366 lines
9.8 KiB
Perl
366 lines
9.8 KiB
Perl
=head1 NAME
|
|
|
|
Term::ReadLine - Perl interface to various C<readline> packages. If
|
|
no real package is found, substitutes stubs instead of basic functions.
|
|
|
|
=head1 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/;
|
|
}
|
|
|
|
=head1 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.
|
|
|
|
=head1 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-E<gt>Init.
|
|
|
|
=over 12
|
|
|
|
=item C<ReadLine>
|
|
|
|
returns the actual package that executes the commands. Among possible
|
|
values are C<Term::ReadLine::Gnu>, C<Term::ReadLine::Perl>,
|
|
C<Term::ReadLine::Stub Exporter>.
|
|
|
|
=item C<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 C<IN> and C<OUT> filehandles. These
|
|
arguments should be globs.
|
|
|
|
=item C<readline>
|
|
|
|
gets an input line, I<possibly> with actual C<readline>
|
|
support. Trailing newline is removed. Returns C<undef> on C<EOF>.
|
|
|
|
=item C<addhistory>
|
|
|
|
adds the line to the history of input, from where it can be used if
|
|
the actual C<readline> is present.
|
|
|
|
=item C<IN>, $C<OUT>
|
|
|
|
return the filehandles for input and output or C<undef> if C<readline>
|
|
input and output cannot be used for Perl.
|
|
|
|
=item C<MinLine>
|
|
|
|
If argument is specified, it is an advice on minimal size of line to
|
|
be included into history. C<undef> means do not include anything into
|
|
history. Returns the old value.
|
|
|
|
=item C<findConsole>
|
|
|
|
returns an array with two strings that give most appropriate names for
|
|
files for input and output using conventions C<"E<lt>$in">, C<"E<gt>out">.
|
|
|
|
=item 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 C<rl_> stripped.
|
|
|
|
=item C<Features>
|
|
|
|
Returns a reference to a hash with keys being features present in
|
|
current implementation. Several optional features are used in the
|
|
minimal interface: C<appname> should be present if the first argument
|
|
to C<new> is recognized, and C<minline> should be present if
|
|
C<MinLine> method is not dummy. C<autohistory> should be present if
|
|
lines are put into history automatically (maybe subject to
|
|
C<MinLine>), and C<addhistory> if C<addhistory> method is not dummy.
|
|
|
|
If C<Features> method reports a feature C<attribs> as present, the
|
|
method C<Attribs> is not dummy.
|
|
|
|
=back
|
|
|
|
=head1 Additional supported functions
|
|
|
|
Actually C<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 C<rl_> stripped.
|
|
|
|
The stub package included with the perl distribution allows some
|
|
additional methods:
|
|
|
|
=over 12
|
|
|
|
=item C<tkRunning>
|
|
|
|
makes Tk event loop run when waiting for user input (i.e., during
|
|
C<readline> method).
|
|
|
|
=item C<ornaments>
|
|
|
|
makes the command line stand out by using termcap data. The argument
|
|
to C<ornaments> should be 0, 1, or a string of a form
|
|
C<"aa,bb,cc,dd">. Four components of this string should be names of
|
|
I<terminal capacities>, first two will be issued to make the prompt
|
|
standout, last two to make the input line standout.
|
|
|
|
=item C<newTTY>
|
|
|
|
takes two arguments which are input filehandle and output filehandle.
|
|
Switches to use these filehandles.
|
|
|
|
=back
|
|
|
|
One can check whether the currently loaded ReadLine package supports
|
|
these methods by checking for corresponding C<Features>.
|
|
|
|
=head1 EXPORTS
|
|
|
|
None
|
|
|
|
=head1 ENVIRONMENT
|
|
|
|
The environment variable C<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
|
|
C<Perl> or C<Gnu>.
|
|
|
|
As a special case, if the value of this variable is space-separated,
|
|
the tail might be used to disable the ornaments by setting the tail to
|
|
be C<o=0> or C<ornaments=0>. The head should be as described above, say
|
|
|
|
If the variable is not set, or if the head of space-separated list is
|
|
empty, the best available package is loaded.
