NAME
Term::TUI - simple tool for building text-based user interfaces
SYNOPSIS
If TUI_Run is the only routine being used:
use Term::TUI;
$flag=TUI_Run($command,\%desc);
$version=Term::TUI::TUI_Version;
If other TUI subroutines are used:
use Term::TUI qw(:all);
$flag=TUI_Run($command,\%desc);
TUI_Out($message);
$flag=TUI_Script(\%desc,$script,$sep);
DESCRIPTION
Many times, I've wanted to quickly write a nice text-based user
interface around a set of perl routines only to end up writing the full
(though simple) parser and interface to make it nice enough, and
friendly enough, to be usable.
This module creates a simple but powerful text based user interface
around perl routines, adding such features as command line history,
command line editing, online help, and command completion, while hiding
all details of the interface from the programmer.
The interface is described in a simple hash which is passed to the
TUI_Run command. This routine exits only when the user has exited the
program (returning a flag signalling any special exit conditions).
ROUTINES
TUI_Run
use Term::TUI;
$flag=TUI_Run($command,\%desc);
The TUI_Run command is used to run the interface. It prompts the
user for commands and executes them (based on description of passed
in as %desc) until the user exits. The return flag is 0 unless the
user exited with the Abort command when it is 1.
TUI_Script
use Term::TUI qw(:all);
$flag=TUI_Script(\%desc,$script [,$sep]);
This allows you to pass in commands in a "script" instead of an
interactive session. The script is a series of commands separated by
a semicolon (or the string included in $sep).
TUI_Version
use Term::TUI qw(:all);
$vers=TUI_Version;
Returns the version of the module.
TUI_Out
use Term::TUI qw(:all);
TUI_Out($mess);
This is used in the routines given in the description hash to send a
message to STDOUT.
INTERFACE DESCRIPTION
The interface allows you to describe multiple "modes" organized in a
simple tree-like hierarchy (or modes, submodes, subsubmodes, etc.), each
of which has it's own set of commands specific to that mode. I've
modeled it after a unix filesystem with directories being "modes" and
executables being equivalent to commands. So, you might want to model
the following tree:
/
+--------------------+
math string
| |
+-----+-----+ +------+
hex add* mult* len* subs*
|
+-----+
add* mult*
Here the "executables" are marked with asterixes(*). So in math mode,
you could type "add" or "mult" to add a list of numbers together or
multiply them together. It also has a submode "hex" where you can do
that in hexidecimal.
I find this type of interface very conveniant in many cases, but a
nuisance to write. This module handles this trivially. The above
interface can be written with the following 2 perl commands:
%modes =
(".HELP" => "This is the main help.\nNot a lot of info here.",
"math" => {".HELP" => "A simple calculator. Currently it can\n" .
"only add and multiply in hex or decimal.",
"add" => [ "Add numbers together." , Add,0 ],
"mult" => [ "Multiply numbers together.", Mult,0 ],
"hex" => {".HELP" => "Math in hex.",
"add" => [ "Add hex numbers together.",
Add,1 ],
"mult" => [ "Multiply hex numbers together.",
Mult,1 ]
}
},
"string" => {".HELP" => "String operations",
"subs" => [ "Take STRING,POS,LEN and returns substring.",
Substring ],
"len" => [ "Returns the length of a string.",
Length ]
}
);
$flag=TUI_Run("sample",\%modes);
print "*** ABORT ***\n" if ($flag);
You also have to write an Add, Mult, Substring, and Length subroutine of
course, but once that's done, you end up with a rather nice text based
user interface. The following are excerpts from a session using the
sample interface defined above:
Changing modes is trivial. Just type in the new mode using a syntax
similar to the unix filesystem:
sample> string
sample:string> /math/hex
sample:math/hex> ..
sample:math> hex
sample:math/hex> /
sample>
When in a given mode, you can just type commands relevant to that mode:
sample:string> subs barnyard 1 3
Substring = arn
sample:string> len barnyard
Length = 8
You can also explicitely type in the mode for a command. In this
situation, commands can be typed as MODE/CMD ARGS or MODE CMD ARGS
equivalently:
sample:string> /math/hex/add 4 6 1
Total = b
sample:string> /math mult 4 6 2
Total = 48
There are several built-in commands including "..", "/", "help",
"abort", "exit", and "quit". The last two ("exit" and "quit") are
equivalent and mean to exit and return 0. "abort" exits with a value of
1.
There is also online help:
sample> help
This is the main help.
Not a lot of info here.
Additional help:
Modes: math string
Cmds : .. / abort exit help quit
sample> help /string
String operations
Additional help:
Cmds : .. / abort exit help quit
len subs
sample> math
sample:math> help
A simple calculator. Currently it can only
add and multiply in hex or decimal.
Additional help:
Modes: hex
Cmds : .. / abort exit help quit
add mult
sample:math> help add
Add numbers together.
sample:math> help /string len
Returns the length of a string.
sample:math> help /string/subs
Take STRING,POS,LEN and returns a substring.
Currently, Term::TUI does not have much in the way of bells and
whistles, and I doubt it ever will. It's not designed for a full-blown,
feature-rich user interface. It's mainly intended for simple control or
config tools (similar to lpc for example) used primarily by the sysadmin
type people (who else is interested in a text-based interface after all
:-).
There is also a non-interactive form which allows the same interface to
be called in scripts.
TUI_Script(\%modes,"/math add 3 5; string; subs barnyard 1 3");
returns
Total = 8
Substring = arn
TUI DOES use one of the Term::ReadLine modules for the interactive
session, so if you have Term::ReadLine::GNU or Term::ReadLine::Perl
installed, you can use things like command history and command line
editing.
KNOWN PROBLEMS
None known at this point.
LICENSE
This script is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
AUTHOR
Sullivan Beck (sbeck@cpan.org)