path: root/lib/Term/Cap.pm

package Term::Cap;

use Carp;
use strict;

use vars qw($VERSION $VMS_TERMCAP);
use vars qw($termpat $state $first $entry);

$VERSION = '1.08';

# Version undef: Thu Dec 14 20:02:42 CST 1995 by sanders@bsdi.com
# Version 1.00:  Thu Nov 30 23:34:29 EST 2000 by schwern@pobox.com
#	[PATCH] $VERSION crusade, strict, tests, etc... all over lib/
# Version 1.01:  Wed May 23 00:00:00 CST 2001 by d-lewart@uiuc.edu
#	Avoid warnings in Tgetent and Tputs
# Version 1.02:  Sat Nov 17 13:50:39 GMT 2001 by jns@gellyfish.com
#       Altered layout of the POD
#       Added Test::More to PREREQ_PM in Makefile.PL
#       Fixed no argument Tgetent()
# Version 1.03:  Wed Nov 28 10:09:38 GMT 2001
#       VMS Support from Charles Lane <lane@DUPHY4.Physics.Drexel.Edu>
# Version 1.04:  Thu Nov 29 16:22:03 GMT 2001
#       Fixed warnings in test
# Version 1.05:  Mon Dec  3 15:33:49 GMT 2001
#       Don't try to fall back on infocmp if it's not there. From chromatic.
# Version 1.06:  Thu Dec  6 18:43:22 GMT 2001
#       Preload the default VMS termcap from Charles Lane
#       Don't carp at setting OSPEED unless warnings are on.
# Version 1.07:  Wed Jan  2 21:35:09 GMT 2002
#       Sanity check on infocmp output from Norton Allen
#       Repaired INSTALLDIRS thanks to Michael Schwern
# Version 1.08: Fri Aug 30 14:15:55 CEST 2002
#	Cope with comments lines from 'infocmp' from Brendan O'Dea

# TODO:
# support Berkeley DB termcaps
# should probably be a .xs module
# force $FH into callers package?
# keep $FH in object at Tgetent time?

=head1 NAME

Term::Cap - Perl termcap interface

=head1 SYNOPSIS

    require Term::Cap;
    $terminal = Tgetent Term::Cap { TERM => undef, OSPEED => $ospeed };
    $terminal->Trequire(qw/ce ku kd/);
    $terminal->Tgoto('cm', $col, $row, $FH);
    $terminal->Tputs('dl', $count, $FH);
    $terminal->Tpad($string, $count, $FH);

=head1 DESCRIPTION

These are low-level functions to extract and use capabilities from
a terminal capability (termcap) database.

More information on the terminal capabilities will be found in the
termcap manpage on most Unix-like systems.

=head2 METHODS

=over 4

The output strings for B<Tputs> are cached for counts of 1 for performance.
B<Tgoto> and B<Tpad> do not cache.  C<$self-E<gt>{_xx}> is the raw termcap
data and C<$self-E<gt>{xx}> is the cached version.

    print $terminal->Tpad($self->{_xx}, 1);

B<Tgoto>, B<Tputs>, and B<Tpad> return the string and will also
output the string to $FH if specified.


=cut

# Preload the default VMS termcap.
# If a different termcap is required then the text of one can be supplied
# in $Term::Cap::VMS_TERMCAP before Tgetent is called.

if ( $^O eq 'VMS') {
       chomp (my @entry = <DATA>);
       $VMS_TERMCAP = join '', @entry;
}

# Returns a list of termcap files to check.

sub termcap_path { ## private
    my @termcap_path;
    # $TERMCAP, if it's a filespec
    push(@termcap_path, $ENV{TERMCAP})
	if ((exists $ENV{TERMCAP}) &&
	    (($^O eq 'os2' || $^O eq 'MSWin32' || $^O eq 'dos')
	     ? $ENV{TERMCAP} =~ /^[a-z]:[\\\/]/is
	     : $ENV{TERMCAP} =~ /^\//s));
    if ((exists $ENV{TERMPATH}) && ($ENV{TERMPATH})) {
	# Add the users $TERMPATH
	push(@termcap_path, split(/(:|\s+)/, $ENV{TERMPATH}))
    }
    else {
	# Defaults
	push(@termcap_path,
	    $ENV{'HOME'} . '/.termcap',
	    '/etc/termcap',
	    '/usr/share/misc/termcap',
	);
    }

    # return the list of those termcaps that exist
    return grep(-f, @termcap_path);
}

=item B<Tgetent>

Returns a blessed object reference which the user can
then use to send the control strings to the terminal using B<Tputs>
and B<Tgoto>.

