Term::Choose - Choose items from a list.
Version 1.020
use 5.10.1; use Term::Choose qw(choose); my $array_ref = [ qw( one two three four five ) ]; my $choice = choose( $array_ref ); # single choice say $choice; my @choices = choose( [ 1 .. 100 ], { right_justify => 1 } ); # multiple choice say "@choices"; choose( [ 'Press ENTER to continue' ], { prompt => 0 } ); # no choice
Choose from a list of items.
Based on the choose function from the Term::Clui module - for more details see "MOTIVATION".
Nothing by default.
use Term::Choose qw(choose);
$scalar = choose( $array_ref [, \%options] ); @array = choose( $array_ref [, \%options] ); choose( $array_ref [, \%options] );
choose expects as a first argument an array reference. The array the reference refers to holds the list items available for selection (in void context no selection can be made).
The array the reference - passed with the first argument - refers to is called in the documentation simply array resp. elements (of the array).
Options can be passed with a hash reference as a second (optional) argument.
If choose is called in a scalar context, the user can choose an item by using the "move-around-keys" and confirming with "Return".
choose then returns the chosen item.
If choose is called in an list context, the user can also mark an item with the "SpaceBar".
choose then returns - when "Return" is pressed - the list of marked items including the highlighted item.
If choose is called in an void context, the user can move around but mark nothing; the output shown by choose can be closed with "Return".
Called in void context choose returns nothing.
If the items of the list don't fit on the screen, the user can scroll to the next (previous) page(s).
If the window size is changed, then as soon as the user enters a keystroke choose rewrites the screen. In list context marked items are reset.
The "q" key returns undef or an empty list in list context.
With a mouse_mode enabled (and if supported by the terminal) the item can be chosen with the left mouse key, in list context the right mouse key can be used instead the "SpaceBar" key.
Keys to move around: arrow keys (or hjkl), Tab, BackSpace (or Shift-Tab or Ctrl-H), PageUp and PageDown (or Ctrl+B/Ctrl+F).
For the output on the screen the array elements are modified:
if an element is not defined the value from the option undef is assigned to the element.
if an element holds an empty string the value from the option empty_string is assigned to the element.
white-spaces in elements are replaced with simple spaces.
$element =~ s/\p{Space}/ /g;
control characters are removed.
$element =~ s/\p{Cntrl}//g;
if the length of an element is greater than the width of the screen the element is cut.
$element = substr( $element, 0, $allowed_length - 3 ) . '...';*
* Term::Choose uses its own function to cut strings which uses print columns for the arithmetic.
All these modifications are made on a copy of the original array so choose returns the chosen elements as they were passed to the function without modifications.
All options are optional.
Defaults may change in a future release.
Options which expect a number as their value expect integers.
There is a general upper limit of 1_000_000_000 for options which expect a number as their value and where no upper limit is mentioned.
If prompt is undefined a default prompt-string will be shown.
If prompt is 0 no prompt-line will be shown.
