1App::Rad(3)           User Contributed Perl Documentation          App::Rad(3)
2
3
4

NAME

6       App::Rad - Rapid (and easy!) creation of command line applications
7

VERSION

9       Version 1.04
10

SYNOPSIS

12       This is your smallest working application (let's call it myapp.pl)
13
14           use App::Rad;
15           App::Rad->run();
16
17       That's it, your program already works and you can use it directly via
18       the command line (try it!)
19
20           [user@host]$ ./myapp.pl
21           Usage: myapp.pl command [arguments]
22
23           Available Commands:
24               help    show syntax and available commands
25
26       Next, start creating your own functions (e.g.) inside myapp.pl:
27
28           sub hello {
29               return "Hello, World!";
30           }
31
32       And now your simple command line program myapp.pl has a 'hello'
33       command!
34
35           [user@host]$ ./myapp.pl
36           Usage: myapp.pl command [arguments]
37
38           Available Commands:
39               hello
40               help    show syntax and available commands
41
42
43          [user@host]$ ./myapp.pl hello
44          Hello, World!
45
46       You could easily add a customized help message for your command through
47       the 'Help()' attribute:
48
49           sub hello
50           :Help(give a nice compliment)
51           {
52               return "Hello, World!";
53           }
54
55       And then, as expected:
56
57           [user@host]$ ./myapp.pl
58           Usage: myapp.pl command [arguments]
59
60           Available Commands:
61               hello   give a nice compliment
62               help    show syntax and available commands
63
64       App::Rad also lets you expand your applications, providing a lot of
65       flexibility for every command, with embedded help, argument and options
66       parsing, configuration file, default behavior, and much more:
67
68           use App::Rad;
69           App::Rad->run();
70
71           sub setup {
72               my $c = shift;
73
74               $c->register_commands( {
75                       foo => 'expand your foo!',
76                       bar => 'have a drink! arguments: --drink=DRINK',
77                   });
78           }
79
80           sub foo {
81               my $c = shift;
82               $c->load_config('myapp.conf');
83
84               return 'foo expanded to ' . baz() * $c->config->{'myfoo'};
85           }
86
87           # note that 'baz' was not registered as a command,
88           # so it can't be called from the outside.
89           sub baz { rand(10) }
90
91           sub bar {
92               my $c = shift;
93               if ( $c->options->{'drink'} ) {
94                   return 'you asked for a ' . $c->options->{'drink'};
95               }
96               else {
97                   return 'you need to ask for a drink';
98               }
99           }
100
101       You can try on the command line:
102
103          [user@host]$ ./myapp.pl
104           Usage: myapp.pl command [arguments]
105
106           Available Commands:
107               bar     have a drink! arguments: --drink=DRINK
108               foo     expand your foo!
109               help    show syntax and available commands
110
111
112          [user@host]$ ./myapp.pl bar --drink=martini
113           you asked for a martini
114

WARNING

116       This module is very young, likely to change in strange ways and to have
117       some bugs (please report if you find any!). I will try to keep the API
118       stable, but even that is subject to change (let me know if you find
119       anything annoying or have a wishlist). You have been warned!
120

DESCRIPTION

122       App::Rad aims to be a simple yet powerful framework for developing your
123       command-line applications. It can easily transform your Perl one-liners
124       into reusable subroutines than can be called directly by the user of
125       your program.
126
127       It also tries to provide a handy interface for your common command-line
128       tasks. If you have a feature request to easen out your tasks even more,
129       please drop me an email or a RT feature request.
130
131   Extending App::Rad - Plugins!
132       App::Rad plugins can be loaded by naming them as arguments to the "use
133       App::Rad" statement. Just ommit the "App::Rad::Plugin" prefix from the
134       plugin name. For example:
135
136          use App::Rad  qw(My::Module);
137
138       will load the "App::Rad::Plugin::My::Module" plugin for you!
139
140       Developers are strongly encouraged to publish their App::Rad plugins
141       under the "App::Rad::Plugin" namespace. But, if your plugin start with
142       a name other than that, you can fully qualify the name by using an
143       unary plus sign:
144
145         use App::Rad  qw(
146                 My::Module
147                 +Fully::Qualified::Plugin::Name
148         );
149
150       Note that plugins are loaded in the order in which they appear.
151
152       Please refer to the actual plugin documentation for specific usage. And
153       check out App::Rad::Plugin if you want to create your own plugins.
154

