $_[0]-2;' FILE.txt > OUTPUT.txt

open my $in,  '<bla.txt';
open my $out, '>OUTPUT.txt';
print $out map { chomp; split /\|/; $_[0] - 2, "\n" } <$in>;
close $out;
close $in;