trim-whitespace

#!/usr/bin/perl

use strict;
use warnings;

use Getopt::Long;

Getopt::Long::Configure('bundling');

my %opts = ( verbosity => 1 );
GetOptions(
  \%opts,
  'help|h',
  'leading|l', 'trailing|t',
) or usage();
usage() if $opts{help};

sub usage {
  warn @_, "\n" if @_;

  (my $ME = $0) =~ s,.*/,,;

  die <<EOUSAGE;
Usage: $ME [options]
Trims leading/trailing whitespace from each line.

Options:
  -l, --leading        Only trim leading whitespace
  -t, --trailing       Only trim trailing whitespace
  -h, --help           Show this help
EOUSAGE
}

if (! $opts{leading} && ! $opts{trailing}) {
  # Default to trimming both if no options specified.
  $opts{leading} = $opts{trailing} = 1;
}

my $to_trim = qr/[ \t]+/;

while (<>) {
  s/^$to_trim// if $opts{leading};
  s/$to_trim$// if $opts{trailing};
  print;
}