INSTANTIATION

156       These are the main execution calls for the application. In your
157       App::Rad programs, the *ONLY* thing your script needs to actually (and
158       actively) call is one of the instantiation (or dispatcher) methods.
159       Leave all the rest to your subs. Currently, the only available
160       dispatcher is run():
161
162   run()
163       You'll be able to access all of your program's commands directly
164       through the command line, as shown in the synopsis.
165

BUILT-IN COMMANDS

167       This module comes with the following default commands. You are free to
168       override them as you see fit.
169
170   help
171       Shows help information for your program. This built-in function
172       displays the program name and all available commands (including the
173       ones you added yourself) if a user types the 'help' command, or no
174       command at all, or any command that does not exist (as they'd fall into
175       the 'default' control function which (by default) calls 'help').
176
177       You can also display specific embedded help for your commands, either
178       explicitly registering them with "$c->register()" or
179       "$c->register_commands()" inside "$c->setup()" (see respective sections
180       below) or with the Help() attribute:
181
182           use App::Rad;
183           App::Rad->run();
184
185           sub mycmd
186           :Help(display a nice welcome message)
187           {
188               return "Welcome!";
189           }
190
191       the associated help text would go like this:
192
193           [user@host]$ ./myapp.pl
194           Usage: myapp.pl command [arguments]
195
196           Available Commands:
197               help    show syntax and available commands
198               mycmd   display a nice welcome message
199

OTHER BUILT IN COMMANDS (OPT-IN)

201       The 'include' and 'exclude' commands below let the user include and
202       exclude commands to your program and, as this might be dangerous when
203       the user is not yourself, you have to opt-in on them:
204
205          use App::Rad qw(include);  # add the 'include' command
206          use App::Rad qw(exclude);  # add the 'exclude' command
207
208       though you'll probably want to set them both:
209
210          use App::Rad qw(include exclude);
211
212   include [command_name] -perl_params 'your subroutine code'
213       Includes the given subroutine into your program on-the-fly, just as you
214       would writing it directly into your program.
215
216       Let's say you have your simple 'myapp.pl' program that uses App::Rad
217       sitting on your system quietly. One day, perhaps during your sysadmin's
218       tasks, you create a really amazing one-liner to solve a really hairy
219       problem, and want to keep it for posterity (reusability is always a
220       good thing!).
221
222       For instance, to change a CSV file in place, adding a column on
223       position #2 containing the line number, you might do something like
224       this (this is merely illustrative, it's not actually the best way to do
225       it):
226
227           $ perl -i -paF, -le 'splice @F,1,0,$.; $_=join ",",@F' somesheet.csv
228
229       And you just found out that you might use this other times. What do you
230       do? App::Rad to the rescue!
231
232       In the one-liner above, just switch 'perl' to 'myapp.pl include
233       SUBNAME' and remove the trailing parameters (somesheet.csv):
234
235           $ myapp.pl include addcsvcol -i -paF, -le 'splice @F,1,0,$.; $_=join ",",@F'
236
237       That's it! Now myapp.pl has the 'addcsvcol' command (granted, not the
238       best name) and you can call it directly whenever you want:
239
240           $ myapp.pl addcsvcol somesheet.csv
241
242       App::Rad not only transforms and adjusts your one-liner so it can be
243       used inside your program, but also automatically formats it with
244       Perl::Tidy (if you have it). This is what the one-liner above would
245       look like inside your program:
246
247           sub addcsvcol {
248               my $c = shift;
249
250               local ($^I) = "";
251               local ($/)  = "\n";
252               local ($\)  = "\n";
253             LINE: while ( defined( $_ = <ARGV> ) ) {
254                   chomp $_;
255                   our (@F) = split( /,/, $_, 0 );
256                   splice @F, 1, 0, $.;
257                   $_ = join( ',', @F );
258               }
259               continue {
260                   die "-p destination: $!\n" unless print $_;
261               }
262           }
263
264       With so many arguments (-i, -p, -a -F,, -l -e), this is about as bad as
265       it gets. And still one might find this way easier to document and
266       mantain than a crude one-liner stored in your ~/.bash_history or
267       similar.
268
269       Note: If you don't supply a name for your command, App::Rad will make
270       one up for you (cmd1, cmd2, ...). But don't do that, as you'll have a
271       hard time figuring out what that specific command does.
272
273       Another Note: App::Rad tries to adjust the command to its interface,
274       but please keep in mind this module is still in its early stages so
275       it's not guaranteed to work every time. *PLEASE* let me know via email
276       or RT bug request if your one-liner was not correctly translated into
277       an App::Rad command. Thanks!
278
279   exclude command_name
280       Removes the requested function from your program. Note that this will
281       delete the actual code from your program, so be *extra* careful. It is
282       strongly recommended that you do not use this command and either remove
283       the subroutine yourself or add the function to your excluded list
284       inside setup().
285
286       Note that built-in commands such as 'help' cannot be removed via
287       exclude. They have to be added to your excluded list inside setup().
288

