#!/usr/bin/perl -w
=head1 NAME

randomize [-v] file... > random_file

=head1 SYNOPSIS

  randomize [-v] file... > random_file
  Options:  -v    Output lines to error channel too
            -#    Limit the number of lines to output

=head1 DESCRIPTION

Simple perl program to completely randomize the order of the
lines of all the files given.

=head1 AUTHOR

  Anthony Thyssen

=cut
sub Usage {
  use Pod::Usage;
  pod2usage("@_");
  exit 10;
}

my $lines = 0;  # output all the lines in the file
my $verbose = 0;

ARGUMENT:  # Multi-switch option handling
while( @ARGV && $ARGV[0] =~ s/^-(?=.)// ) {
  $_ = shift; {
    m/^$/  && do { next };     # next argument
    m/^-$/ && do { last };     # End of options
    m/^\?/ && do { Usage };    # Usage Help

    s/^(\d+)// && do { $lines = $1;  redo }; # number of lines
    s/^v//     && do { $verbose++;   redo }; # output to stderr too

    Usage( "Unknown Option \"-$_\"\n" );
  } continue { next ARGUMENT }; last ARGUMENT;
}

# ----------------------------------------
srand($$^time);

@lines = <>;    # read in all lines in files given

while( $#lines >= 0 ) {
  $line = splice(@lines, rand(@lines)+$[, 1);
  print $line;
  print STDERR $line   if $verbose;
  last if --$lines == 0;
}