Speaking of style... I took the liberty of rewriting your script.

#!/usr/bin/perl -w
use strict;

my $infile = shift;
my $outfile = "$newfile.tmp";
open my $infh,  '<',  $infile  or die "Cannot open $infile: $!\n";
open my $outfh, '>>', $outfile or die "Cannot open $outfile: $!\n";

while (<$infh>) {
    s/^\s+//g;
    s/\s+$//g;
    print $outfh $_, "\n" or die "Cannot write to $outfile: $!\n";
}

close my $outfh or die "Cannot close $outfile: $!\n";
close my $infh  or die "Cannot close $infile: $!\n";

system('perltidy', $outfile) == 0 or die "Perltidy failed\n";

rename "$outfile.tdy", $infile or die "Cannot rename $outfile.tdy: $!\
+n";
unlink $outfile                or die "Cannot unlink $outfile: $!\n";
chmod 0755, $infile            or die "Cannot chmod $infile: $!\n";
[download]

Changes include:

• use strict
• Got rid of all global variables, including file handles
• Modern three argument open to avoid bugs
• Sane indenting instead of an awful mess
• Parens only where needed instead of ... I guess at random
• Error checking on all system stuff. In the real world, many things can go wrong
• Passing a list of $_ and \n to print instead of a concatenated string, for efficiency
• Renaming of 'newfile'. Why 'new' anyway?

I don't understand:

• why you remove whitespace. perltidy does that for you.
• why you chmod the file using a hardcoded value (use the original permissions!)
• why there is no error message that indicates usage if @ARGV != 1

And you should probably not just filter whitespace like that. The whitespace might be in a string literal!

Juerd
- http://juerd.nl/
- spamcollector_perlmonks@juerd.nl (do not use).