ROLLING YOUR OWN COMMANDS

290       Creating a new command is as easy as writing any sub inside your
291       program. Some names ("setup", "default", "invalid", "pre_process",
292       "post_process" and "teardown") are reserved for special purposes (see
293       the Control Functions section of this document). App::Rad provides a
294       nice interface for reading command line input and writing formatted
295       output:
296
297   The Controller
298       Every command (sub) you create receives the controller object "$c"
299       (sometimes referred as "$self" in other projects) as an argument. The
300       controller is the main interface to App::Rad and has several methods to
301       easen your command manipulation and execution tasks.
302
303   Reading arguments
304       When someone types in a command, she may pass some arguments to it.
305       Those arguments can be accessed in four different ways, depending on
306       what you want. This way it's up to you to control which and how many
307       arguments (if at all) you want to receive and/or use. They are:
308
309       @ARGV
310
311       Perl's @ARGV array has all the arguments passed to your command,
312       without the command name (use "$c->cmd" for this) and without any
313       processing (even if you explicitly use "$c->getopt", which will change
314       $c->argv instead, see below). Since the command itself won't be in the
315       @ARGV parameters, you can use it in each command as if they were stand-
316       alone programs.
317
318       $c->options
319
320       App::Rad lets you automatically retrieve any POSIX syntax command line
321       options (getopt-style) passed to your command via the $c->options
322       method. This method returns a hash reference with keys as given
323       parameters and values as... well... values. The 'options' method
324       automatically supports two simple argument structures:
325
326       Extended (long) option. Translates "--parameter or --parameter=value"
327       into "$c->options->{parameter}". If no value is supplied, it will be
328       set to 1.
329
330       Single-letter option. Translates "-p" into "$c->options->{p}".
331
332       Single-letter options can be nested together, so "-abc" will be parsed
333       into "$c->options->{a}", "$c->options->{b}" and "$c->options{c}", while
334       "--abc" will be parsed into "$c->options->{abc}". We could, for
335       instance, create a dice-rolling command like this:
336
337           sub roll {
338               my $c = shift;
339
340               my $value = 0;
341               for ( 1..$c->options->{'times'} ) {
342                   $value += ( int(rand ($c->options->{'faces'}) + 1));
343               }
344               return $value;
345           }
346
347       And now you can call your 'roll' command like:
348
349           [user@host]$ ./myapp.pl roll --faces=6 --times=2
350
351       Note that App::Rad does not control which arguments can or cannot be
352       passed: they are all parsed into "$c->options" and it's up to you to
353       use whichever you want. For a more advanced use and control, see the
354       "$c->getopt" method below.
355
356       Also note that single-letter options will be set to 1. However, if a
357       user types them more than once, the value will be incremented
358       accordingly. For example, if a user calls your program like so:
359
360          [user@host]$ ./myapp.pl some_command -vvv
361
362       or
363
364          [user@host]$ ./myapp.pl some_command -v -v -v
365
366       then, in both cases, "$c->options->{v}" will be set to 3. This will let
367       you easily keep track of how many times any given option was chosen,
