#!/usr/bin/env perl -l

use strict;
use warnings;

my $string = "\t is a TAB\n is a SPACE\nTAB\t and SPACE";

print '*** BEFORE ***';
print $string;

$string =~ s/(?<!$)\s//gm;

print '*** AFTER ***';
print $string;

##</code><code>##

*** BEFORE ***
	 is a TAB
 is a SPACE
TAB	 and SPACE
*** AFTER ***
isaTAB
isaSPACE
TABandSPACE

##</code><code>##

#!/usr/bin/env perl -l

use strict;
use warnings;

my $string = "\t is a TAB\n is a SPACE\nTAB\t and SPACE";

print '*** BEFORE ***';
print $string;

$string =~ y/\t //d;

print '*** AFTER ***';
print $string;

##</code><code>##

*** BEFORE ***
	 is a TAB
 is a SPACE
TAB	 and SPACE
*** AFTER ***
isaTAB
isaSPACE
TABandSPACE