default in list and scalar context: 'Your choice:'
default in void context: 'Close with ENTER'
From broad to narrow: 0 > 1 > 2 > 3
0 - layout off
.----------------------. .----------------------. .----------------------. .----------------------. | .. .. .. .. .. .. .. | | .. .. .. .. .. .. .. | | .. .. .. .. .. .. .. | | .. .. .. .. .. .. .. | | | | .. .. .. .. .. .. .. | | .. .. .. .. .. .. .. | | .. .. .. .. .. .. .. | | | | | | .. .. .. .. .. | | .. .. .. .. .. .. .. | | | | | | | | .. .. .. .. .. .. .. | | | | | | | | .. .. .. .. .. .. .. | | | | | | | | .. .. .. .. .. .. .. | '----------------------' '----------------------' '----------------------' '----------------------'
1 - layout "H" (default)
.----------------------. .----------------------. .----------------------. .----------------------. | .. .. .. .. .. .. .. | | .. .. .. .. .. | | .. .. .. .. .. .. | | .. .. .. .. .. .. .. | | | | .. .. .. .. .. | | .. .. .. .. .. .. | | .. .. .. .. .. .. .. | | | | .. .. | | .. .. .. .. .. .. | | .. .. .. .. .. .. .. | | | | | | .. .. .. .. .. .. | | .. .. .. .. .. .. .. | | | | | | .. .. .. | | .. .. .. .. .. .. .. | | | | | | | | .. .. .. .. .. .. .. | '----------------------' '----------------------' '----------------------' '----------------------'
2 - layout "V"
.----------------------. .----------------------. .----------------------. .----------------------. | .. | | .. .. | | .. .. .. .. | | .. .. .. .. .. .. .. | | .. | | .. .. | | .. .. .. .. | | .. .. .. .. .. .. .. | | .. | | .. .. | | .. .. .. .. | | .. .. .. .. .. .. .. | | .. | | .. | | .. .. .. | | .. .. .. .. .. .. .. | | .. | | | | .. .. .. | | .. .. .. .. .. .. .. | | .. | | | | | | .. .. .. .. .. .. .. | '----------------------' '----------------------' '----------------------' '----------------------'
3 - all in a single column
.----------------------. .----------------------. .----------------------. .----------------------. | .. | | .. | | .. | | .. | | .. | | .. | | .. | | .. | | .. | | .. | | .. | | .. | | | | .. | | .. | | .. | | | | | | .. | | .. | | | | | | | | .. | '----------------------' '----------------------' '----------------------' '----------------------'
If set, restricts the screen width to the integer value of screen_width percentage of the effective screen width.
If the integer value of screen_width percentage of the screen width is zero the virtual screen width is set to one screen column.
If not defined all the screen width is used.
Allowed values: from 1 to 100
(default: undef)
This option will be removed with the next release - use order instead.
If the output has more than one row and more than one column:
0 - elements are ordered horizontally
1 - elements are ordered vertically (default)
This option will be removed with the next release - use justify instead.
0 - elements ordered in columns are left justified (default)
1 - elements ordered in columns are right justified
2 - elements ordered in columns are centered
Sets the number of whitespaces between columns. (default: 2)
Allowed values: 0 or greater
Sets the number of whitespaces between elements if we have only one row. (default: 3)
0 - off (default)
1 - clears the screen before printing the choices
If the length* of the element with the largest length is known before calling choose it can be passed with this option.
If length_longest is set, then choose doesn't calculate the length of the longest element itself but uses the value passed with this option.
If length_longest is set to a value less than the length of the longest element all elements which a length greater than this value will be cut.
A larger value than the length of the longest element wastes space on the screen.
If the value of length_longest is greater than the screen width length_longest will be set to the screen width.
* length means the number of print columns the element will use on the terminal.
Allowed values: 1 or greater
With the option default can be selected an element, which will be highlighted as the default instead of the first element.
default expects a zero indexed value, so e.g. to highlight the third element the value would be 2.
If the passed value is greater than the index of the last array element the first element is highlighted.
1 - return the index of the chosen element instead of the chosen element resp. the indices of the chosen elements instead of the chosen elements.
0 - off
1 - print the page number on the bottom of the screen if there is more then one page. (default)
0 - no mouse mode (default)
1 - mouse mode 1003 enabled
2 - mouse mode 1003 enabled; maxcols/maxrows limited to 224 (mouse mode 1003 doesn't work above 224)
3 - extended mouse mode (1005) - uses utf8
4 - extended SGR mouse mode (1006) - mouse mode 1003 is used if mouse mode 1006 is not supported
Sets the string displayed on the screen instead an undefined element.
default: '<undef>'
Sets the string displayed on the screen instead an empty string.
default: '<empty>'
1 - on
0 - keep the terminals highlighting of the cursor position
1 - hide the terminals highlighting of the cursor position (default)
Sets the maximal allowed length of the array. (default: 100_000)
With no arguments choose dies.