368       and still let you just check for definedness if you don't care about
369       that.
370
371       $c->argv
372
373       The array reference "$c->argv" contains every argument passed to your
374       command that have not been parsed into "$c->options". This is usually a
375       list of every provided argument that didn't start with a dash (-),
376       unless you've called "$c->getopt" and used something like 'param=s'
377       (again, see below).
378
379       $c->getopt (Advanced Getopt usage)
380
381       App::Rad is also smoothly integrated with Getopt::Long, so you can have
382       even more flexibility and power while parsing your command's arguments,
383       such as aliases and types. Call the "$c->getopt()" method anytime
384       inside your commands (or just once in your "pre_process" function to
385       always have the same interface) passing a simple array with your
386       options, and refer back to $c->options to see them. For instance:
387
388           sub roll {
389               my $c = shift;
390
391               $c->getopt( 'faces|f=i', 'times|t=i' )
392                   or $c->execute('usage') and return undef;
393
394               # and now you have $c->options->{'faces'}
395               # and $c->options->{'times'} just like above.
396           }
397
398       This becomes very handy for complex or feature-rich commands. Please
399       refer to the Getopt::Long module for more usage examples.
400
401       So, in order to manipulate and use any arguments, remember:
402
403       •     The given command name does not appear in the argument list;
404
405       •     All given arguments are in @ARGV
406
407       •     Automatically processed arguments are in "$c->options"
408
409       •     Non-processed arguments (the ones "$c->options" didn't catch) are
410             in $c->argv
411
412       •     You can use "$c->getopt" to have "Getopt::Long" parse your
413             arguments (it will not change @ARGV)
414
415   Sharing Data: "$c->stash"
416       The "stash" is a universal hash for storing data among your Commands:
417
418           $c->stash->{foo} = 'bar';
419           $c->stash->{herculoids} = [ qw(igoo tundro zok gloop gleep) ];
420           $c->stash->{application} = { name => 'My Application' };
421
422       You can use it for more granularity and control over your program. For
423       instance, you can email the output of a command if (and only if)
424       something happened:
425
426           sub command {
427               my $c = shift;
428               my $ret = do_something();
429
430               if ( $ret =~ /critical error/ ) {
431                   $c->stash->{mail} = 1;
432               }
433               return $ret;
434           }
435
436           sub post_process {
437               my $c = shift;
438
439               if ( $c->stash->{mail} ) {
440                   # send email alert...
441               }
442               else {
443                   print $c->output . "\n";
444               }
445           }
446
447   Returning output
448       Once you're through, return whatever you want to give as output for
449       your command:
450
451           my $ret = "Here's the list: ";
452           $ret .= join ', ', 1..5;
453           return $ret;
454
455           # this prints "Here's the list: 1, 2, 3, 4, 5"
456
457       App::Rad lets you post-process the returned value of every command, so
458       refrain from printing to STDOUT directly whenever possible as it will
459       give much more power to your programs. See the post_process() control
460       function further below in this document.
461