|
|
|
|
export "PERL_RL=Perl o=0" # Use Perl ReadLine without ornaments
|
|
export "PERL_RL= o=0" # Use best available ReadLine without ornaments
|
|
|
|
(Note that processing of C<PERL_RL> for ornaments is in the discretion of the
|
|
particular used C<Term::ReadLine::*> package).
|
|
|
|
=cut
|
|
|
|
package Term::ReadLine::Stub;
|
|
@ISA = qw'Term::ReadLine::Tk Term::ReadLine::TermCap';
|
|
|
|
$DB::emacs = $DB::emacs; # To peacify -w
|
|
*rl_term_set = \@Term::ReadLine::TermCap::rl_term_set;
|
|
|
|
sub ReadLine {'Term::ReadLine::Stub'}
|
|
sub readline {
|
|
my $self = shift;
|
|
my ($in,$out,$str) = @$self;
|
|
print $out $rl_term_set[0], shift, $rl_term_set[1], $rl_term_set[2];
|
|
$self->register_Tk
|
|
if not $Term::ReadLine::registered and $Term::ReadLine::toloop
|
|
and defined &Tk::DoOneEvent;
|
|
#$str = scalar <$in>;
|
|
$str = $self->get_line;
|
|
print $out $rl_term_set[3];
|
|
# bug in 5.000: chomping empty string creats length -1:
|
|
chomp $str if defined $str;
|
|
$str;
|
|
}
|
|
sub addhistory {}
|
|
|
|
sub findConsole {
|
|
my $console;
|
|
|
|
if (-e "/dev/tty") {
|
|
$console = "/dev/tty";
|
|
} elsif (-e "con" or $^O eq 'MSWin32') {
|
|
$console = "con";
|
|
} else {
|
|
$console = "sys\$command";
|
|
}
|
|
|
|
if (($^O eq 'amigaos') || ($^O eq 'beos')) {
|
|
$console = undef;
|
|
}
|
|
elsif ($^O eq 'os2') {
|
|
if ($DB::emacs) {
|
|
$console = undef;
|
|
} else {
|
|
$console = "/dev/con";
|
|
}
|
|
}
|
|
|
|
$consoleOUT = $console;
|
|
$console = "&STDIN" unless defined $console;
|
|
if (!defined $consoleOUT) {
|
|
$consoleOUT = defined fileno(STDERR) ? "&STDERR" : "&STDOUT";
|
|
}
|
|
($console,$consoleOUT);
|
|
}
|
|
|
|
sub new {
|
|
die "method new called with wrong number of arguments"
|
|
unless @_==2 or @_==4;
|
|
#local (*FIN, *FOUT);
|
|
my ($FIN, $FOUT, $ret);
|
|
if (@_==2) {
|
|
($console, $consoleOUT) = findConsole;
|
|
|
|
open(FIN, "<$console");
|
|
open(FOUT,">$consoleOUT");
|
|
#OUT->autoflush(1); # Conflicts with debugger?
|
|
$sel = select(FOUT);
|
|
$| = 1; # for DB::OUT
|
|
select($sel);
|
|
$ret = bless [\*FIN, \*FOUT];
|
|
} else { # Filehandles supplied
|
|
$FIN = $_[2]; $FOUT = $_[3];
|
|
#OUT->autoflush(1); # Conflicts with debugger?
|
|
$sel = select($FOUT);
|
|
$| = 1; # for DB::OUT
|
|
select($sel);
|
|
$ret = bless [$FIN, $FOUT];
|
|
}
|
|
if ($ret->Features->{ornaments}
|
|
and not ($ENV{PERL_RL} and $ENV{PERL_RL} =~ /\bo\w*=0/)) {
|
|
local $Term::ReadLine::termcap_nowarn = 1;
|
|
$ret->ornaments(1);
|
|
}
|
|
return $ret;
|
|
}
|
|
|
|
sub newTTY {
|
|
my ($self, $in, $out) = @_;
|
|
$self->[0] = $in;
|
|
$self->[1] = $out;
|
|
my $sel = select($out);
|
|
$| = 1; # for DB::OUT
|
|
select($sel);
|
|
}
|
|
|
|
sub IN { shift->[0] }
|
|
sub OUT { shift->[1] }
|
|
sub MinLine { undef }
|
|
sub Attribs { {} }
|
|
|
|
my %features = (tkRunning => 1, ornaments => 1, 'newTTY' => 1);
|
|
sub Features { \%features }
|
|
|
|
package Term::ReadLine; # So late to allow the above code be defined?
