1Term::ShellUI(3) User Contributed Perl Documentation Term::ShellUI(3)
2
6 Term::ShellUI - A fully-featured shell-like command line environment
7
9 use Term::ShellUI;
10 my $term = new Term::ShellUI(
11 commands => {
12 "cd" => {
13 desc => "Change to directory DIR",
14 maxargs => 1, args => sub { shift->complete_onlydirs(@_); },
15 proc => sub { chdir($_[0] || $ENV{HOME} || $ENV{LOGDIR}); },
16 },
17 "chdir" => { alias => 'cd' },
18 "pwd" => {
19 desc => "Print the current working directory",
20 maxargs => 0, proc => sub { system('pwd'); },
21 },
22 "quit" => {
23 desc => "Quit this program", maxargs => 0,
24 method => sub { shift->exit_requested(1); },
25 }},
26 history_file => '~/.shellui-synopsis-history',
27 );
28 print 'Using '.$term->{term}->ReadLine."\n";
29 $term->run();
30
32 Term::ShellUI uses the history and autocompletion features of
33 Term::ReadLine to present a sophisticated command-line interface to the
34 user. It tries to make every feature that one would expect to see in a
35 fully interactive shell trivial to implement. You simply declare your
36 command set and let ShellUI take care of the heavy lifting.
37 This module was previously called Term::GDBUI.
39
41 A command set is the data structure that describes your application's
42 entire user interface. It's easiest to illustrate with a working
43 example. We shall implement the following 6 "COMMAND"s:
44 help
46 Prints the help for the given command. With no arguments, prints a
47 list and short summary of all available commands.
48 h This is just a synonym for "help". We don't want to list it in the
50 possible completions. Of course, pressing "h<tab><return>" will
51 autocomplete to "help" and then execute the help command.
52 Including this command allows you to simply type "h<return>".
53 The 'alias' directive used to be called 'syn' (for synonym).
55 Either term works.
56 exists
58 This command shows how to use the "complete_files" routines to
59 complete on file names, and how to provide more comprehensive help.
60 show
62 Demonstrates subcommands (like GDB's show command). This makes it
63 easy to implement commands like "show warranty" and "show args".
64 show args
66 This shows more advanced argument processing. First, it uses cusom
67 argument completion: a static completion for the first argument
68 (either "create" or "delete") and the standard file completion for
69 the second. When executed, it echoes its own command name followed
70 by its arguments.
71 quit
73 How to nicely quit. Term::ShellUI also follows Term::ReadLine's
74 default of quitting when Control-D is pressed.
75 This code is fairly comprehensive because it attempts to demonstrate
77 most of Term::ShellUI's many features. You can find a working version
78 of this exact code titled "synopsis" in the examples directory. For a
79 more real-world example, see the fileman-example in the same directory.
80 sub get_commands
82 {
83 return {
84 "help" => {
85 desc => "Print helpful information",
86 args => sub { shift->help_args(undef, @_); },
87 method => sub { shift->help_call(undef, @_); }
88 },
89 "h" => { alias => "help", exclude_from_completion=>1},
90 "exists" => {
91 desc => "List whether files exist",
92 args => sub { shift->complete_files(@_); },
93 proc => sub {
94 print "exists: " .
95 join(", ", map {-e($_) ? "<$_>":$_} @_) .
96 "\n";
97 },
98 doc => <<EOL,
99 Comprehensive documentation for our ls command.
100 If a file exists, it is printed in <angle brackets>.
101 The help can\nspan\nmany\nlines
102 EOL
103 },
104 "show" => {
105 desc => "An example of using subcommands",
106 cmds => {
107 "warranty" => { proc => "You have no warranty!\n" },
108 "args" => {
109 minargs => 2, maxargs => 2,
110 args => [ sub {qw(create delete)},
111 \&Term::ShellUI::complete_files ],
112 desc => "Demonstrate method calling",
113 method => sub {
114 my $self = shift;
115 my $parms = shift;
116 print $self->get_cname($parms->{cname}) .
117 ": " . join(" ",@_), "\n";
118 },
119 },
120 },
121 },
122 "quit" => {
123 desc => "Quit using Fileman",
124 maxargs => 0,
125 method => sub { shift->exit_requested(1); }
126 },
127 "q" => { alias => 'quit', exclude_from_completion => 1 },
128 };
129 }
130
132 This data structure describes a single command implemented by your
133 application. "help", "exit", etc. All fields are optional. Commands
134 are passed to Term::ShellUI using a "COMMAND SET".