The function extracts the entry of the specified terminal
type I<TERM> (defaults to the environment variable I<TERM>) from the
database.

It will look in the environment for a I<TERMCAP> variable.  If
found, and the value does not begin with a slash, and the terminal
type name is the same as the environment string I<TERM>, the
I<TERMCAP> string is used instead of reading a termcap file.  If
it does begin with a slash, the string is used as a path name of
the termcap file to search.  If I<TERMCAP> does not begin with a
slash and name is different from I<TERM>, B<Tgetent> searches the
files F<$HOME/.termcap>, F</etc/termcap>, and F</usr/share/misc/termcap>,
in that order, unless the environment variable I<TERMPATH> exists,
in which case it specifies a list of file pathnames (separated by
spaces or colons) to be searched B<instead>.  Whenever multiple
files are searched and a tc field occurs in the requested entry,
the entry it names must be found in the same file or one of the
succeeding files.  If there is a C<:tc=...:> in the I<TERMCAP>
environment variable string it will continue the search in the
files as above.

The extracted termcap entry is available in the object
as C<$self-E<gt>{TERMCAP}>.

It takes a hash reference as an argument with two optional keys:

=over 2

=item OSPEED

The terminal output bit rate (often mistakenly called the baud rate)
for this terminal - if not set a warning will be generated
and it will be defaulted to 9600.  I<OSPEED> can be be specified as
either a POSIX termios/SYSV termio speeds (where 9600 equals 9600) or
an old DSD-style speed ( where 13 equals 9600).


=item TERM

The terminal type whose termcap entry will be used - if not supplied it will
default to $ENV{TERM}: if that is not set then B<Tgetent> will croak.

=back

It calls C<croak> on failure.

=cut

sub Tgetent { ## public -- static method
    my $class = shift;
    my ($self) = @_;

    $self = {} unless defined $self;
    bless $self, $class;

    my($term,$cap,$search,$field,$max,$tmp_term,$TERMCAP);
    local($termpat,$state,$first,$entry);	# used inside eval
    local $_;

    # Compute PADDING factor from OSPEED (to be used by Tpad)
    if (! $self->{OSPEED}) {
        if ( $^W ) {
	   carp "OSPEED was not set, defaulting to 9600";
        }
	$self->{OSPEED} = 9600;
    }
    if ($self->{OSPEED} < 16) {
	# delays for old style speeds
	my @pad = (0,200,133.3,90.9,74.3,66.7,50,33.3,16.7,8.3,5.5,4.1,2,1,.5,.2);
	$self->{PADDING} = $pad[$self->{OSPEED}];
    }
    else {
	$self->{PADDING} = 10000 / $self->{OSPEED};
    }

    $self->{TERM} = ($self->{TERM} || $ENV{TERM} || croak "TERM not set");
    $term = $self->{TERM};	# $term is the term type we are looking for

    # $tmp_term is always the next term (possibly :tc=...:) we are looking for
    $tmp_term = $self->{TERM};
    # protect any pattern metacharacters in $tmp_term 
    $termpat = $tmp_term; $termpat =~ s/(\W)/\\$1/g;

    my $foo = (exists $ENV{TERMCAP} ? $ENV{TERMCAP} : '');

    # $entry is the extracted termcap entry
    if (($foo !~ m:^/:s) && ($foo =~ m/(^|\|)${termpat}[:|]/s)) {
	$entry = $foo;
    }

    my @termcap_path = termcap_path();

    unless (@termcap_path || $entry)
    {
	# last resort--fake up a termcap from terminfo 
	local $ENV{TERM} = $term;

        if ( $^O eq 'VMS' ) {
          $entry = $VMS_TERMCAP;
        }
        else {
           if ( grep { -x "$_/infocmp" } split /:/, $ENV{PATH} ) {
              eval {
                my $tmp = `infocmp -C 2>/dev/null`;
                $tmp =~ s/^#.*\n//gm;	# remove comments

                if (( $tmp !~ m%^/%s ) && ( $tmp =~ /(^|\|)${termpat}[:|]/s)) {
                   $entry = $tmp;
                }
              };
           }
        }
    }

    croak "Can't find a valid termcap file" unless @termcap_path || $entry;