HELPER METHODS

463       App::Rad's controller comes with several methods to help you manage
464       your application easily. If you can think of any other useful command
465       that is not here, please drop me a line or RT request.
466
467   $c->execute( COMMAND_NAME )
468       Runs the given command. If no command is given, runs the one stored in
469       "$c->cmd". If the command does not exist, the 'default' command is ran
470       instead. Each execute() call also invokes pre_process and post_process,
471       so you can easily manipulate income and outcome of every command.
472
473   $c->cmd
474       Returns a string containing the name of the command (that is, the first
475       argument of your program), that will be called right after pre_process.
476
477       $c->command
478
479       Alias for "$c->cmd". This longer form is discouraged and may be removed
480       in future versions, as one may confuse it with the "$c->commands()"
481       method, explained below. You have been warned.
482
483   $c->commands()
484       Returns a list of available commands (functions) inside your program
485
486   $c->is_command ( COMMAND_NAME )
487       Returns 1 (true) if the given COMMAND_NAME is available, 0 (false)
488       otherwise.
489
490   $c->create_command_name()
491       Returns a valid name for a command (i.e. a name slot that's not been
492       used by your program). This goes in the form of 'cmd1', 'cmd2', etc.,
493       so don't use unless you absolutely have to. App::Rad, for instance,
494       uses this whenever you try to include (see below) a new command but do
495       not supply a name for it.
496
497   $c->load_config( FILE (FILE2, FILE3, ...) )
498       This method lets you easily load into your program one or more
499       configuration files written like this:
500
501           # comments and blank lines are discarded
502           key1 value1
503           key2:value2
504           key3=value3
505           key5           # stand-alone attribute (and inline-comment)
506
507   $c->config
508       Returns a hash reference with any loaded config values (see
509       "$c->load_config()" above).
510
511   $c->register ( NAME, CODEREF [, INLINE_HELP ])
512       Registers a coderef as a callable command. Note that you don't have to
513       call this in order to register a sub inside your program as a command,
514       run() will already do this for you - and if you don't want some
515       subroutines to be issued as commands you can always use
516       "$c->register_commands()" (note the plural) inside setup(). This is
517       just an interface to dinamically include commands in your programs. The
518       function returns the command name in case of success, undef otherwise.
519
520       It is also very useful for creating aliases for your commands:
521
522           sub setup {
523               my $c = shift;
524               $c->register_commands();
525
526               $c->register('myalias', \&command);
527           }
528
529           sub command { return "Hi!" }
530
531       and, on the command line:
532
533           [user@host]$ ./myapp.pl command
534           Hi!
535
536           [user@host]@ ./myapp.pl myalias
537           Hi!
538
539       The last parameter is optional and lets you add inline help to your
540       command:
541
542           $c->register('cmd_name', \&cmd_func, 'display secret of life');
543
544       $c->register_command ( NAME, CODEREF [, INLINE_HELP ] )
545
546       Longer alias for "$c->register()". It's use is disencouraged as one may
547       confuse it with "register_commands" (note the plural) below. Plus you
548       type more :) As such, this method may be removed in future versions.
549       You have been warned!
550
551   $c->register_commands()
552       This method, usually called during setup(), tells App::Rad to register
553       subroutines as valid commands. If called without any parameters, it
554       will register all subroutines in your main program as valid commands
555       (note that the default behavior of App::Rad is to ignore subroutines
556       starting with an underscore '_'). You can easily change this behavior
557       using some of the options below:
558
559       Adding single commands
560
561           $c->register_commands( qw/foo bar baz/ );
562
563       The code above will register only the subs "foo", "bar" and "baz" as
564       commands. Other subroutines will not be valid commands, so they can be
565       used as internal subs for your program. You can change this behavior
566       with the bundled options - see 'Adding several commands' and 'Putting
567       it all together' below.
568
569       Adding single commands (with inline help)
570
571           $c->register_commands(
572                   {
573                       dos2unix => 'convert text files from DOS to Unix format',
574                       unix2dos => 'convert text files from Unix to DOS format',
575                   }
576           );
577
578       You can pass a hash reference containing commands as keys and a small