135 desc
137 A short, one-line description for the command. Normally this is a
138 simple string, but it may also be a subroutine that will be called
139 every time the description is printed. The subroutine takes two
140 arguments, $self (the Term::ShellUI object), and $cmd (the command
141 hash for the command), and returns the command's description as a
142 string.
143 doc A comprehensive, many-line description for the command. Like desc,
145 this is normally a string but if you store a reference to a
146 subroutine in this field, it will be called to calculate the
147 documentation. Your subroutine should accept three arguments: self
148 (the Term::ShellUI object), cmd (the command hash for the command),
149 and the command's name. It should return a string containing the
150 command's documentation. See examples/xmlexer to see how to read
151 the doc for a command out of the pod.
152 minargs
154 maxargs
155 These set the minimum and maximum number of arguments that this
156 command will accept.
157 proc
159 This contains a reference to the subroutine that should be executed
160 when this command is called. Arguments are those passed on the
161 command line and the return value is the value returned by call_cmd
162 and process_a_cmd (i.e. it is ignored unless your application makes
163 use of it).
164 If this field is a string instead of a subroutine ref, the string
166 is printed when the command is executed (good for things like "Not
167 implemented yet"). Examples of both subroutine and string procs
168 can be seen in the example above.
169 method
171 Similar to proc, but passes more arguments. Where proc simply
172 passes the arguments for the command, method also passes the
173 Term::ShellUI object and the command's parms object (see "call_cmd"
174 for more on parms). Most commands can be implemented entirely
175 using a simple proc procedure, but sometimes they require addtional
176 information supplied to the method. Like proc, method may also be
177 a string.
178 args
180 This tells how to complete the command's arguments. It is usually
181 a subroutine. See "complete_files" for an reasonably simple
182 example, and the "complete" routine for a description of the
183 arguments and cmpl data structure.
184 Args can also be an arrayref. Each position in the array will be
186 used as the corresponding argument. See "show args" in
187 get_commands above for an example. The last argument is repeated
188 indefinitely (see "maxargs" for how to limit this).
189 Finally, args can also be a string. The string is intended to be a
191 reminder and is printed whenever the user types tab twice (i.e. "a
192 number between 0 and 65536"). It does not affect completion at
193 all.
194 cmds
196 Command sets can be recursive. This allows a command to have
197 subcommands (like GDB's info and show commands, and the show
198 command in the example above). A command that has subcommands
199 should only have two fields: cmds (of course), and desc (briefly
200 describe this collection of subcommands). It may also implement
201 doc, but ShellUI's default behavior of printing a summary of the
202 command's subcommands is usually sufficient. Any other fields
203 (args, method, maxargs, etc) will be taken from the subcommand.
204 exclude_from_completion
206 If this field exists, then the command will be excluded from
207 command-line completion. This is useful for one-letter
208 abbreviations, such as "h"->"help": including "h" in the
209 completions just clutters up the screen.
210 exclude_from_history
212 If this field exists, the command will never be stored in history.
213 This is useful for commands like help and quit.
214 Default Command
216 If your command set includes a command named '' (the empty string),
217 this pseudo-command will be called any time the actual command cannot
218 be found. Here's an example:
219 '' => {
221 proc => "HA ha. No command here by that name\n",
222 desc => "HA ha. No help for unknown commands.",
223 doc => "Yet more taunting...\n",
224 },
225 Note that minargs and maxargs for the default command are ignored.
227 method and proc will be called no matter how many arguments the user
228 entered.
229
231 Normally, when the user types 'help', she receives a short summary of
232 all the commands in the command set. However, if your application has
233 30 or more commands, this can result in information overload. To
234 manage this, you can organize your commands into help categories
235 All help categories are assembled into a hash and passed to the the
237 default help_call and "help_args" methods. If you don't want to use
238 help categories, simply pass undef for the categories.
239 Here is an example of how to declare a collection of help categories:
241 my $helpcats = {
243 breakpoints => {
244 desc => "Commands to halt the program",
245 cmds => qw(break tbreak delete disable enable),
246 },
247 data => {
248 desc => "Commands to examine data",
249 cmds => ['info', 'show warranty', 'show args'],
250 }
251 };
252 "show warranty" and "show args" on the last line above are examples of
254 how to include subcommands in a help category: separate the command and
255 subcommands with whitespace.
256
258 Callbacks are functions supplied by ShellUI but intended to be called
259 by your application. They implement common functions like 'help' and
260 'history'.
