Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
Term::UI(3)	      User Contributed Perl Documentation	   Term::UI(3)

NAME
       Term::UI	- Term::ReadLine UI made easy

SYNOPSIS
	   use Term::UI;
	   use Term::ReadLine;

	   my $term = Term::ReadLine->new('brand');

	   my $reply = $term->get_reply(
			   prompt => 'What is your favourite colour?',
			   choices => [qw|blue red green|],
			   default => 'blue',
	   );

	   my $bool = $term->ask_yn(
			       prompt => 'Do you like cookies?',
			       default => 'y',
		       );

	   my $string =	q[some_command -option --no-foo	--quux='this thing'];

	   my ($options,$munged_input) = $term->parse_options($string);

	   ### don't have Term::UI issue warnings -- default is	'1'
	   $Term::UI::VERBOSE =	0;

	   ### always pick the default (good for non-interactive terms)
	   ### -- default is '0'
	   $Term::UI::AUTOREPLY	= 1;

	   ### Retrieve	the entire session as a	printable string:
	   $hist = Term::UI::History->history_as_string;
	   $hist = $term->history_as_string;

DESCRIPTION
       "Term::UI" is a transparent way of eliminating the overhead of having
       to format a question and	then validate the reply, informing the user if
       the answer was not proper and re-issuing	the question.

       Simply give it the question you want to ask, optionally with choices
       the user	can pick from and a default and	"Term::UI" will	DWYM.

       For asking a yes	or no question,	there's	even a shortcut.

HOW IT WORKS
       "Term::UI" places itself	at the back of the "Term::ReadLine" @ISA
       array, so you can call its functions through your term object.

       "Term::UI" uses "Term::UI::History" to record all interactions with the
       commandline. You	can retrieve this history, or alter the	filehandle the
       interaction is printed to. See the "Term::UI::History" manpage or the
       "SYNOPSIS" for details.

METHODS
   $reply = $term->get_reply( prompt =>	'question?', [choices => \@list,
       default => $list[0], multi => BOOL, print_me => "extra text to print &
       record",	allow => $ref] );
       "get_reply" asks	a user a question, and then returns the	reply to the
       caller. If the answer is	invalid	(more on that below), the question
       will be reposed,	until a	satisfactory answer has	been entered.

       You have	the option of providing	a list of choices the user can pick
       from using the "choices"	argument. If the answer	is not in the list of
       choices presented, the question will be reposed.

       If you provide a	"default"  answer, this	will be	returned when either
       $AUTOREPLY is set to true, (see the "GLOBAL VARIABLES" section further
       below), or when the user	just hits "enter".

       You can indicate	that the user is allowed to enter multiple answers by
       toggling	the "multi" flag. Note that a list of answers will then	be
       returned	to you,	rather than a simple string.

       By specifying an	"allow"	handler, you can yourself validate the answer
       a user gives. This can be any of	the types that the Params::Check
       "allow" function	allows,	so please refer	to that	manpage	for details.

       Finally,	you have the option of adding a	"print_me" argument, which is
       simply printed before the prompt. It's printed to the same file handle
       as the rest of the questions, so	you can	use this to keep track of a
       full session of Q&A with	the user, and retrieve it later	using the
       "Term::UI->history_as_string" function.

       See the "EXAMPLES" section for samples of how to	use this function.

   $bool = $term->ask_yn( prompt => "your question", [default => (y|1,n|0),
       print_me	=> "extra text to print	& record"] )
       Asks a simple "yes" or "no" question to the user, returning a boolean
       indicating "true" or "false" to the caller.

       The "default" answer will automatically returned, if the	user hits
       "enter" or if $AUTOREPLY	is set to true.	See the	"GLOBAL	VARIABLES"
       section further below.

       Also, you have the option of adding a "print_me"	argument, which	is
       simply printed before the prompt. It's printed to the same file handle
       as the rest of the questions, so	you can	use this to keep track of a
       full session of Q&A with	the user, and retrieve it later	using the
       "Term::UI->history_as_string" function.

       See the "EXAMPLES" section for samples of how to	use this function.

   ($opts, $munged) = $term->parse_options( STRING );
       "parse_options" will convert all	options	given from an input string to
       a hash reference. If called in list context it will also	return the
       part of the input string	that it	found no options in.

       Consider	this example:

	   my $str =   q[command --no-foo --baz	--bar=0	--quux=bleh ] .
		       q[--option="some'thing" -one-dash -single=blah' arg];

	   my ($options,$munged) =  $term->parse_options($str);

	   ### $options	would contain: ###
	   $options = {
		       'foo'	   => 0,
		       'bar'	   => 0,
		       'one-dash'  => 1,
		       'baz'	   => 1,
		       'quux'	   => 'bleh',
		       'single'	   => 'blah\'',
		       'option'	   => 'some\'thing'
	   };

	   ### and this	is the munged version of the input string,
	   ### ie what's left of the input minus the options
	   $munged = 'command arg';

       As you can see, you can either use a single or a	double "-" to indicate
       an option.  If you prefix an option with	"no-" and do not give it a
       value, it will be set to	0.  If it has no prefix	and no value, it will
       be set to 1.  Otherwise,	it will	be set to its value. Note also that it
       can deal	fine with single/double	quoting	issues.

   $str	= $term->history_as_string
       Convenience wrapper around "Term::UI::History->history_as_string".

       Consult the "Term::UI::History" man page	for details.

