Term::Prompt(3) User Contributed Perl Documentation Term::Prompt(3)NAMETerm::Prompt - Perl extension for prompting a user for information
SYNOPSIS
use Term::Prompt;
$value = prompt(...);
use Term::Promptqw(termwrap);
print termwrap(...);
$Term::Prompt::MULTILINE_INDENT = '';
PREREQUISITES
You must have Text::Wrap and Term::ReadKey available on your system.
DESCRIPTION
This main function of this module is to accept interactive input. You
specify the type of inputs allowed, a prompt, help text and defaults
and it will deal with the user interface, (and the user!), by
displaying the prompt, showing the default, and checking to be sure
that the response is one of the legal choices. Additional 'types' that
could be added would be a phone type, a social security type, a generic
numeric pattern type...
FUNCTIONS
prompt
This is the main function of the module. Its first argument determines
its usage and is one of the following single characters:
x: do not care
a: alpha-only
n: numeric-only
i: ignore case
c: case sensitive
r: ranged by the low and high values
f: floating-point
y: yes/no
e: regular expression
s: sub (actually, a code ref, but 'c' was taken)
p: password (keystrokes not echoed)
m: menu
x: do not care
$result = prompt('x', 'text prompt', 'help prompt', 'default' );
$result is whatever the user types.
a: alpha-only
$result = prompt('a', 'text prompt', 'help prompt', 'default' );
$result is a single 'word' consisting of [A-Za-z] only. The
response is rejected until it conforms.
n: numeric-only
$result = prompt('n', 'text prompt', 'help prompt', 'default' );
The result will be a positive integer or 0.
$result = prompt('-n', 'text prompt', 'help prompt', 'default' );
The result will be a negative integer or 0.
$result = prompt('+-n', 'text prompt', 'help prompt', 'default' );
The result will be a any integer or 0.
i: ignore case
$result = prompt('i', 'text prompt', 'help prompt', 'default',
'legal_options-ignore-case-list');
c: case sensitive
$result = prompt('c', 'text prompt', 'help prompt', 'default',
'legal_options-case-sensitive-list');
r: ranged by the low and high values
$result = prompt('r', 'text prompt', 'help prompt', 'default',
'low', 'high');
f: floating-point
$result = prompt('f', 'text prompt', 'help prompt', 'default');
The result will be a floating-point number.
y: yes/no
$result = prompt('y', 'text prompt', 'help prompt', 'default')
The result will be 1 for y, 0 for n. A default not starting with y,
Y, n or N will be treated as y for positive, n for negative.
e: regular expression
$result = prompt('e', 'text prompt', 'help prompt', 'default',
'regular expression');
The regular expression has and implicit ^ and $ surrounding it;
just put in .* before or after if you need to free it up before or
after.
s: sub
$result = prompt('s', 'text prompt', 'help prompt', 'default',
sub { warn 'Your input was ' . shift; 1 });
$result = prompt('s', 'text prompt', 'help prompt', 'default',
\&my_custom_validation_handler);
User reply is passed to given code reference as first and only
argument. If code returns true, input is accepted.
p: password
$result = prompt('p', 'text prompt', 'help prompt', 'default' );
$result is whatever the user types, but the characters are not
echoed to the screen.
m: menu
@results = prompt(
'm',
{
prompt => 'text prompt',
title => 'My Silly Menu',
items => [ qw (foo bar baz biff spork boof akak) ],
order => 'across',
rows => 1,
cols => 1,
display_base => 1,
return_base => 0,
accept_multiple_selections => 0,
accept_empty_selection => 0,
ignore_whitespace => 0,
separator => '[^0-9]+'
},
'help prompt',
'default');
This will create a menu with numbered items to select. You replace
the normal prompt argument with a hash reference containing this
information:
prompt
The prompt string.
title
Text printed above the menu.
items
An array reference to the list of text items to display. They
will be numbered ascending in the order presented.
order
If set to 'across', the item numbers run across the menu:
1) foo 2) bar 3) baz
4) biff 5) spork 6) boof
7) akak
If set to 'down', the item numbers run down the menu:
1) foo 4) biff 7) akak
2) bar 5) spork
3) baz 6) boof
'down' is the default.
rows,cols
Forces the number of rows and columns. Otherwise, the number of
rows and columns is determined from the number of items and the
maximum length of an item with its number.