579       help string as their values. The code above will register only the subs
580       "dos2unix" and "unix2dos", and the default help for your program will
581       become something like this:
582
583           [user@host]$ ./myapp.pl
584           Usage: myapp.pl command [arguments]
585
586           Available Commands:
587               dos2unix    convert text files from DOS to Unix format
588               help        show syntax and available commands
589               unix2dos    convert text files from Unix to DOS format
590
591       Adding several commands
592
593       You can pass a hash reference as an argument, letting you choose which
594       subroutines to add as commands. The following keys may be used (note
595       the dash preceding each key):
596
597       •   "-ignore_prefix": subroutine names starting with the given string
598           won't be added as commands
599
600       •   "-ignore_suffix": subroutine names ending with the given string
601           won't be added as commands
602
603       •   "-ignore_regexp": subroutine names matching the given regular
604           expression (as a string) won't be added as commands
605
606       For example:
607
608           use App::Rad;
609           App::Rad->run();
610
611           sub setup {
612               my $c = shift;
613               $c->register_commands( { -ignore_prefix => '_' } );
614           }
615
616           sub foo  {}  # will become a command
617           sub bar  {}  # will become a command
618           sub _baz {}  # will *NOT* become a command
619
620       This way you can easily segregate between commands and helper
621       functions, making your code even more reusable without jeopardizing the
622       command line interface (As of version 1.04, ignoring commands with
623       underscore '_' prefixes is also the default App::Rad behavior).
624
625       Putting it all together
626
627       You can combine some of the options above to have even more
628       flexibility:
629
630           $c->register_commands(
631                   'foo',
632                   { -ignore_suffix => 'foo' },
633                   { bar => 'all your command line are belong to us' },
634           );
635
636       The code above will register as commands all subs with names not ending
637       in 'foo', but it will register the 'foo' sub as well. It will also give
638       the 'bar' command the help string. This behavior is handy for
639       registering several commands and having a few exceptions, or to add
640       your commands and only have inline help for a few of them (as you see
641       fit).
642
643       You don't have to worry about the order of your elements passed,
644       App::Rad will figure them out for you in a DWIM fashion.
645
646           # this does the same as the code above
647           $c->register_commands(
648                   { bar => 'all your command line are belong to us' },
649                   'foo',
650                   { -ignore_suffix => 'foo' },
651           );
652
653       You can even bundle the hash reference to include your "cmd => help"
654       and special keys:
655
656           # this behaves the same way as the code above:
657           $c->register_commands(
658               'foo',
659               {
660                   -ignore_suffix => 'foo',
661                   bar => 'all your command line are belong to us',
662               }
663           );
664
665   $c->unregister_command ( NAME )
666       Longer alias for "$c->unregister()". The use of the shorter form is
667       encouraged, and this alias may be removed in future versions. You have
668       been warned.
669
670       $c->unregister ( NAME )
671
672       Unregisters a given command name so it's not available anymore. Note
673       that the subroutine will still be there to be called from inside your
674       program - it just won't be accessible via command line anymore.
675
676   $c->debug( MESSAGE )
677       Will print the given message on screen only if the debug flag is
678       enabled:
679
680           use App::Rad  qw( debug );
681
682       Note that, if debug is enabled, App::Rad itself will print several
683       debug messages stating its current flow, so you can easily find out
684       where everything is happening.
685
686   $c->plugins()
687       Returns a list of all loaded plugins, in the order in which they were
688       loaded.
689
690   $c->load_plugin( PLUGIN NAME )
691       This method will dinamically load the given plugin. The plugin needs to
692       be under the "App::Rad::Plugin" namespace, and the name should be
693       relative to this path (i.e. $c->load_plugin('MyPlugin') will try to
694       load 'App::Rad::Plugin::MyPlugin'). If you want to load a plugin by its
695       fully qualified name, you need to prepend a plus sign to the name
696       ('+Fully::Qualified::Plugin::Name'). This is an internal method and you
697       really should refrain from using it. Instead, plugins should be loaded
698       as parameters to the "use App::Rad" statement, as explained above.
699