GLOBAL VARIABLES
       The behaviour of	Term::UI can be	altered	by changing the	following
       global variables:

   $Term::UI::VERBOSE
       This controls whether Term::UI will issue warnings and explanations as
       to why certain things may have failed. If you set it to 0, Term::UI
       will not	output any warnings.  The default is 1;

   $Term::UI::AUTOREPLY
       This will make every question be	answered by the	default, and warn if
       there was no default provided. This is particularly useful if your
       program is run in non-interactive mode.	The default is 0;

   $Term::UI::INVALID
       This holds the string that will be printed when the user	makes an
       invalid choice.	You can	override this string from your program if you,
       for example, wish to do localization.  The default is "Invalid
       selection, please try again: "

   $Term::UI::History::HISTORY_FH
       This is the filehandle all the print statements from this module	are
       being sent to. Please consult the "Term::UI::History" manpage for
       details.

       This defaults to	*STDOUT.

EXAMPLES
   Basic get_reply sample
	   ### ask a user (with	an open	question) for their favourite colour
	   $reply = $term->get_reply( prompt =>	'Your favourite	colour?	);

       which would look	like:

	   Your	favourite colour?

       and $reply would	hold the text the user typed.

   get_reply with choices
	   ### now provide a list of choices, so the user has to pick one
	   $reply = $term->get_reply(
		       prompt  => 'Your	favourite colour?',
		       choices => [qw|red green	blue|] );

       which would look	like:

	     1>	red
	     2>	green
	     3>	blue

	   Your	favourite colour?

       $reply will hold	one of the choices presented. "Term::UI" will repose
       the question if the user	attempts to enter an answer that's not in the
       list of choices.	The string presented is	held in	the $Term::UI::INVALID
       variable	(see the "GLOBAL VARIABLES" section for	details.

   get_reply with choices and default
	   ### provide a sensible default option -- everyone loves blue!
	   $reply = $term->get_reply(
		       prompt  => 'Your	favourite colour?',
		       choices => [qw|red green	blue|],
		       default => 'blue' );

       which would look	like:

	     1>	red
	     2>	green
	     3>	blue

	   Your	favourite colour? [3]:

       Note the	default	answer after the prompt. A user	can now	just hit
       "enter" (or set $Term::UI::AUTOREPLY -- see the "GLOBAL VARIABLES"
       section)	and the	sensible answer	'blue' will be returned.

   get_reply using print_me & multi
	   ### allow the user to pick more than	one colour and add an
	   ### introduction text
	   @reply = $term->get_reply(
		       print_me	   => 'Tell us what colours you	like',
		       prompt	   => 'Your favourite colours?',
		       choices	   => [qw|red green blue|],
		       multi	   => 1	);

       which would look	like:

	   Tell	us what	colours	you like
	     1>	red
	     2>	green
	     3>	blue

	   Your	favourite colours?

       An answer of "3 2 1" would fill @reply with "blue green red"

   get_reply & allow
	   ### pose an open question, but do a custom verification on
	   ### the answer, which will only exit	the question loop, if
	   ### the answer matches the allow handler.
	   $reply = $term->get_reply(
		       prompt  => "What	is the magic number?",
		       allow   => 42 );

       Unless the user now enters 42, the question will	be reposed over	and
       over again. You can use more sophisticated "allow" handlers (even
       subroutines can be used). The "allow" handler is	implemented using
       "Params::Check"'s "allow" function. Check its manpage for details.

   an elaborate	ask_yn sample
	   ### ask a user if he	likes cookies. Default to a sensible 'yes'
	   ### and inform him first what cookies are.
	   $bool = $term->ask_yn( prompt   => 'Do you like cookies?',
				  default  => 'y',
				  print_me => 'Cookies are LOVELY!!!' );

       would print:

	   Cookies are LOVELY!!!
	   Do you like cookies?	[Y/n]:

       If a user then simply hits "enter", agreeing with the default, $bool
       would be	set to "true". (Simply hitting 'y' would also return "true".
       Hitting 'n' would return	"false")

       We could	later retrieve this interaction	by printing out	the Q&A
       history as follows:

	   print $term->history_as_string;

       which would then	print:

	   Cookies are LOVELY!!!
	   Do you like cookies?	[Y/n]:	y

       There's a chance	we're doing this non-interactively, because a console
       is missing, the user indicated he just wanted the defaults, etc.

       In this case, simply setting $Term::UI::AUTOREPLY to true, will return
       from every question with	the default answer set for the question.  Do
       note that if "AUTOREPLY"	is true, and no	default	is set,	"Term::UI"
       will warn about this and	return "undef".

See Also
       "Params::Check",	"Term::ReadLine", "Term::UI::History"

BUG REPORTS
       Please report bugs or other issues to <bug-term-ui@rt.cpan.org<gt>.

AUTHOR
       This module by Jos Boumans <kane@cpan.org>.

COPYRIGHT
       This library is free software; you may redistribute and/or modify it
       under the same terms as Perl itself.

perl v5.32.0			  2015-05-25			   Term::UI(3)

NAME | SYNOPSIS | DESCRIPTION | HOW IT WORKS | METHODS | GLOBAL VARIABLES | EXAMPLES | See Also | BUG REPORTS | AUTHOR | COPYRIGHT

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=Term::UI&sektion=3&manpath=FreeBSD+12.2-RELEASE+and+Ports>

home | help