261 help_call(cats, parms, topic)
263 Call this routine to implement your help routine. Pass the help
264 categories or undef, followed by the command-line arguments:
265 "help" => { desc => "Print helpful information",
267 args => sub { shift->help_args($helpcats, @_); },
268 method => sub { shift->help_call($helpcats, @_); } },
269 help_args
271 This provides argument completion for help commands. See the
272 example above for how to call it.
273 complete_files
275 Completes on filesystem objects (files, directories, etc). Use
276 either
277 args => sub { shift->complete_files(@_) },
279 or
281 args => \&complete_files,
283 Starts in the current directory.
285 complete_onlyfiles
287 Like "complete_files"" but excludes directories, device nodes, etc.
288 It returns regular files only.
289 complete_onlydirs
291 Like "complete_files"", but excludes files, device nodes, etc. It
292 returns only directories. It does return the . and .. special
293 directories so you'll need to remove those manually if you don't
294 want to see them:
295 args = sub { grep { !/^\.?\.$/ } complete_onlydirs(@_) },
297 history_call
299 You can use this callback to implement the standard bash history
300 command. This command supports:
301 NUM display last N history items
303 (displays all history if N is omitted)
304 -c clear all history
305 -d NUM delete an item from the history
306 Add it to your command set using something like this:
308 "history" => { desc => "Prints the command history",
310 doc => "Specify a number to list the last N lines of history" .
311 "Pass -c to clear the command history, " .
312 "-d NUM to delete a single item\n",
313 args => "[-c] [-d] [number]",
314 method => sub { shift->history_call(@_) },
315 },
316
318 These are the routines that your application calls to create and use a
319 Term::ShellUI object. Usually you simply call new() and then run() --
320 everything else is handled automatically. You only need to read this
321 section if you wanted to do something out of the ordinary.
322 new Term::ShellUI("named args...")
324 Creates a new ShellUI object.
325 It accepts the following named parameters:
327 app
329 The name of this application (will be passed to "new" in
330 Term::ReadLine). Defaults to $0, the name of the current
331 executable.
332 term
334 Usually Term::ShellUI uses its own Term::ReadLine object
335 (created with "new Term::ReadLine $args{'app'}"). However, if
336 you can create a new Term::ReadLine object yourself and supply
337 it using the term argument.
338 blank_repeats_cmd
340 This tells Term::ShellUI what to do when the user enters a blank
341 line. Pass 0 (the default) to have it do nothing (like Bash),
342 or 1 to have it repeat the last command (like GDB).
343 commands
345 A hashref containing all the commands that ShellUI will respond
346 to. The format of this data structure can be found below in the
347 command set documentation. If you do not supply any commands to
348 the constructor, you must call the "commands" method to provide
349 at least a minimal command set before using many of the
350 following calls. You may add or delete commands or even change
351 the entire command set at any time.
352 history_file
354 If defined then the command history is saved to this file on
355 exit. It should probably specify a dotfile in the user's home
356 directory. Tilde expansion is performed, so something like
357 "~/.myprog-history" is perfectly acceptable.
358 history_max = 500
360 This tells how many items to save to the history file. The
361 default is 500.
362 Note that this parameter does not affect in-memory history.
364 Term::ShellUI makes no attemt to cull history so you're at the
365 mercy of the default of whatever ReadLine library you are using.
366 See "StifleHistory" in Term::ReadLine::Gnu for one way to change
367 this.
368 keep_quotes
370 Normally all unescaped, unnecessary quote marks are stripped.
371 If you specify "keep_quotes=>1", however, they are preserved.
372 This is useful if your application uses quotes to delimit, say,
373 Perl-style strings.
374 backslash_continues_command
376 Normally commands don't respect backslash continuation. If you
377 pass backslash_continues_command=>1 to "new", then whenever a
378 line ends with a backslash, Term::ShellUI will continue reading.
379 The backslash is replaced with a space, so
380 $ abc \
381 > def
382 Will produce the command string 'abc def'.
384 prompt
386 This is the prompt that should be displayed for every request.
387 It can be changed at any time using the "prompt" method. The
388 default is <"$0 ">> (see app above).
389 If you specify a code reference, then the coderef is executed
391 and its return value is set as the prompt. Two arguments are
392 passed to the coderef: the Term::ShellUI object, and the raw
393 command. The raw command is always "" unless you're using
394 command completion, where the raw command is the command line
395 entered so far.
396 For example, the following line sets the prompt to "## > " where
398 ## is the current number of history items.
