1Term::UI(3)           User Contributed Perl Documentation          Term::UI(3)
2
3
4

NAME

6       Term::UI - Term::ReadLine UI made easy
7

SYNOPSIS

9           use Term::UI;
10           use Term::ReadLine;
11
12           my $term = Term::ReadLine->new('brand');
13
14           my $reply = $term->get_reply(
15                           prompt => 'What is your favourite colour?',
16                           choices => [qw|blue red green|],
17                           default => 'blue',
18           );
19
20           my $bool = $term->ask_yn(
21                               prompt => 'Do you like cookies?',
22                               default => 'y',
23                       );
24
25
26           my $string = q[some_command -option --no-foo --quux='this thing'];
27
28           my ($options,$munged_input) = $term->parse_options($string);
29
30
31           ### don't have Term::UI issue warnings -- default is '1'
32           $Term::UI::VERBOSE = 0;
33
34           ### always pick the default (good for non-interactive terms)
35           ### -- default is '0'
36           $Term::UI::AUTOREPLY = 1;
37
38           ### Retrieve the entire session as a printable string:
39           $hist = Term::UI::History->history_as_string;
40           $hist = $term->history_as_string;
41

DESCRIPTION

43       "Term::UI" is a transparent way of eliminating the overhead of having
44       to format a question and then validate the reply, informing the user if
45       the answer was not proper and re-issuing the question.
46
47       Simply give it the question you want to ask, optionally with choices
48       the user can pick from and a default and "Term::UI" will DWYM.
49
50       For asking a yes or no question, there's even a shortcut.
51

HOW IT WORKS

53       "Term::UI" places itself at the back of the "Term::ReadLine" @ISA
54       array, so you can call its functions through your term object.
55
56       "Term::UI" uses "Term::UI::History" to record all interactions with the
57       commandline. You can retrieve this history, or alter the filehandle the
58       interaction is printed to. See the "Term::UI::History" manpage or the
59       "SYNOPSIS" for details.
60

METHODS

62   $reply = $term->get_reply( prompt => 'question?', [choices => \@list,
63       default => $list[0], preput => "text to put as default user input",
64       multi => BOOL, print_me => "extra text to print & record", allow =>
65       $ref] );
66       "get_reply" asks a user a question, and then returns the reply to the
67       caller. If the answer is invalid (more on that below), the question
68       will be reposed, until a satisfactory answer has been entered.
69
70       You have the option of providing a list of choices the user can pick
71       from using the "choices" argument. If the answer is not in the list of
72       choices presented, the question will be reposed.
73
74       If you provide a "default"  answer, this will be returned when either
75       $AUTOREPLY is set to true, (see the "GLOBAL VARIABLES" section further
76       below), or when the user just hits "enter".
77
78       The "preput" argument allows to specify a text that will be inserted to
79       the prompt line as the initial input which may be edited, deleted or
80       accepted by the user. If you supply the empty string as the "preput"
81       argument then the "default" value will be preputted. It will only work
82       if the underlying readline module provide support for it (now it is
83       supported only by the "Term::Readline::Gnu").
84
85       You can indicate that the user is allowed to enter multiple answers by
86       toggling the "multi" flag. Note that a list of answers will then be
87       returned to you, rather than a simple string.
88
89       By specifying an "allow" handler, you can yourself validate the answer
90       a user gives. This can be any of the types that the Params::Check
91       "allow" function allows, so please refer to that manpage for details.
92
93       Finally, you have the option of adding a "print_me" argument, which is
94       simply printed before the prompt. It's printed to the same file handle
95       as the rest of the questions, so you can use this to keep track of a
96       full session of Q&A with the user, and retrieve it later using the
97       "Term::UI->history_as_string" function.
98
99       See the "EXAMPLES" section for samples of how to use this function.
100
101   $bool = $term->ask_yn( prompt => "your question", [default => (y|1,n|0),
102       print_me => "extra text to print & record"] )
103       Asks a simple "yes" or "no" question to the user, returning a boolean
104       indicating "true" or "false" to the caller.
105
106       The "default" answer will automatically returned, if the user hits
107       "enter" or if $AUTOREPLY is set to true. See the "GLOBAL VARIABLES"
108       section further below.
109
110       Also, you have the option of adding a "print_me" argument, which is
111       simply printed before the prompt. It's printed to the same file handle
112       as the rest of the questions, so you can use this to keep track of a
113       full session of Q&A with the user, and retrieve it later using the
114       "Term::UI->history_as_string" function.
115
116       See the "EXAMPLES" section for samples of how to use this function.
117
118   ($opts, $munged) = $term->parse_options( STRING );
119       "parse_options" will convert all options given from an input string to
120       a hash reference. If called in list context it will also return the
121       part of the input string that it found no options in.
122
123       Consider this example:
124
125           my $str =   q[command --no-foo --baz --bar=0 --quux=bleh ] .
126                       q[--option="some'thing" -one-dash -single=blah' arg];
127
128           my ($options,$munged) =  $term->parse_options($str);
129
130           ### $options would contain: ###
131           $options = {
132                       'foo'       => 0,
133                       'bar'       => 0,
134                       'one-dash'  => 1,
135                       'baz'       => 1,
136                       'quux'      => 'bleh',
137                       'single'    => 'blah\'',
138                       'option'    => 'some\'thing'
139           };
140
141           ### and this is the munged version of the input string,
142           ### ie what's left of the input minus the options
143           $munged = 'command arg';
144
145       As you can see, you can either use a single or a double "-" to indicate
146       an option.  If you prefix an option with "no-" and do not give it a
147       value, it will be set to 0.  If it has no prefix and no value, it will
148       be set to 1.  Otherwise, it will be set to its value. Note also that it
149       can deal fine with single/double quoting issues.
150
151   $str = $term->history_as_string
152       Convenience wrapper around "Term::UI::History->history_as_string".
153
154       Consult the "Term::UI::History" man page for details.
155

