Simple Perl script for formatting code for posting

by Isaac Marino Bavaresco

This script formats program listings for posting in the site.

It takes two arguments, the name of the file and optionally a number for TAB size. If the TAB size is ommited, it is assumed to be 8.

The script replaces all TABs by a number of spaces sufficient for the next character begin in a column multiple of the TAB size plus 1. It replaces also all "&" by "&amp;" and all "<" by "&lt;".

#!/usr/bin/perl
#===============================================================================
# Copyright (c) 2009, Isaac Marino Bavaresco
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#     * Redistributions of source code must retain the above copyright
#       notice, this list of conditions and the following disclaimer.
#     * Neither the name of the author nor the
#       names of its contributors may be used to endorse or promote products
#       derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ''AS IS'' AND ANY
# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#===============================================================================
# isaacbavaresco@yahoo.com.br
#===============================================================================
use strict;
use warnings;
#-------------------------------------------------------------------------------
die "Invalid number of arguments" if( $#ARGV + 1 < 1 || $#ARGV + 1 > 2 );

my $FileName    = $ARGV[0];
my $TabSize     = 8;
if( $#ARGV + 1 == 2 )
    {
    $TabSize    = $ARGV[1];
    }

open( my $Handle, $FileName ) or die "It was not possible to open the file!";

while( my $Line = <$Handle> )
    {
    ( $Line ) = $Line =~ /(.*[^\s])\s*$/;
    if( !$Line )
        {
        $Line   = "";
        }

    for( my $Column = 1, my $Index  = 0; ( my $c = substr( $Line, $Index, 1 )) ne ""; $Index++ )
        {
        if( $c eq "\t" )
            {
            my $NextTab = $TabSize - (( $Column - 1 ) % $TabSize );
            $Column += $NextTab;
            for( ; $NextTab; $NextTab-- )
                {
                printf( " " );
                }
            }
        elsif( $c eq "&" )
            {
            printf( "&amp;" );
            $Column++;
            }
        elsif( $c eq "<" )
            {
            printf( "&lt;" );
            $Column++;
            }
        else
            {
            printf( "%s", $c );
            $Column++;
            }
        }
    printf( "\n" );
    }

close( $Handle );
#===============================================================================