399 $term->prompt(sub { $term->{term}->GetHistory() . " > " });
401 If you specify an arrayref, then the first item is the normal
403 prompt and the second item is the prompt when the command is
404 being continued. For instance, this would emulate Bash's
405 behavior ($ is the normal prompt, but > is the prompt when
406 continuing).
407 $term->prompt(['$', '>']);
409 Of course, you specify backslash_continues_command=>1 to to
411 "new" to cause commands to continue.
412 And, of course, you can use an array of procs too.
414 $term->prompt([sub {'$'}, sub {'<'}]);
416 token_chars
418 This argument specifies the characters that should be considered
419 tokens all by themselves. For instance, if I pass
420 token_chars=>'=', then 'ab=123' would be parsed to ('ab', '=',
421 '123'). Without token_chars, 'ab=123' remains a single string.
422 NOTE: you cannot change token_chars after the constructor has
424 been called! The regexps that use it are compiled once (m//o).
425 display_summary_in_help
427 Usually it's easier to have the command's summary (desc) printed
428 first, then follow it with the documentation (doc). However, if
429 the doc already contains its description (for instance, if
430 you're reading it from a podfile), you don't want the summary up
431 there too. Pass 0 to prevent printing the desc above the doc.
432 Defaults to 1.
433 process_a_cmd([cmd])
435 Runs the specified command or prompts for it if no arguments are
436 supplied. Returns the result or undef if no command was called.
437 run()
439 The main loop. Processes all commands until someone calls
440 "/"exit_requested(exitflag)"(true)".
441 If you pass arguments, they are joined and run once. For instance,
443 $term->run(@ARGV) allows your program to be run interactively or
444 noninteractively:
445 myshell help
447 Runs the help command and exits.
448 myshell
450 Invokes an interactive Term::ShellUI.
451 prompt(newprompt)
453 If supplied with an argument, this method sets the command-line
454 prompt. Returns the old prompt.
455 commands(newcmds)
457 If supplied with an argument, it sets the current command set.
458 This can be used to change the command set at any time. Returns
459 the old command set.
460 add_commands(newcmds)
462 Takes a command set as its first argument. Adds all the commands
463 in it the current command set. It silently replaces any commands
464 that have the same name.
465 exit_requested(exitflag)
467 If supplied with an argument, sets Term::ShellUI's finished flag to
468 the argument (1=exit, 0=don't exit). So, to get the interpreter to
469 exit at the end of processing the current command, call
470 "$self->exit_requested(1)". To cancel an exit request before the
471 command is finished, "$self->exit_requested(0)". Returns the old
472 state of the flag.
473 add_eof_exit_hook(subroutine_reference)
475 Call this method to add a subroutine as a hook into Term::ShellUI's
476 "exit on EOF" (Ctrl-D) functionality. When a user enters Ctrl-D,
477 Term::ShellUI will call each function in this hook list, in order,
478 and will exit only if all of them return 0. The first function to
479 return a non-zero value will stop further processing of these hooks
480 and prevent the program from exiting.
481 The return value of this method is the placement of the hook
483 routine in the hook list (1 is first) or 0 (zero) on failure.
484 get_cname(cname)
486 This is a tiny utility function that turns the cname (array ref of
487 names for this command as returned by "get_deep_command") into a
488 human-readable string. This function exists only to ensure that we
489 do this consistently.
490
492 These are routines that probably already do the right thing. If not,
493 however, they are designed to be overridden.
494 blank_line()
496 This routine is called when the user inputs a blank line. It
497 returns a string specifying the command to run or undef if nothing
498 should happen.
499 By default, ShellUI simply presents another command line. Pass
501 "blank_repeats_cmd=>1" to the constructor to get ShellUI to repeat
502 the previous command. Override this method to supply your own
503 behavior.
504 error(msg)
506 Called when an error occurrs. By default, the routine simply
507 prints the msg to stderr. Override it to change this behavior. It
508 takes any number of arguments, cocatenates them together and prints
509 them to stderr.
510
512 Term::ReadLine makes writing a completion routine a notoriously
513 difficult task. Term::ShellUI goes out of its way to make it as easy
514 as possible. The best way to write a completion routine is to start
515 with one that already does something similar to what you want (see the
516 "CALLBACKS" section for the completion routines that come with
517 ShellUI).
518 Your routine returns an arrayref of possible completions, a string
520 conaining a short but helpful note, or undef if an error prevented any
521 completions from being generated. Return an empty array if there are
522 simply no applicable competions. Be careful; the distinction between
523 no completions and an error can be significant.