    $state = 1;					# 0 == finished
						# 1 == next file
						# 2 == search again

    $first = 0;					# first entry (keeps term name)

    $max = 32;					# max :tc=...:'s

    if ($entry) {
	# ok, we're starting with $TERMCAP
	$first++;				# we're the first entry
	# do we need to continue?
	if ($entry =~ s/:tc=([^:]+):/:/) {
	    $tmp_term = $1;
	    # protect any pattern metacharacters in $tmp_term 
	    $termpat = $tmp_term; $termpat =~ s/(\W)/\\$1/g;
	}
	else {
	    $state = 0;				# we're already finished
	}
    }

    # This is eval'ed inside the while loop for each file
    $search = q{
	while (<TERMCAP>) {
	    next if /^\\t/ || /^#/;
	    if ($_ =~ m/(^|\\|)${termpat}[:|]/o) {
		chomp;
		s/^[^:]*:// if $first++;
		$state = 0;
		while ($_ =~ s/\\\\$//) {
		    defined(my $x = <TERMCAP>) or last;
		    $_ .= $x; chomp;
		}
		last;
	    }
	}
	defined $entry or $entry = '';
	$entry .= $_ if $_;
    };

    while ($state != 0) {
	if ($state == 1) {
	    # get the next TERMCAP
	    $TERMCAP = shift @termcap_path
		|| croak "failed termcap lookup on $tmp_term";
	}
	else {
	    # do the same file again
	    # prevent endless recursion
	    $max-- || croak "failed termcap loop at $tmp_term";
	    $state = 1;		# ok, maybe do a new file next time
	}

	open(TERMCAP,"< $TERMCAP\0") || croak "open $TERMCAP: $!";
	eval $search;
	die $@ if $@;
	close TERMCAP;

	# If :tc=...: found then search this file again
	$entry =~ s/:tc=([^:]+):/:/ && ($tmp_term = $1, $state = 2);
	# protect any pattern metacharacters in $tmp_term 
	$termpat = $tmp_term; $termpat =~ s/(\W)/\\$1/g;
    }

    croak "Can't find $term" if $entry eq '';
    $entry =~ s/:+\s*:+/:/g;				# cleanup $entry
    $entry =~ s/:+/:/g;					# cleanup $entry
    $self->{TERMCAP} = $entry;				# save it
    # print STDERR "DEBUG: $entry = ", $entry, "\n";

    # Precompile $entry into the object
    $entry =~ s/^[^:]*://;
    foreach $field (split(/:[\s:\\]*/,$entry)) {
	if (defined $field && $field =~ /^(\w\w)$/) {
	    $self->{'_' . $field} = 1 unless defined $self->{'_' . $1};
	    # print STDERR "DEBUG: flag $1\n";
	}
	elsif (defined $field && $field =~ /^(\w\w)\@/) {
	    $self->{'_' . $1} = "";
	    # print STDERR "DEBUG: unset $1\n";
	}
	elsif (defined $field && $field =~ /^(\w\w)#(.*)/) {
	    $self->{'_' . $1} = $2 unless defined $self->{'_' . $1};
	    # print STDERR "DEBUG: numeric $1 = $2\n";
	}
	elsif (defined $field && $field =~ /^(\w\w)=(.*)/) {
	    # print STDERR "DEBUG: string $1 = $2\n";
	    next if defined $self->{'_' . ($cap = $1)};
	    $_ = $2;
	    s/\\E/\033/g;
	    s/\\(\d\d\d)/pack('c',oct($1) & 0177)/eg;
	    s/\\n/\n/g;
	    s/\\r/\r/g;
	    s/\\t/\t/g;
	    s/\\b/\b/g;
	    s/\\f/\f/g;
	    s/\\\^/\377/g;
	    s/\^\?/\177/g;
	    s/\^(.)/pack('c',ord($1) & 31)/eg;
	    s/\\(.)/$1/g;
	    s/\377/^/g;
	    $self->{'_' . $cap} = $_;
	}
	# else { carp "junk in $term ignored: $field"; }
    }
    $self->{'_pc'} = "\0" unless defined $self->{'_pc'};
    $self->{'_bc'} = "\b" unless defined $self->{'_bc'};
    $self;
}

# $terminal->Tpad($string, $cnt, $FH);

=item B<Tpad>

Outputs a literal string with appropriate padding for the current terminal.