|
|
|
|
my ($which) = exists $ENV{PERL_RL} ? split /\s+/, $ENV{PERL_RL} : undef;
|
|
if ($which) {
|
|
if ($which =~ /\bgnu\b/i){
|
|
eval "use Term::ReadLine::Gnu;";
|
|
} elsif ($which =~ /\bperl\b/i) {
|
|
eval "use Term::ReadLine::Perl;";
|
|
} else {
|
|
eval "use Term::ReadLine::$which;";
|
|
}
|
|
} elsif (defined $which and $which ne '') { # Defined but false
|
|
# Do nothing fancy
|
|
} else {
|
|
eval "use Term::ReadLine::Gnu; 1" or eval "use Term::ReadLine::Perl; 1";
|
|
}
|
|
|
|
#require FileHandle;
|
|
|
|
# To make possible switch off RL in debugger: (Not needed, work done
|
|
# in debugger).
|
|
|
|
if (defined &Term::ReadLine::Gnu::readline) {
|
|
@ISA = qw(Term::ReadLine::Gnu Term::ReadLine::Stub);
|
|
} elsif (defined &Term::ReadLine::Perl::readline) {
|
|
@ISA = qw(Term::ReadLine::Perl Term::ReadLine::Stub);
|
|
} else {
|
|
@ISA = qw(Term::ReadLine::Stub);
|
|
}
|
|
|
|
package Term::ReadLine::TermCap;
|
|
|
|
# Prompt-start, prompt-end, command-line-start, command-line-end
|
|
# -- zero-width beautifies to emit around prompt and the command line.
|
|
@rl_term_set = ("","","","");
|
|
# string encoded:
|
|
$rl_term_set = ',,,';
|
|
|
|
sub LoadTermCap {
|
|
return if defined $terminal;
|
|
|
|
require Term::Cap;
|
|
$terminal = Tgetent Term::Cap ({OSPEED => 9600}); # Avoid warning.
|
|
}
|
|
|
|
sub ornaments {
|
|
shift;
|
|
return $rl_term_set unless @_;
|
|
$rl_term_set = shift;
|
|
$rl_term_set ||= ',,,';
|
|
$rl_term_set = 'us,ue,md,me' if $rl_term_set eq '1';
|
|
my @ts = split /,/, $rl_term_set, 4;
|
|
eval { LoadTermCap };
|
|
unless (defined $terminal) {
|
|
warn("Cannot find termcap: $@\n") unless $Term::ReadLine::termcap_nowarn;
|
|
$rl_term_set = ',,,';
|
|
return;
|
|
}
|
|
@rl_term_set = map {$_ ? $terminal->Tputs($_,1) || '' : ''} @ts;
|
|
return $rl_term_set;
|
|
}
|
|
|
|
|
|
package Term::ReadLine::Tk;
|
|
|
|
$count_handle = $count_DoOne = $count_loop = 0;
|
|
|
|
sub handle {$giveup = 1; $count_handle++}
|
|
|
|
sub Tk_loop {
|
|
# Tk->tkwait('variable',\$giveup); # needs Widget
|
|
$count_DoOne++, Tk::DoOneEvent(0) until $giveup;
|
|
$count_loop++;
|
|
$giveup = 0;
|
|
}
|
|
|
|
sub register_Tk {
|
|
my $self = shift;
|
|
$Term::ReadLine::registered++
|
|
or Tk->fileevent($self->IN,'readable',\&handle);
|
|
}
|
|
|
|
sub tkRunning {
|
|
$Term::ReadLine::toloop = $_[1] if @_ > 1;
|
|
$Term::ReadLine::toloop;
|
|
}
|
|
|
|
sub get_c {
|
|
my $self = shift;
|
|
$self->Tk_loop if $Term::ReadLine::toloop && defined &Tk::DoOneEvent;
|
|
return getc $self->IN;
|
|
}
|
|
|
|
sub get_line {
|
|
my $self = shift;
|
|
$self->Tk_loop if $Term::ReadLine::toloop && defined &Tk::DoOneEvent;
|
|
my $in = $self->IN;
|
|
local ($/) = "\n";
|
|
return scalar <$in>;
|
|
}
|
|
|
|
1;
|
|
|