524 Your routine takes two arguments: a reference to the ShellUI object and
526 cmpl, a data structure that contains all the information you need to
527 calculate the completions. Set $term->{debug_complete}=5 to see the
528 contents of cmpl:
529 str
531 The exact string that needs completion. Often, for simple
532 completions, you don't need anything more than this.
533 NOTE: str does not respect token_chars! It is supplied unchanged
535 from Readline and so uses whatever tokenizing it implements.
536 Unfortunately, if you've changed token_chars, this will often be
537 different from how Term::ShellUI would tokenize the same string.
538 cset
540 Command set for the deepest command found (see "get_deep_command").
541 If no command was found then cset is set to the topmost command set
542 ($self->commands()).
543 cmd
545 The command hash for deepest command found or undef if no command
546 was found (see "get_deep_command"). cset is the command set that
547 contains cmd.
548 cname
550 The full name of deepest command found as an array of tokens (see
551 "get_deep_command"). Use "get_cname" to convert this into a human-
552 readable string.
553 args
555 The arguments (as a list of tokens) that should be passed to the
556 command (see "get_deep_command"). Valid only if cmd is non-null.
557 Undef if no args were passed.
558 argno
560 The index of the argument (in args) containing the cursor. If the
561 user is trying to complete on the command name, then argno is
562 negative (because the cursor comes before the arguments).
563 tokens
565 The tokenized command-line.
566 tokno
568 The index of the token containing the cursor.
569 tokoff
571 The character offset of the cursor in the token.
572 For instance, if the cursor is on the first character of the third
574 token, tokno will be 2 and tokoff will be 0.
575 twice
577 True if user has hit tab twice in a row. This usually means that
578 you should print a message explaining the possible completions.
579 If you return your completions as a list, then $twice is handled for
581 you automatically. You could use it, for instance, to display an
582 error message (using completemsg) telling why no completions could
583 be found.
584 rawline
586 The command line as a string, exactly as entered by the user.
587 rawstart
589 The character position of the cursor in rawline.
590 The following are utility routines that your completion function can
592 call.
593 completemsg(msg)
595 Allows your completion routine to print to the screen while
596 completing (i.e. to offer suggestions or print debugging info --
597 see debug_complete). If it just blindly calls print, the prompt
598 will be corrupted and things will be confusing until the user
599 redraws the screen (probably by hitting Control-L).
600 $self->completemsg("You cannot complete here!\n");
602 Note that Term::ReadLine::Perl doesn't support this so the user
604 will always have to hit Control-L after printing. If your
605 completion routine returns a string rather than calling
606 completemsg() then it should work everywhere.
607 suppress_completion_append_character()
609 When the ReadLine library finds a unique match among the list that
610 you returned, it automatically appends a space. Normally this is
611 what you want (i.e. when completing a command name, in help, etc.)
612 However, if you're navigating the filesystem, this is definitely
613 not desirable (picture having to hit backspace after completing
614 each directory).
615 Your completion function needs to call this routine every time it
617 runs if it doesn't want a space automatically appended to the
618 completions that it returns.
619 suppress_completion_escape()
621 Normally everything returned by your completion routine is escaped
622 so that it doesn't get destroyed by shell metacharacter
623 interpretation (quotes, backslashes, etc). To avoid escaping twice
624 (disastrous), a completion routine that does its own escaping
625 (perhaps using Text::Shellwords::Cursorparse_escape) must call
626 suppress_completion_escape every time is called.
627 force_to_string(cmpl, commmpletions, default_quote)
629 If all the completions returned by your completion routine should
630 be enclosed in single or double quotes, call force_to_string on
631 them. You will most likely need this routine if keep_quotes is 1.
632 This is useful when completing a construct that you know must
633 always be quoted.
634 force_to_string surrounds all completions with the quotes supplied
636 by the user or, if the user didn't supply any quotes, the quote
637 passed in default_quote. If the programmer didn't supply a
638 default_quote and the user didn't start the token with an open
639 quote, then force_to_string won't change anything.
640 Here's how to use it to force strings on two possible completions,
642 aaa and bbb. If the user doesn't supply any quotes, the
643 completions will be surrounded by double quotes.
644 args => sub { shift->force_to_string(@_,['aaa','bbb'],'"') },
646 Calling force_to_string escapes your completions (unless your
648 callback calls suppress_completion_escape itself), then calls
649 suppress_completion_escape to ensure the final quote isn't mangled.
650
652 These commands are internal to ShellUI. They are documented here only
653 for completeness -- you should never need to call them.
