ch04.048_best

来自「Perl Best Practices the source code」· 048_BEST 代码 · 共 38 行

##############################################################################
##   Code fragment (Recommended) from Chapter 4 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;

my $usage_error    = 1;
my $requested_file = 'coff';

sub build_usage {
    my ($prog_name, $file_name) = @_;
 
    return <<"END_USAGE";
Usage: $prog_name $file_name [-full] [-o] [-beans]
Options:
    -full  : produce a full dump
    -o     : dump in octal
    -beans : source is Java
END_USAGE
}
 
# and later...
 
if ($usage_error) {
    warn build_usage($PROGRAM_NAME, $requested_file);
}