ch10.064_prob

Perl Best Practices the source code

##############################################################################
## Code fragment (NOT RECOMMENDED) from Chapter 10 of "Perl Best Practices" ##
##     Copyright (c) O'Reilly & Associates, 2005. All Rights Reserved.      ##
##  See: http://www.oreilly.com/pub/a/oreilly/ask_tim/2001/codepolicy.html  ##
##############################################################################


# Standard modules...
use strict;
use warnings;
use IO::Prompt;
use Carp;
use English qw( -no_match_vars );
use Data::Alias;
use Readonly;

use IO::Interactive qw( is_interactive );
Readonly my $EMPTY_STR => q{};
Readonly my $QUIT => qr/\A q(?:uit)? \z/ixms;

my $count = 0;
sub get_prompt_str {
    $count++;
    return "$count> ";
}

sub execute {
    my ($cmd) = @_;
    print "executing: $cmd\n";
}

# No command entered yet...
my $cmd = $EMPTY_STR;
 
# Until the q[uit] command is entered...
CMD:
while ($cmd !~ $QUIT) {
    # Prompt if we're running interactively...
    if (is_interactive()) {
        print get_prompt_str();
    }
 
    # Get the next command...
    $cmd = <>;
    last CMD if not defined $cmd;
 
    # Clean it up and run it...
    chomp $cmd;
    execute($cmd) 
        or carp "Unknown command: $cmd";
}