1App::Cmd::Simple(3) User Contributed Perl Documentation App::Cmd::Simple(3)
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6 App::Cmd::Simple - a helper for building one-command App::Cmd
7 applications
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10 version 0.335
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13 in simplecmd:
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15 use YourApp::Cmd;
16 Your::Cmd->run;
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18 in YourApp/Cmd.pm:
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20 package YourApp::Cmd;
21 use parent qw(App::Cmd::Simple);
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23 sub opt_spec {
24 return (
25 [ "blortex|X", "use the blortex algorithm" ],
26 [ "recheck|r", "recheck all results" ],
27 );
28 }
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30 sub validate_args {
31 my ($self, $opt, $args) = @_;
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33 # no args allowed but options!
34 $self->usage_error("No args allowed") if @$args;
35 }
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37 sub execute {
38 my ($self, $opt, $args) = @_;
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40 my $result = $opt->{blortex} ? blortex() : blort();
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42 recheck($result) if $opt->{recheck};
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44 print $result;
45 }
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47 and, finally, at the command line:
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49 knight!rjbs$ simplecmd --recheck
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51 All blorts successful.
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54 This library should run on perls released even a long time ago. It
55 should work on any version of perl released in the last five years.
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57 Although it may work on older versions of perl, no guarantee is made
58 that the minimum required version will not be increased. The version
59 may be increased for any reason, and there is no promise that patches
60 will be accepted to lower the minimum required perl.
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63 When writing a subclass of App::Cmd:Simple, there are only a few
64 methods that you might want to implement. They behave just like the
65 same-named methods in App::Cmd.
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67 opt_spec
68 This method should be overridden to provide option specifications.
69 (This is list of arguments passed to "describe_options" from
70 Getopt::Long::Descriptive, after the first.)
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72 If not overridden, it returns an empty list.
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74 usage_desc
75 This method should be overridden to provide the top level usage line.
76 It's a one-line summary of how the command is to be invoked, and should
77 be given in the format used for the $usage_desc parameter to
78 "describe_options" in Getopt::Long::Descriptive.
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80 If not overridden, it returns something that prints out like:
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82 yourapp [-?h] [long options...]
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84 validate_args
85 $cmd->validate_args(\%opt, \@args);
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87 This method is passed a hashref of command line options (as processed
88 by Getopt::Long::Descriptive) and an arrayref of leftover arguments.
89 It may throw an exception (preferably by calling "usage_error") if they
90 are invalid, or it may do nothing to allow processing to continue.
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92 execute
93 Your::App::Cmd::Simple->execute(\%opt, \@args);
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95 This method does whatever it is the command should do! It is passed a
96 hash reference of the parsed command-line options and an array
97 reference of left over arguments.
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100 This should be considered experimental! Although it is probably not
101 going to change much, don't build your business model around it yet,
102 okay?
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104 App::Cmd::Simple is not rich in black magic, but it does do some
105 somewhat gnarly things to make an App::Cmd::Simple look as much like an
106 App::Cmd::Command as possible. This means that you can't deviate too
107 much from the sort of thing shown in the synopsis as you might like.
108 If you're doing something other than writing a fairly simple command,
109 and you want to screw around with the App::Cmd-iness of your program,
110 Simple might not be the best choice.
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112 One specific warning... if you are writing a program with the
113 App::Cmd::Simple class embedded in it, you must call import on the
114 class. That's how things work. You can just do this:
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116 YourApp::Cmd->import->run;
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119 Ricardo Signes <cpan@semiotic.systems>
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122 This software is copyright (c) 2022 by Ricardo Signes.
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124 This is free software; you can redistribute it and/or modify it under
125 the same terms as the Perl 5 programming language system itself.
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129perl v5.36.0 2023-01-19 App::Cmd::Simple(3)