1App::Cmd::Simple(3)   User Contributed Perl Documentation  App::Cmd::Simple(3)
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NAME

6       App::Cmd::Simple - a helper for building one-command App::Cmd
7       applications
8

VERSION

10       version 0.331
11

SYNOPSIS

13       in simplecmd:
14
15         use YourApp::Cmd;
16         Your::Cmd->run;
17
18       in YourApp/Cmd.pm:
19
20         package YourApp::Cmd;
21         use base qw(App::Cmd::Simple);
22
23         sub opt_spec {
24           return (
25             [ "blortex|X",  "use the blortex algorithm" ],
26             [ "recheck|r",  "recheck all results"       ],
27           );
28         }
29
30         sub validate_args {
31           my ($self, $opt, $args) = @_;
32
33           # no args allowed but options!
34           $self->usage_error("No args allowed") if @$args;
35         }
36
37         sub execute {
38           my ($self, $opt, $args) = @_;
39
40           my $result = $opt->{blortex} ? blortex() : blort();
41
42           recheck($result) if $opt->{recheck};
43
44           print $result;
45         }
46
47       and, finally, at the command line:
48
49         knight!rjbs$ simplecmd --recheck
50
51         All blorts successful.
52

SUBCLASSING

54       When writing a subclass of App::Cmd:Simple, there are only a few
55       methods that you might want to implement.  They behave just like the
56       same-named methods in App::Cmd.
57
58   opt_spec
59       This method should be overridden to provide option specifications.
60       (This is list of arguments passed to "describe_options" from
61       Getopt::Long::Descriptive, after the first.)
62
63       If not overridden, it returns an empty list.
64
65   usage_desc
66       This method should be overridden to provide the top level usage line.
67       It's a one-line summary of how the command is to be invoked, and should
68       be given in the format used for the $usage_desc parameter to
69       "describe_options" in Getopt::Long::Descriptive.
70
71       If not overriden, it returns something that prints out like:
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73         yourapp [-?h] [long options...]
74
75   validate_args
76         $cmd->validate_args(\%opt, \@args);
77
78       This method is passed a hashref of command line options (as processed
79       by Getopt::Long::Descriptive) and an arrayref of leftover arguments.
80       It may throw an exception (preferably by calling "usage_error") if they
81       are invalid, or it may do nothing to allow processing to continue.
82
83   execute
84         Your::App::Cmd::Simple->execute(\%opt, \@args);
85
86       This method does whatever it is the command should do!  It is passed a
87       hash reference of the parsed command-line options and an array
88       reference of left over arguments.
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WARNINGS

91       This should be considered experimental!  Although it is probably not
92       going to change much, don't build your business model around it yet,
93       okay?
94
95       App::Cmd::Simple is not rich in black magic, but it does do some
96       somewhat gnarly things to make an App::Cmd::Simple look as much like an
97       App::Cmd::Command as possible.  This means that you can't deviate too
98       much from the sort of thing shown in the synopsis as you might like.
99       If you're doing something other than writing a fairly simple command,
100       and you want to screw around with the App::Cmd-iness of your program,
101       Simple might not be the best choice.
102
103       One specific warning...  if you are writing a program with the
104       App::Cmd::Simple class embedded in it, you must call import on the
105       class.  That's how things work.  You can just do this:
106
107         YourApp::Cmd->import->run;
108

AUTHOR

110       Ricardo Signes <rjbs@cpan.org>
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113       This software is copyright (c) 2016 by Ricardo Signes.
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115       This is free software; you can redistribute it and/or modify it under
116       the same terms as the Perl 5 programming language system itself.
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120perl v5.32.0                      2020-07-28               App::Cmd::Simple(3)
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