package Term::Complete;
require 5.000;
require Exporter;

use strict;
our @ISA = qw(Exporter);
our @EXPORT = qw(Complete);
our $VERSION = '1.4';

#      @(#)complete.pl,v1.2            ([email protected]) 09/23/91

=head1 NAME

Term::Complete - Perl word completion module

=head1 SYNOPSIS

    $input = Complete('prompt_string', \@completion_list);
    $input = Complete('prompt_string', @completion_list);

=head1 DESCRIPTION

This routine provides word completion on the list of words in
the array (or array ref).

The tty driver is put into raw mode and restored using an operating
system specific command, in UNIX-like environments C<stty>.

The following command characters are defined:

=over 4

=item E<lt>tabE<gt>

Attempts word completion.
Cannot be changed.

=item ^D

Prints completion list.
Defined by I<$Term::Complete::complete>.

=item ^U

Erases the current input.
Defined by I<$Term::Complete::kill>.

=item E<lt>delE<gt>, E<lt>bsE<gt>

Erases one character.
Defined by I<$Term::Complete::erase1> and I<$Term::Complete::erase2>.

=back

=head1 DIAGNOSTICS

Bell sounds when word completion fails.

=head1 BUGS

The completion character E<lt>tabE<gt> cannot be changed.

=head1 AUTHOR

Wayne Thompson

=cut

our($complete, $kill, $erase1, $erase2, $tty_raw_noecho, $tty_restore, $stty);
our($tty_saved_state) = '';
CONFIG: {
    $complete = "\004";
    $kill     = "\025";
    $erase1 =   "\177";
    $erase2 =   "\010";
    foreach my $s (qw(/bin/stty /usr/bin/stty)) {
	if (-x $s) {
	    $tty_raw_noecho = "$s raw -echo";
	    $tty_restore    = "$s -raw echo";
	    $stty = $s;
	    last;
	}
    }
}

sub Complete {
    my($prompt, @cmp_lst, $cmp, $test, $l, @match);
    my ($return, $r) = ("", 0);

    $return = "";
    $r      = 0;

    $prompt = shift;
    if (ref $_[0] || $_[0] =~ /^\*/) {
	@cmp_lst = sort @{$_[0]};
    }
    else {
	@cmp_lst = sort(@_);
    }

    # Attempt to save the current stty state, to be restored later
    if (defined $stty && defined $tty_saved_state && $tty_saved_state eq '') {
	$tty_saved_state = qx($stty -g 2>/dev/null);
	if ($?) {
	    # stty -g not supported
	    $tty_saved_state = undef;
	}
	else {
	    $tty_restore = qq($stty "$tty_saved_state");
	}
    }
    system $tty_raw_noecho if defined $tty_raw_noecho;
    LOOP: {
        print($prompt, $return);
        while (($_ = getc(STDIN)) ne "\r") {
            CASE: {
                # (TAB) attempt completion
                $_ eq "\t" && do {
                    @match = grep(/^\Q$return/, @cmp_lst);
                    unless ($#match < 0) {
                        $l = length($test = shift(@match));
                        foreach $cmp (@match) {
                            until (substr($cmp, 0, $l) eq substr($test, 0, $l)) {
                                $l--;
                            }
                        }
                        print("\a");
                        print($test = substr($test, $r, $l - $r));
                        $r = length($return .= $test);
                    }
                    last CASE;
                };

                # (^D) completion list
                $_ eq $complete && do {
                    print(join("\r\n", '', grep(/^\Q$return/, @cmp_lst)), "\r\n");
                    redo LOOP;
                };

                # (^U) kill
                $_ eq $kill && do {
                    if ($r) {
                        $r	= 0;
			$return	= "";
                        print("\r\n");
                        redo LOOP;
                    }
                    last CASE;
                };

                # (DEL) || (BS) erase
                ($_ eq $erase1 || $_ eq $erase2) && do {
                    if($r) {
                        print("\b \b");
                        chop($return);
                        $r--;
                    }
                    last CASE;
                };

                # printable char
                ord >= 32 && do {
                    $return .= $_;
                    $r++;
                    print;
                    last CASE;
                };
            }
        }
    }
    system $tty_restore if defined $tty_restore;
    print("\n");
    $return;
}

1;