GLOBAL VARIABLES

157       The behaviour of Term::UI can be altered by changing the following
158       global variables:
159
160   $Term::UI::VERBOSE
161       This controls whether Term::UI will issue warnings and explanations as
162       to why certain things may have failed. If you set it to 0, Term::UI
163       will not output any warnings.  The default is 1;
164
165   $Term::UI::AUTOREPLY
166       This will make every question be answered by the default, and warn if
167       there was no default provided. This is particularly useful if your
168       program is run in non-interactive mode.  The default is 0;
169
170   $Term::UI::INVALID
171       This holds the string that will be printed when the user makes an
172       invalid choice.  You can override this string from your program if you,
173       for example, wish to do localization.  The default is "Invalid
174       selection, please try again: "
175
176   $Term::UI::History::HISTORY_FH
177       This is the filehandle all the print statements from this module are
178       being sent to. Please consult the "Term::UI::History" manpage for
179       details.
180
181       This defaults to *STDOUT.
182

EXAMPLES

184   Basic get_reply sample
185           ### ask a user (with an open question) for their favourite colour
186           $reply = $term->get_reply( prompt => 'Your favourite colour? );
187
188       which would look like:
189
190           Your favourite colour?
191
192       and $reply would hold the text the user typed.
193
194   get_reply with choices
195           ### now provide a list of choices, so the user has to pick one
196           $reply = $term->get_reply(
197                       prompt  => 'Your favourite colour?',
198                       choices => [qw|red green blue|] );
199
200       which would look like:
201
202             1> red
203             2> green
204             3> blue
205
206           Your favourite colour?
207
208       $reply will hold one of the choices presented. "Term::UI" will repose
209       the question if the user attempts to enter an answer that's not in the
210       list of choices. The string presented is held in the $Term::UI::INVALID
211       variable (see the "GLOBAL VARIABLES" section for details.
212
213   get_reply with choices and default
214           ### provide a sensible default option -- everyone loves blue!
215           $reply = $term->get_reply(
216                       prompt  => 'Your favourite colour?',
217                       choices => [qw|red green blue|],
218                       default => 'blue' );
219
220       which would look like:
221
222             1> red
223             2> green
224             3> blue
225
226           Your favourite colour? [3]:
227
228       Note the default answer after the prompt. A user can now just hit
229       "enter" (or set $Term::UI::AUTOREPLY -- see the "GLOBAL VARIABLES"
230       section) and the sensible answer 'blue' will be returned.
231
232   get_reply using print_me & multi
233           ### allow the user to pick more than one colour and add an
234           ### introduction text
235           @reply = $term->get_reply(
236                       print_me    => 'Tell us what colours you like',
237                       prompt      => 'Your favourite colours?',
238                       choices     => [qw|red green blue|],
239                       multi       => 1 );
240
241       which would look like:
242
243           Tell us what colours you like
244             1> red
245             2> green
246             3> blue
247
248           Your favourite colours?
249
250       An answer of "3 2 1" would fill @reply with "blue green red"
251
252   get_reply & allow
253           ### pose an open question, but do a custom verification on
254           ### the answer, which will only exit the question loop, if
255           ### the answer matches the allow handler.
256           $reply = $term->get_reply(
257                       prompt  => "What is the magic number?",
258                       allow   => 42 );
259
260       Unless the user now enters 42, the question will be reposed over and
261       over again. You can use more sophisticated "allow" handlers (even
262       subroutines can be used). The "allow" handler is implemented using
263       "Params::Check"'s "allow" function. Check its manpage for details.
264
265   an elaborate ask_yn sample
266           ### ask a user if he likes cookies. Default to a sensible 'yes'
267           ### and inform him first what cookies are.
268           $bool = $term->ask_yn( prompt   => 'Do you like cookies?',
269                                  default  => 'y',
270                                  print_me => 'Cookies are LOVELY!!!' );
271
272       would print:
273
274           Cookies are LOVELY!!!
275           Do you like cookies? [Y/n]:
276
277       If a user then simply hits "enter", agreeing with the default, $bool
278       would be set to "true". (Simply hitting 'y' would also return "true".
279       Hitting 'n' would return "false")
280
281       We could later retrieve this interaction by printing out the Q&A
282       history as follows:
283
284           print $term->history_as_string;
285
286       which would then print:
287
288           Cookies are LOVELY!!!
289           Do you like cookies? [Y/n]:  y
290
291       There's a chance we're doing this non-interactively, because a console
292       is missing, the user indicated he just wanted the defaults, etc.
293
294       In this case, simply setting $Term::UI::AUTOREPLY to true, will return
295       from every question with the default answer set for the question.  Do
296       note that if "AUTOREPLY" is true, and no default is set, "Term::UI"
297       will warn about this and return "undef".
298

See Also

300       "Params::Check", "Term::ReadLine", "Term::UI::History"
301

BUG REPORTS

303       Please report bugs or other issues to <bug-term-ui@rt.cpan.org<gt>.
304

AUTHOR

306       This module by Jos Boumans <kane@cpan.org>.
307
309       This library is free software; you may redistribute and/or modify it
310       under the same terms as Perl itself.
311
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314perl v5.34.0                      2022-01-21                       Term::UI(3)
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