If the first argument is not a array reference choose dies.
If the array referred by the first argument is empty choose returns undef resp. an empty list and issues a warning.
If the array referred by the first argument has more than limit elements (default 100_000) choose warns and uses the first limit array elements.
If the (optional) second argument is not a hash reference choose dies.
If an option does not exist choose warns.
If an option value is not valid choose warns an falls back to the default value.
Requires Perl Version 5.10.1 or greater.
Used modules not provided as core modules:
Term::ReadKey
Unicode::GCString
choose expects decoded strings as array elements.
It is needed a terminal that uses a monospaced font.
Term::Choose makes use of the Perl signal handling as described in perlipc/Signals. It is needed an operating system which knows the WINCH signal: choose uses SIGWINCH to check if the windows size has changed.
The Terminal needs to understand the following ANSI escape sequences:
"\e[A" Cursor Up "\e[C" Cursor Forward "\e[0J" Clear to End of Screen (Erase Data) "\e[0m" Normal/Reset "\e[1m" Bold "\e[4m" Underline "\e[7m" Inverse
If the option "hide_cursor" is enabled:
"\e[?25l" Hide Cursor "\e[?25h" Show Cursor
If the option "clear_screen" is enabled:
"\e[2J" Clear Screen (Erase Data) "\e[1;1H" Go to Top Left (Cursor Position)
If a "mouse_mode" is enabled:
"\e[6n" Get Cursor Position (Device Status Report)
Mouse Tracking: The escape sequences
"\e[?1003h", "\e[?1005h", "\e[?1006h"
and
"\e[?1003l", "\e[?1005l", "\e[?1006l"
are used to enable/disable the different mouse modes.
The reason for writing Term::Choose was to get something like Term::Clui::choose but with a nicer output in the case the list doesn't fit in one row.
If the list does not fit in one row, choose from Term::Clui puts the items on the screen without ordering the items in columns. Term::Choose arranges the items in columns which makes it easier for me to find items and easier to navigate on the screen.
Term::Clui's choose expects a question as the first argument, and then the list of items. With Term::Choose the available choices are passed with an array reference as first argument. Options can be passed with a hash reference as an optional second argument. The question can be passed with the option prompt.
As mentioned above choose from Term::Clui does not order the elements in columns if there is more than one row on the screen while Term::Choose arranges the elements in such situations in columns.
Another difference is how lists which don't fit on the screen are handled. Term::Clui::choose asks the user to enter a substring as a clue. As soon as the matching items will fit, they are displayed as normal. choose from Term::Choose skips - when scrolling and reaching the end (resp. the begin) of the screen - to the next (resp. previous) page.
Strings with characters where length(character)* is not equal to the number of print columns of the respective character might break the output from Term::Clui. To make Term::Choose's choose function work with such kind of Unicode strings it uses the method columns from Unicode::GCString to determine the string length.
* Perl builtin function length.
Term::Clui's choose prints and returns the chosen items while choose from Term::Choose only returns the chosen items.
Term::Clui disables the mouse mode if the environment variable CLUI_MOUSE is set to off. In Term::Choose the mouse mode is set with the option mouse_mode.
Term::Clui provides a speaking interface, offers a bundle of functions and has a fallback to work when only Perl core modules are available.
The choose function from Term::Clui can remember choices made in scalar context and allows multiline question - the first line is put on the top, the subsequent lines are displayed below the list.
These differences refer to Term::Clui version 1.66. For a more precise description of Term::Clui consult its own documentation.
You can find documentation for this module with the perldoc command.
perldoc Term::Choose
Matthäus Kiem <cuer2s@gmail.com>
Based on and inspired by the choose function from the Term::Clui module.
Thanks to the Perl-Community.de and the people form stackoverflow for the help.
Copyright 2012 Matthäus Kiem.
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
To install Term::Choose, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Term::Choose
CPAN shell
perl -MCPAN -e shell install Term::Choose
For more information on module installation, please visit the detailed CPAN module installation guide.