#!/usr/bin/perl --
# Perl wrapper around rsh/remsh to export DISPLAY and run an xterm
# Usage:
#  remoteshell hostname [-l remoteuser]

$rsh= 'ssh';
$usesh= '';

$rsh= shift if $ARGV[0] =~ s/^-r//;
$usesh= shift if $ARGV[0] =~ s/^-s//;

($remotehost= shift) || die "need hostname\n";
$remotehost= (gethostbyname($remotehost))[0] || $remotehost;

if ($ARGV[0] eq '-l') {
    shift;
    ($remoteuser= shift) || die "need username after -l\n";
    $remoteuser= "-l $remoteuser";
} elsif (open(H,"$ENV{'HOME'}/.rhosts")) {
    while (<H>) {
        m/^(\S+)\s+(\S+)\s*$/ || next;
        if (&canon($1) eq &canon($remotehost)) {
            $remoteuser= "-l $2";
            last;
        }
    }
}

$_= $ENV{'DISPLAY'};
m/:/ || die "\$DISPLAY variable format `$_' bad";
$ENV{'DISPLAY'}= &canon($`).':'.$';

sub canon {
    local ($h) = @_;
    local ($v,@h,@v);
    chomp($h= `hostname`) unless length($h);
    @h= gethostbyname($h);
    return $h unless @h;
    @v= gethostbyaddr($h[4],$h[2]);
    $v= $v[0];
#    unless ($v =~ m/\./) {
#        $v .= '.';
#        $v .= `domainname`;
#        $v =~ s/\n$//;
#    }
    return $v;
}

open(U,"|$rsh $remotehost $remoteuser perl")
    || die "failed to run $rsh: $!";

print U <<'END' ;
    $_= <DATA>; chop; @ar= split(/\0/,$_) if length($_);
    $_= <DATA>; chop; $ENV{'DISPLAY'}= $_;
    $_= <DATA>; chop; $usesh= $_;
    $host= <DATA>; chop($host);
    $pcmd= '. .configs/setenvir; echo ok $PATH';
    $pout= `$pcmd`;
    $pout =~ m/^ok (\S+)\n$/ || die "pcmd gave `$pout'";
    $ENV{'PATH'}= $1;
    open(X,"|xauth nmerge -");
    while (<DATA>) { print X; }
    close(X);
    $? && die "xauth gave code $?";
    defined($c= fork) || die "fork: $!";
    exit 0 if $c;
    close(STDIN); close(STDOUT);
    open(STDIN,"</dev/null") || die "/dev/null for stdin: $!";
    open(STDOUT,">>.remoteshell-errors") || die "append .remoteshell-errors: $!";
    chmod(0600,".remoteshell-errors");
    close(STDERR); open(STDERR,">&STDOUT");
    if ($usesh eq '') {
        exec('close3onwards','xterm','-T',$host,@ar,'-e','.configs/rxprofile');
    } else {
	exec('close3onwards',$usesh,'-xc','. .configs/setenvir; exec "$@"','-',@ar);
    }
    print STDERR "close3onwards: $!\n";
    exit 1;
__END__
END

print U join("\0",@ARGV),"\n";
print U $ENV{'DISPLAY'},"\n";
print U $usesh,"\n";
print U $remotehost,"\n";
print U `xauth nextract - $ENV{'DISPLAY'}`;

close(U);
$? && die "remoteshell $rsh gave code $?";

exit 0;