Usually, you would set rows = 1 or cols = 1 to force a non-
wrapped layout. Setting both in tandem is untested. Cavet
programmer.
display_base,return_base
Internally, the items are indexed the 'Perl' way, from 0 to
scalar -1. The display_base is the number added to the index on
the menu display. The return_base is the number added to the
index before the reply is returned to the programmer.
The defaults are 1 and 0, respectively.
accept_multiple_selections
When set to logical true (1 will suffice), more than one menu
item may be selected. The return from prompt() will be an array
or array ref, depending on how it is called.
The default is 0. The return value is a single scalar
containing the selection.
accept_empty_selection
When set to logical true (1 will suffice), if no items are
selected, the menu will not be repeated and the 'empty'
selection will be returned. The value of an 'empty' selection
is an empty array or a reference to same, if
accept_multiple_selections is in effect, or undef if not.
separator
A regular expression that defines what characters are allowed
between multiple responses. The default is to allow all non-
numeric characters to be separators. That can cause problems
when a user mistakenly enters the lead letter of the menu item
instead of the item number. You are better off replacing the
default with something more reasonable, such as:
[,] ## Commas
[,/] ## Commas or slashes
[,/\s] ## Commas or slashes or whitespace
ignore_whitespace
When set, allows spaces between menu responses to be ignored,
so that
1, 5, 6
is collapsed to
1,5,6
before parsing. NOTE: Do not set this option if you are
including whitespace as a legal separator.
ignore_empties
When set, consecutive separators will not result in an empty
entry. For example, without setting this option:
1,,8,9
will result in a return of
(1,'',8,9)
When set, the return will be:
(1,8,9)
which is probably what you want.
Other Functions and Variables
termwrap
Part of Term::Prompt is the optionally exported function termwrap,
which is used to wrap lines to the width of the currently selected
filehandle (or to STDOUT or STDERR if the width of the current
filehandle cannot be determined). It uses the GetTerminalSize
function from Term::ReadKey then Text::Wrap.
MULTILINE_INDENT
This package variable holds the string to be used to indent lines
of a multiline prompt, after the first line. The default is "\t",
which is how the module worked before the variable was exposed. If
you do not want ANY indentation:
$Term::Prompt::MULTILINE_INDENT = '';
Text and Help Prompts
What, you might ask, is the difference between a 'text prompt' and a
'help prompt'? Think about the case where the 'legal_options' look
something like: '1-1000'. Now consider what happens when you tell
someone that '0' is not between 1-1000 and that the possible choices
are: :) 1 2 3 4 5 ..... This is what the 'help prompt' is for.
It will work off of unique parts of 'legal_options'.
Changed by Allen - if you capitalize the type of prompt, it will be
treated as a true 'help prompt'; that is, it will be printed ONLY if
the menu has to be redisplayed due to and entry error. Otherwise, it
will be treated as a list of options and displayed only the first time
the menu is displayed.
Capitalizing the type of prompt will also mean that a return may be
accepted as a response, even if there is no default; whether it
actually is will depend on the type of prompt. Menus, for example, do
not do this.
AUTHOR
Original Author: Mark Henderson (henderson@mcs.anl.gov or
systems@mcs.anl.gov). Derived from im_prompt2.pl, from anlpasswd (see
ftp://info.mcs.anl.gov/pub/systems/), with permission.
Contributors:
E. Allen Smith (easmith@beatrice.rutgers.edu): Revisions for Perl 5,
additions of alternative help text presentation, floating point type,
regular expression type, yes/no type, line wrapping and regular
expression functionality added by E. Allen Smith.
Matthew O. Persico (persicom@cpan.org): Addition of menu functionality
and $Term::Prompt::MULTILINE_INDENT.
Tuomas Jormola (tjormola@cc.hut.fi): Addition of code refs.
Current maintainer: Matthew O. Persico (persicom@cpan.org)
SEE ALSO
perl, Term::ReadKey, and Text::Wrap.
COPYRIGHT AND LICENSE
Copyright (C) 2004 by Matthew O. Persico
This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself, either Perl version 5.6.1 or, at
your option, any later version of Perl 5 you may have available.
perl v5.14.1 2011-06-20 Term::Prompt(3)