654 get_deep_command
656 Looks up the supplied command line in a command hash. Follows all
657 synonyms and subcommands. Returns undef if the command could not
658 be found.
659 my($cset, $cmd, $cname, $args) =
661 $self->get_deep_command($self->commands(), $tokens);
662 This call takes two arguments:
664 cset
666 This is the command set to use. Pass $self->commands() unless
667 you know exactly what you're doing.
668 tokens
670 This is the command line that the command should be read from.
671 It is a reference to an array that has already been split on
672 whitespace using Text::Shellwords::Cursor::parse_line.
673 and it returns a list of 4 values:
675 1. cset: the deepest command set found. Always returned.
677 2. cmd: the command hash for the command. Undef if no command was
679 found.
680 3. cname: the full name of the command. This is an array of
682 tokens, i.e. ('show', 'info'). Returns as deep as it could find
683 commands even if the final command was not found.
684 4. args: the command's arguments (all remaining tokens after the
686 command is found).
687 get_cset_completions(cset)
689 Returns a list of commands from the passed command set that are
690 suitable for completing.
691 call_args
693 Given a command set, does the correct thing at this stage in the
694 completion (a surprisingly nontrivial task thanks to ShellUI's
695 flexibility). Called by complete().
696 complete
698 This routine figures out the command set of the completion routine
699 that needs to be called, then calls call_args(). It is called by
700 completion_function.
701 You should override this routine if your application has custom
703 completion needs (like non-trivial tokenizing, where you'll need to
704 modify the cmpl data structure). If you override this routine, you
705 will probably need to override call_cmd as well.
706 completion_function
708 This is the entrypoint to the ReadLine completion callback. It
709 sets up a bunch of data, then calls complete to calculate the
710 actual completion.
711 To watch and debug the completion process, you can set
713 $self->{debug_complete} to 2 (print tokenizing), 3 (print
714 tokenizing and results) or 4 (print everything including the cmpl
715 data structure).
716 Youu should never need to call or override this function. If you
718 do (but, trust me, you don't), set
719 $self->{term}->Attribs->{completion_function} to point to your own
720 routine.
721 See the Term::ReadLine documentation for a description of the
723 arguments.
724 get_cmd_summary(tokens, cset)
726 Prints a one-line summary for the given command. Uses
727 self->commands() if cset is not specified.
728 get_cmd_help(tokens, cset)
730 Prints the full help text for the given command. Uses
731 self->commands() if cset is not specified.
732 get_category_summary(name, cats)
734 Prints a one-line summary for the named category in the category
735 hash specified in cats.
736 get_category_help(cat, cset)
738 Returns a summary of the commands listed in cat. You must pass the
739 command set that contains those commands in cset.
740 get_all_cmd_summaries(cset)
742 Pass it a command set, and it will return a string containing the
743 summaries for each command in the set.
744 load_history()
746 If $self->{history_file} is set (see "new"), this will load all
747 history from that file. Called by run on startup. If you don't
748 use run, you will need to call this command manually.
749 save_history()
751 If $self->{history_file} is set (see "new"), this will save all
752 history to that file. Called by run on shutdown. If you don't use
753 run, you will need to call this command manually.
754 The history routines don't use ReadHistory and WriteHistory so they
756 can be used even if other ReadLine libs are being used.
757 save_history requires that the ReadLine lib supply a GetHistory
758 call.
759 call_command(parms)
761 Executes a command and returns the result. It takes a single
762 argument: the parms data structure.
763 parms is a subset of the cmpl data structure (see the
765 "complete(cmpl)" in complete routine for more). Briefly, it
766 contains: cset, cmd, cname, args (see "get_deep_command"), tokens
767 and rawline (the tokenized and untokenized command lines). See
768 complete for full descriptions of these fields.
769 This call should be overridden if you have exotic command
771 processing needs. If you override this routine, you will probably
772 need to override the complete routine too.
773
775 Copyright (c) 2003-2011 Scott Bronson, all rights reserved. This
776 program is free software released under the MIT license.
777
779 Scott Bronson <bronson@rinspin.com> Lester Hightower
780 <hightowe@cpan.org> Ryan Gies <ryan@livesite.net> Martin Kluge
781 <mk@elxsi.de>
782
784 Hey! The above document had some coding errors, which are explained
785 below:
786 Around line 866:
788 alternative text '/"exit_requested(exitflag)"' contains non-escaped
789 | or /
790perl v5.30.0 2019-07-26 Term::ShellUI(3)