Term::ReadLine(3) Term::ReadLine(3)
NAME
Term::ReadLine - Perl interface to various readline packages. If no real
package is found, substitutes stubs instead of basic functions.
SYNOPSIS
use Term::ReadLine;
$term = new Term::ReadLine 'Simple Perl calc';
$prompt = "Enter your arithmetic expression: ";
$OUT = $term->OUT || STDOUT;
while ( defined ($_ = $term->readline($prompt)) ) {
$res = eval($_), "\n";
warn $@ if $@;
print $OUT $res, "\n" unless $@;
$term->addhistory($_) if /\S/;
}
DESCRIPTION
This package is just a front end to some other packages. At the moment
this description is written, the only such package is Term-ReadLine,
available on CPAN near you. The real target of this stub package is to
set up a common interface to whatever Readline emerges with time.
Minimal set of supported functions
All the supported functions should be called as methods, i.e., either as
$term = new Term::ReadLine 'name';
or as
$term->addhistory('row');
where $term is a return value of Term::ReadLine->Init.
ReadLine returns the actual package that executes the commands. Among
possible values are Term::ReadLine::Gnu,
Term::ReadLine::Perl, Term::ReadLine::Stub Exporter.
new returns the handle for subsequent calls to following
functions. Argument is the name of the application.
Optionally can be followed by two arguments for IN and OUT
filehandles. These arguments should be globs.
readline gets an input line, possibly with actual readline support.
Trailing newline is removed. Returns undef on EOF.
addhistory adds the line to the history of input, from where it can be
used if the actual readline is present.
IN, $OUT return the filehandles for input and output or undef if
readline input and output cannot be used for Perl.
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Term::ReadLine(3) Term::ReadLine(3)
MinLine If argument is specified, it is an advice on minimal size of
line to be included into history. undef means do not include
anything into history. Returns the old value.
findConsole returns an array with two strings that give most appropriate
names for files for input and output using conventions
"<$in", ">out".
Attribs returns a reference to a hash which describes internal
configuration of the package. Names of keys in this hash
conform to standard conventions with the leading rl_
stripped.
Features Returns a reference to a hash with keys being features
present in current implementation. Several optional features
are used in the minimal interface: appname should be present
if the first argument to new is recognized, and minline
should be present if MinLine method is not dummy.
autohistory should be present if lines are put into history
automatically (maybe subject to MinLine), and addhistory if
addhistory method is not dummy.
If Features method reports a feature attribs as present, the
method Attribs is not dummy.
Additional supported functions
Actually Term::ReadLine can use some other package, that will support
reacher set of commands.
All these commands are callable via method interface and have names which
conform to standard conventions with the leading rl_ stripped.
The stub package included with the perl distribution allows some
additional methods:
tkRunning makes Tk event loop run when waiting for user input (i.e.,
during readline method).
ornaments makes the command line stand out by using termcap data. The
argument to ornaments should be 0, 1, or a string of a form
"aa,bb,cc,dd". Four components of this string should be
names of terminal capacities, first two will be issued to
make the prompt standout, last two to make the input line
standout.
newTTY takes two arguments which are input filehandle and output
filehandle. Switches to use these filehandles.
One can check whether the currently loaded ReadLine package supports
these methods by checking for corresponding Features.
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Term::ReadLine(3) Term::ReadLine(3)
EXPORTS
None
ENVIRONMENT
The variable PERL_RL governs which ReadLine clone is loaded. If the value
is false, a dummy interface is used. If the value is true, it should be
tail of the name of the package to use, such as Perl or Gnu.
If the variable is not set, the best available package is loaded.
no real package is found, substitutes stubs instead of basic functions."
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