It takes three arguments:

=over 2

=item B<$string>

The literal string to be output.  If it starts with a number and an optional
'*' then the padding will be increased by an amount relative to this number,
if the '*' is present then this amount will me multiplied by $cnt.  This part
of $string is removed before output/

=item B<$cnt>

Will be used to modify the padding applied to string as described above.

=item B<$FH>

An optional filehandle (or IO::Handle ) that output will be printed to.

=back

The padded $string is returned.

=cut

sub Tpad { ## public
    my $self = shift;
    my($string, $cnt, $FH) = @_;
    my($decr, $ms);

    if (defined $string && $string =~ /(^[\d.]+)(\*?)(.*)$/) {
	$ms = $1;
	$ms *= $cnt if $2;
	$string = $3;
	$decr = $self->{PADDING};
	if ($decr > .1) {
	    $ms += $decr / 2;
	    $string .= $self->{'_pc'} x ($ms / $decr);
	}
    }
    print $FH $string if $FH;
    $string;
}

# $terminal->Tputs($cap, $cnt, $FH);

=item B<Tputs>

Output the string for the given capability padded as appropriate without
any parameter substitution.

It takes three arguments:

=over 2

=item B<$cap>

The capability whose string is to be output.

=item B<$cnt>

A count passed to Tpad to modify the padding applied to the output string.
If $cnt is zero or one then the resulting string will be cached.

=item B<$FH>

An optional filehandle (or IO::Handle ) that output will be printed to.

=back

The appropriate string for the capability will be returned.

=cut

sub Tputs { ## public
    my $self = shift;
    my($cap, $cnt, $FH) = @_;
    my $string;

    $cnt = 0 unless $cnt;

    if ($cnt > 1) {
	$string = Tpad($self, $self->{'_' . $cap}, $cnt);
    } else {
	# cache result because Tpad can be slow
	unless (exists $self->{$cap}) {
	    $self->{$cap} = exists $self->{"_$cap"} ?
		Tpad($self, $self->{"_$cap"}, 1) : undef;
	}
	$string = $self->{$cap};
    }
    print $FH $string if $FH;
    $string;
}

# $terminal->Tgoto($cap, $col, $row, $FH);

=item B<Tgoto>

B<Tgoto> decodes a cursor addressing string with the given parameters.

There are four arguments:

=over 2

=item B<$cap>

The name of the capability to be output.

=item B<$col>

The first value to be substituted in the output string ( usually the column
in a cursor addressing capability )

=item B<$row>

The second value to be substituted in the output string (usually the row
in cursor addressing capabilities)

=item B<$FH>

An optional filehandle (or IO::Handle ) to which the output string will be
printed.

=back

Substitutions are made with $col and $row in the output string with the
following sprintf() line formats:

 %%   output `%'
 %d   output value as in printf %d
 %2   output value as in printf %2d
 %3   output value as in printf %3d
 %.   output value as in printf %c
 %+x  add x to value, then do %.

 %>xy if value > x then add y, no output
 %r   reverse order of two parameters, no output
 %i   increment by one, no output
 %B   BCD (16*(value/10)) + (value%10), no output

 %n   exclusive-or all parameters with 0140 (Datamedia 2500)
 %D   Reverse coding (value - 2*(value%16)), no output (Delta Data)

The output string will be returned.

=cut

sub Tgoto { ## public
    my $self = shift;
    my($cap, $code, $tmp, $FH) = @_;
    my $string = $self->{'_' . $cap};
    my $result = '';
    my $after = '';
    my $online = 0;
    my @tmp = ($tmp,$code);
    my $cnt = $code;