CONTROL FUNCTIONS (to possibly override)

701       App::Rad implements some control functions which are expected to be
702       overridden by implementing them in your program. They are as follows:
703
704   setup()
705       This function is responsible for setting up what your program can and
706       cannot do, plus everything you need to set before actually running any
707       command (connecting to a database or host, check and validate things,
708       download a document, whatever). Note that, if you override setup(), you
709       *must* call "$c->register_commands()" or at least "$c->register()" so
710       your subs are classified as valid commands (check
711       $c->register_commands() above for more information).
712
713       Another interesting thing you can do with setup is to manipulate the
714       command list. For instance, you may want to be able to use the
715       "include" and "exclude" commands, but not let them available for all
716       users. So instead of writing:
717
718           use App::Rad qw(include exclude);
719           App::Rad->run();
720
721       you can write something like this:
722
723           use App::Rad;
724           App::Rad->run();
725
726           sub setup {
727               my $c = shift;
728               $c->register_commands();
729
730               # EUID is 'root'
731               if ( $> == 0 ) {
732                   $c->register('include', \&App::Rad::include);
733                   $c->register('exclude', \&App::Rad::exclude);
734               }
735           }
736
737       to get something like this:
738
739           [user@host]$ myapp.pl help
740           Usage: myapp.pl command [arguments]
741
742           Available Commands:
743              help
744
745           [user@host]$ sudo myapp.pl help
746           Usage: myapp.pl command [arguments]
747
748           Available Commands:
749              exclude
750              help
751              include
752
753   default()
754       If no command is given to your application, it will fall in here.
755       Please note that invalid (non-existant) command will fall here too, but
756       you can change this behavior with the invalid() function below
757       (although usually you don't want to).
758
759       Default's default (grin) is just an alias for the help command.
760
761           sub default {
762               my $c = shift;
763
764               # will fall here if the given
765               # command isn't valid.
766           }
767
768       You are free (and encouraged) to change the default behavior to
769       whatever you want. This is rather useful for when your program will
770       only do one thing, and as such it receives only parameters instead of
771       command names. In those cases, use the "default()" sub as your main
772       program's sub and parse the parameters with "$c->argv" and "$c->getopt"
773       as you would in any other command.
774
775   invalid()
776       This is a special function to provide even more flexibility while
777       creating your command line applications. This is called when the user
778       requests a command that does not exist. The built-in invalid() will
779       simply redirect itself to default() (see above), so usually you just
780       have to worry about this when you want to differentiate between "no
781       command given" (with or without getopt-like arguments) and "invalid
782       command given" (with or without getopt-like arguments).
783
784   teardown()
785       If implemented, this function is called automatically after your
786       application runs. It can be used to clean up after your operations,
787       removing temporary files, disconnecting a database connection
788       established in the setup function, logging, sending data over a
789       network, or even storing state information via Storable or whatever.
790
791   pre_process()
792       If implemented, this function is called automatically right before the
793       actual wanted command is called. This way you have an optional pre-run
794       hook, which permits functionality to be added, such as preventing some
795       commands to be run from a specific uid (e.g. root):
796
797           sub pre_process {
798               my $c = shift;
799
800               if ( $c->cmd eq 'some_command' and $> != 0 ) {
801                   $c->cmd = 'default'; # or some standard error message
802               }
803           }
804
805   post_process()
806       If implemented, this function is called automatically right after the
807       requested function returned. It receives the Controller object right
808       after a given command has been executed (and hopefully with some output
809       returned), so you can manipulate it at will. In fact, the default
810       "post_process" function is as goes:
811
812           sub post_process {
813               my $c = shift;
814
815               if ( $c->output() ) {
816                   print $c->output() . "\n";
817               }
818           }
819
820       You can override this function to include a default header/footer for
821       your programs (either a label or perhaps a "Content-type: " string),
822       parse the output in any ways you see fit (CPAN is your friend, as
823       usual), etc.
824

IMPORTANT NOTE ON PRINTING INSIDE YOUR COMMANDS

826       The post_process() function above is why your application should
827       *NEVER* print to STDOUT. Using print (or say, in 5.10) to send output
828       to STDOUT is exclusively the domain of the post_process() function.
829       Breaking this rule is a common source of errors. If you want your
830       functions to be interactive (for instance) and print everything
831       themselves, you should disable post-processing in setup(), or create an
832       empty post_process function or make your functions return undef (so
833       post_process() will only add a blank line to the output).
834

DIAGNOSTICS

836       If you see a '1' printed on the screen after a command is issued, it's
837       probably because that command is returning a "true" value instead of an
838       output string. If you don't want to return the command output for post
839       processing(you'll loose some nice features, though) you can return
840       undef or make post_process() empty.
841

CONFIGURATION AND ENVIRONMENT

843       App::Rad requires no configuration files or environment variables.
844

DEPENDENCIES

846       App::Rad depends only on 5.8 core modules (Carp for errors,
847       Getopt::Long for "$c->getopt", Attribute::Handlers for "help" and
848       O/B::Deparse for the "include" command).
849
850       If you have Perl::Tidy installed, the "include" command will tidy up
851       your code before inclusion.
852
853       The test suite depends on Test::More, FindBin and File::Temp, also core
854       modules.
855

INCOMPATIBILITIES

857       None reported.
858

BUGS AND LIMITATIONS

860       Please report any bugs or feature requests to "bug-app-easy at
861       rt.cpan.org", or through the web interface at
862       <http://rt.cpan.org/garu/ReportBug.html?Queue=App-Rad>.  I will be
863       notified, and then you'll automatically be notified of progress on your
864       bug as I make changes.
865

SUPPORT

867       You can find documentation for this module with the perldoc command.
868
869           perldoc App::Rad
870
871       Although this Module comes without any warraties whatsoever (see
872       DISCLAIMER below), I try really hard to provide some quality assurance
873       for the users. This means I not only try to close all reported bugs in
874       the minimum amount of time but I also try to find some on my own.
875
876       This version of App::Rad comes with 183 tests and I keep my eye
877       constantly on CPAN Testers
878       <http://www.cpantesters.org/show/App-Rad.html> to ensure it passes all
879       of them, in all platforms. You can send me your own App::Rad tests if
880       you feel I'm missing something and I'll hapilly add them to the
881       distribution.
882
883       Since I take user's feedback very seriously, I really hope you send me
884       any wishlist/TODO you'd like App::Rad to have (please try to send them
885       via RT so other people can give their own suggestions).
886
887       You can also look for information at:
888
889       •   RT: CPAN's request tracker
890
891           <http://rt.cpan.org/garu/Bugs.html?Dist=App-Rad>
892
893       •   AnnoCPAN: Annotated CPAN documentation
894
895           <http://annocpan.org/dist/App-Rad>
896
897       •   CPAN Ratings
898
899           <http://cpanratings.perl.org/d/App-Rad>
900
901       •   Search CPAN
902
903           <http://search.cpan.org/dist/App-Rad>
904
905   IRC
906          #app-rad  on irc.perl.org
907

TODO

909       This is a small list of features I plan to add in the near future (in
910       no particular order). Feel free to contribute with your wishlist and
911       comentaries!
912
913       •   Shell-like environment
914
915       •   Loadable commands (in an external container file)
916
917       •   Modularized commands (similar to App::Cmd::Commands ?)
918
919       •   app-starter
920
921       •   command inclusion by prefix, suffix and regexp (feature request by
922           fco)
923
924       •   command inclusion and exclusion also by attributes
925
926       •   some extra integration, maybe IPC::Cmd and IO::Prompt
927

AUTHOR

929       Breno G. de Oliveira, "<garu at cpan.org>"
930

CONTRIBUTORS

932       (in alphabetical order)
933
934       Ben Hengst
935
936       Fernando Correa
937
938       Flavio Glock
939
940       Thanks to everyone for contributing! Please let me know if I've skipped
941       your name by accident.
942

ACKNOWLEDGEMENTS

944       This module was inspired by Kenichi Ishigaki's presentation "Web is not
945       the only one that requires frameworks" during YAPC::Asia::2008 and the
946       modules it exposed (mainly App::Cmd and App::CLI).
947
948       Also, many thanks to CGI::App(now Titanium)'s Mark Stosberg and all the
949       Catalyst developers, as some of App::Rad's functionality was taken from
950       those (web) frameworks.
951
953       Copyright 2008 Breno G. de Oliveira "<garu at cpan.org>". All rights
954       reserved.
955
956       This module is free software; you can redistribute it and/or modify it
957       under the same terms as Perl itself. See perlartistic.
958

DISCLAIMER OF WARRANTY

960       BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
961       FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT
962       WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER
963       PARTIES PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND,
964       EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
965       WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
966       ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH
967       YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL
968       NECESSARY SERVICING, REPAIR, OR CORRECTION.
969
970       IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
971       WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
972       REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENCE, BE LIABLE
973       TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL, OR
974       CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE
975       SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING
976       RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A
977       FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF
978       SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
979       DAMAGES.
980
981
982
983perl v5.36.0                      2023-01-19                       App::Rad(3)
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