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

my @strings = qw(string justification 999999999 88888888 7777777);

sub justify{
    my ($string,
        $len,
        $char,
        $pad_from,
        $strict) = @_;

    return '' unless defined $string;
    $pad_from ||= '';
    $pad_from =~ tr{a-z}{A-Z};
    $pad_from = '' unless $pad_from =~ s{^([LCR]).*?$}{$1};

    if($string =~ m{\D}){
        $pad_from ||= 'L';
        defined($char ) or $char = ' ';
    }else{
        $pad_from ||= 'R';
        defined($char ) or $char = '0';
    }

    $len ||= 10;
    
    my $tmpstr = '';
    my $offset = 0;
    
    if    ($pad_from eq 'R'){
        $tmpstr = $char x ($len - length $string).$string;
    }elsif($pad_from eq 'C'){
        $strict = 1;
        my $pad = $char x (int(($len - length $string) / 2));
        $tmpstr = $pad.$string.$pad.$char;
    }elsif($pad_from eq 'L'){
        $tmpstr = $string.($char x ($len - length $string));
    }
    
    unless ($strict){
        $len = length( $tmpstr )> $len ? length $tmpstr : $len;
    }
    return (substr($tmpstr,$offset,$len));
    
}


# EXAMPLES
sub maxsize{
   my $maxsize       = 0;
   my $to_measure    = shift;
   for (@$to_measure){
      my $thissize   = length;
      $maxsize       = $thissize unless $maxsize > $thissize; 
   }
   $maxsize ;
}

my %example = (#pad to default do not truncate
                 default => q{justify($_)},
                #pad to 9, truncate
                 nine    => q{justify($_,9,undef,undef,1)},
                #right justify in 9 cols, default pad, truncate
                 right_  => q{justify($_,9,undef,'R',1)},
                #left justify in 9 cols, default pad, truncate
                 left_   => q{justify($_,9,undef,'L',1)},
                #pad ' ' to max len, center 
                 center  => q{justify($_,maxsize(\@strings),' ','c')},
                #pad '-' to max len default justify
                 fill    => q{justify($_,maxsize(\@strings),'-')}
                );
                
my $padex = maxsize([keys %example]);
for my $ex (sort keys %example){
    print justify($ex,$padex,undef,'l',1)." : ".eval($example{$ex})."\
+n" for @strings;
    print "\n";
}

__END__
center  :    string    
center  : justification
center  :   999999999  
center  :   88888888   
center  :    7777777   

default : string    
default : justification
default : 0999999999
default : 0088888888
default : 0007777777

fill    : string-------
fill    : justification
fill    : ----999999999
fill    : -----88888888
fill    : ------7777777

left_   : string   
left_   : justifica
left_   : 999999999
left_   : 888888880
left_   : 777777700

nine    : string   
nine    : justifica
nine    : 999999999
nine    : 088888888
nine    : 007777777

right_  :    string
right_  : justifica
right_  : 999999999
right_  : 088888888
right_  : 007777777
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