    while ($string =~ /^([^%]*)%(.)(.*)/) {
	$result .= $1;
	$code = $2;
	$string = $3;
	if ($code eq 'd') {
	    $result .= sprintf("%d",shift(@tmp));
	}
	elsif ($code eq '.') {
	    $tmp = shift(@tmp);
	    if ($tmp == 0 || $tmp == 4 || $tmp == 10) {
		if ($online) {
		    ++$tmp, $after .= $self->{'_up'} if $self->{'_up'};
		}
		else {
		    ++$tmp, $after .= $self->{'_bc'};
		}
	    }
	    $result .= sprintf("%c",$tmp);
	    $online = !$online;
	}
	elsif ($code eq '+') {
	    $result .= sprintf("%c",shift(@tmp)+ord($string));
	    $string = substr($string,1,99);
	    $online = !$online;
	}
	elsif ($code eq 'r') {
	    ($code,$tmp) = @tmp;
	    @tmp = ($tmp,$code);
	    $online = !$online;
	}
	elsif ($code eq '>') {
	    ($code,$tmp,$string) = unpack("CCa99",$string);
	    if ($tmp[$[] > $code) {
		$tmp[$[] += $tmp;
	    }
	}
	elsif ($code eq '2') {
	    $result .= sprintf("%02d",shift(@tmp));
	    $online = !$online;
	}
	elsif ($code eq '3') {
	    $result .= sprintf("%03d",shift(@tmp));
	    $online = !$online;
	}
	elsif ($code eq 'i') {
	    ($code,$tmp) = @tmp;
	    @tmp = ($code+1,$tmp+1);
	}
	else {
	    return "OOPS";
	}
    }
    $string = Tpad($self, $result . $string . $after, $cnt);
    print $FH $string if $FH;
    $string;
}

# $terminal->Trequire(qw/ce ku kd/);

=item B<Trequire>

Takes a list of capabilities as an argument and will croak if one is not
found.

=cut

sub Trequire { ## public
    my $self = shift;
    my($cap,@undefined);
    foreach $cap (@_) {
	push(@undefined, $cap)
	    unless defined $self->{'_' . $cap} && $self->{'_' . $cap};
    }
    croak "Terminal does not support: (@undefined)" if @undefined;
}

=back

=head1 EXAMPLES

    use Term::Cap;

    # Get terminal output speed
    require POSIX;
    my $termios = new POSIX::Termios;
    $termios->getattr;
    my $ospeed = $termios->getospeed;

    # Old-style ioctl code to get ospeed:
    #     require 'ioctl.pl';
    #     ioctl(TTY,$TIOCGETP,$sgtty);
    #     ($ispeed,$ospeed) = unpack('cc',$sgtty);

    # allocate and initialize a terminal structure
    $terminal = Tgetent Term::Cap { TERM => undef, OSPEED => $ospeed };

    # require certain capabilities to be available
    $terminal->Trequire(qw/ce ku kd/);

    # Output Routines, if $FH is undefined these just return the string

    # Tgoto does the % expansion stuff with the given args
    $terminal->Tgoto('cm', $col, $row, $FH);

    # Tputs doesn't do any % expansion.
    $terminal->Tputs('dl', $count = 1, $FH);

=head1 COPYRIGHT AND LICENSE

Please see the README file in distribution.

=head1 AUTHOR

This module is part of the core Perl distribution and is also maintained
for CPAN by Jonathan Stowe <jns@gellyfish.com>.

=head1 SEE ALSO

termcap(5)

=cut

# Below is a default entry for systems where there are terminals but no
# termcap
1;
__DATA__
vt220|vt200|DEC VT220 in vt100 emulation mode:
am:mi:xn:xo:
co#80:li#24:
RA=\E[?7l:SA=\E[?7h:
ac=kkllmmjjnnwwqquuttvvxx:ae=\E(B:al=\E[L:as=\E(0:
bl=^G:cd=\E[J:ce=\E[K:cl=\E[H\E[2J:cm=\E[%i%d;%dH:
cr=^M:cs=\E[%i%d;%dr:dc=\E[P:dl=\E[M:do=\E[B:
ei=\E[4l:ho=\E[H:im=\E[4h:
is=\E[1;24r\E[24;1H:
nd=\E[C:
kd=\E[B::kl=\E[D:kr=\E[C:ku=\E[A:le=^H:
mb=\E[5m:md=\E[1m:me=\E[m:mr=\E[7m:
kb=\0177:
r2=\E>\E[24;1H\E[?3l\E[?4l\E[?5l\E[?7h\E[?8h\E=:rc=\E8:
sc=\E7:se=\E[27m:sf=\ED:so=\E[7m:sr=\EM:ta=^I:
ue=\E[24m:up=\E[A:us=\E[4m:ve=\E[?25h:vi=\E[?25l: