Initial bulk commit for "Git on MSys"

[msysgit/historical-msysgit.git] / lib / perl5 / 5.6.1 / chat2.pl

# chat.pl: chat with a server
#
# This library is no longer being maintained, and is included for backward
# compatibility with Perl 4 programs which may require it.
#
# In particular, this should not be used as an example of modern Perl
# programming techniques.
#
# Suggested alternative: Socket
#
# Based on: V2.01.alpha.7 91/06/16
# Randal L. Schwartz (was <merlyn@stonehenge.com>)
# multihome additions by A.Macpherson@bnr.co.uk
# allow for /dev/pts based systems by Joe Doupnik <JRD@CC.USU.EDU>

package chat;

require 'sys/socket.ph';

if( defined( &main'PF_INET ) ){
        $pf_inet = &main'PF_INET;
        $sock_stream = &main'SOCK_STREAM;
        local($name, $aliases, $proto) = getprotobyname( 'tcp' );
        $tcp_proto = $proto;
}
else {
        # XXX hardwired $PF_INET, $SOCK_STREAM, 'tcp'
        # but who the heck would change these anyway? (:-)
        $pf_inet = 2;
        $sock_stream = 1;
        $tcp_proto = 6;
}


$sockaddr = 'S n a4 x8';
chop($thishost = `hostname`);

# *S = symbol for current I/O, gets assigned *chatsymbol....
$next = "chatsymbol000000"; # next one
$nextpat = "^chatsymbol"; # patterns that match next++, ++, ++, ++


## $handle = &chat'open_port("server.address",$port_number);
## opens a named or numbered TCP server

sub open_port { ## public
        local($server, $port) = @_;

        local($serveraddr,$serverproc);

        # We may be multi-homed, start with 0, fixup once connexion is made
        $thisaddr = "\0\0\0\0" ;
        $thisproc = pack($sockaddr, 2, 0, $thisaddr);

        *S = ++$next;
        if ($server =~ /^(\d+)+\.(\d+)\.(\d+)\.(\d+)$/) {
                $serveraddr = pack('C4', $1, $2, $3, $4);
        } else {
                local(@x) = gethostbyname($server);
                return undef unless @x;
                $serveraddr = $x[4];
        }
        $serverproc = pack($sockaddr, 2, $port, $serveraddr);
        unless (socket(S, $pf_inet, $sock_stream, $tcp_proto)) {
                ($!) = ($!, close(S)); # close S while saving $!
                return undef;
        }
        unless (bind(S, $thisproc)) {
                ($!) = ($!, close(S)); # close S while saving $!
                return undef;
        }
        unless (connect(S, $serverproc)) {
                ($!) = ($!, close(S)); # close S while saving $!
                return undef;
        }
# We opened with the local address set to ANY, at this stage we know
# which interface we are using.  This is critical if our machine is
# multi-homed, with IP forwarding off, so fix-up.
        local($fam,$lport);
        ($fam,$lport,$thisaddr) = unpack($sockaddr, getsockname(S));
        $thisproc = pack($sockaddr, 2, 0, $thisaddr);
# end of post-connect fixup
        select((select(S), $| = 1)[0]);
        $next; # return symbol for switcharound
}

## ($host, $port, $handle) = &chat'open_listen([$port_number]);
## opens a TCP port on the current machine, ready to be listened to
## if $port_number is absent or zero, pick a default port number
## process must be uid 0 to listen to a low port number

sub open_listen { ## public

        *S = ++$next;
        local($thisport) = shift || 0;
        local($thisproc_local) = pack($sockaddr, 2, $thisport, $thisaddr);
        local(*NS) = "__" . time;
        unless (socket(NS, $pf_inet, $sock_stream, $tcp_proto)) {
                ($!) = ($!, close(NS));
                return undef;
        }
        unless (bind(NS, $thisproc_local)) {
                ($!) = ($!, close(NS));
                return undef;
        }
        unless (listen(NS, 1)) {
                ($!) = ($!, close(NS));
                return undef;
        }
        select((select(NS), $| = 1)[0]);
        local($family, $port, @myaddr) =
                unpack("S n C C C C x8", getsockname(NS));
        $S{"needs_accept"} = *NS; # so expect will open it
        (@myaddr, $port, $next); # returning this
}

## $handle = &chat'open_proc("command","arg1","arg2",...);
## opens a /bin/sh on a pseudo-tty

sub open_proc { ## public
        local(@cmd) = @_;

        *S = ++$next;
        local(*TTY) = "__TTY" . time;
        local($pty,$tty) = &_getpty(S,TTY);
        die "Cannot find a new pty" unless defined $pty;
        $pid = fork;
        die "Cannot fork: $!" unless defined $pid;
        unless ($pid) {
                close STDIN; close STDOUT; close STDERR;
                setpgrp(0,$$);
                if (open(DEVTTY, "/dev/tty")) {
                    ioctl(DEVTTY,0x20007471,0);         # XXX s/b &TIOCNOTTY
                    close DEVTTY;
                }
                open(STDIN,"<&TTY");
                open(STDOUT,">&TTY");
                open(STDERR,">&STDOUT");
                die "Oops" unless fileno(STDERR) == 2;  # sanity
                close(S);
                exec @cmd;
                die "Cannot exec @cmd: $!";
        }
        close(TTY);
        $next; # return symbol for switcharound
}

# $S is the read-ahead buffer

## $return = &chat'expect([$handle,] $timeout_time,
##      $pat1, $body1, $pat2, $body2, ... )
## $handle is from previous &chat'open_*().
## $timeout_time is the time (either relative to the current time, or
## absolute, ala time(2)) at which a timeout event occurs.
## $pat1, $pat2, and so on are regexs which are matched against the input
## stream.  If a match is found, the entire matched string is consumed,
## and the corresponding body eval string is evaled.
##
## Each pat is a regular-expression (probably enclosed in single-quotes
## in the invocation).  ^ and $ will work, respecting the current value of $*.
## If pat is 'TIMEOUT', the body is executed if the timeout is exceeded.
## If pat is 'EOF', the body is executed if the process exits before
## the other patterns are seen.
##
## Pats are scanned in the order given, so later pats can contain
## general defaults that won't be examined unless the earlier pats
## have failed.
##
## The result of eval'ing body is returned as the result of
## the invocation.  Recursive invocations are not thought
## through, and may work only accidentally. :-)
##
## undef is returned if either a timeout or an eof occurs and no
## corresponding body has been defined.
## I/O errors of any sort are treated as eof.

$nextsubname = "expectloop000000"; # used for subroutines

sub expect { ## public
        if ($_[0] =~ /$nextpat/) {
                *S = shift;
        }
        local($endtime) = shift;

        local($timeout,$eof) = (1,1);
        local($caller) = caller;
        local($rmask, $nfound, $timeleft, $thisbuf);
        local($cases, $pattern, $action, $subname);
        $endtime += time if $endtime < 600_000_000;

        if (defined $S{"needs_accept"}) { # is it a listen socket?
                local(*NS) = $S{"needs_accept"};
                delete $S{"needs_accept"};
                $S{"needs_close"} = *NS;
                unless(accept(S,NS)) {
                        ($!) = ($!, close(S), close(NS));
                        return undef;
                }
                select((select(S), $| = 1)[0]);
        }

        # now see whether we need to create a new sub:

        unless ($subname = $expect_subname{$caller,@_}) {
                # nope.  make a new one:
                $expect_subname{$caller,@_} = $subname = $nextsubname++;

                $cases .= <<"EDQ"; # header is funny to make everything elsif's
sub $subname {
        LOOP: {
                if (0) { ; }
EDQ
                while (@_) {
                        ($pattern,$action) = splice(@_,0,2);
                        if ($pattern =~ /^eof$/i) {
                                $cases .= <<"EDQ";
                elsif (\$eof) {
                        package $caller;
                        $action;
                }
EDQ
                                $eof = 0;
                        } elsif ($pattern =~ /^timeout$/i) {
                        $cases .= <<"EDQ";
                elsif (\$timeout) {
                        package $caller;
                        $action;
                }
EDQ
                                $timeout = 0;
                        } else {
                                $pattern =~ s#/#\\/#g;
                        $cases .= <<"EDQ";
                elsif (\$S =~ /$pattern/) {
                        \$S = \$';
                        package $caller;
                        $action;
                }
EDQ
                        }
                }
                $cases .= <<"EDQ" if $eof;
                elsif (\$eof) {
                        undef;
                }
EDQ
                $cases .= <<"EDQ" if $timeout;
                elsif (\$timeout) {
                        undef;
                }
EDQ
                $cases .= <<'ESQ';
                else {
                        $rmask = "";
                        vec($rmask,fileno(S),1) = 1;
                        ($nfound, $rmask) =
                                select($rmask, undef, undef, $endtime - time);
                        if ($nfound) {
                                $nread = sysread(S, $thisbuf, 1024);
                                if ($nread > 0) {
                                        $S .= $thisbuf;
                                } else {
                                        $eof++, redo LOOP; # any error is also eof
                                }
                        } else {
                                $timeout++, redo LOOP; # timeout
                        }
                        redo LOOP;
                }
        }
}
ESQ
                eval $cases; die "$cases:\n$@" if $@;
        }
        $eof = $timeout = 0;
        do $subname();
}

## &chat'print([$handle,] @data)
## $handle is from previous &chat'open().
## like print $handle @data

sub print { ## public
        if ($_[0] =~ /$nextpat/) {
                *S = shift;
        }

        local $out = join $, , @_;
        syswrite(S, $out, length $out);
        if( $chat'debug ){
                print STDERR "printed:";
                print STDERR @_;
        }
}

## &chat'close([$handle,])
## $handle is from previous &chat'open().
## like close $handle

sub close { ## public
        if ($_[0] =~ /$nextpat/) {
                *S = shift;
        }
        close(S);
        if (defined $S{"needs_close"}) { # is it a listen socket?
                local(*NS) = $S{"needs_close"};
                delete $S{"needs_close"};
                close(NS);
        }
}

## @ready_handles = &chat'select($timeout, @handles)
## select()'s the handles with a timeout value of $timeout seconds.
## Returns an array of handles that are ready for I/O.
## Both user handles and chat handles are supported (but beware of
## stdio's buffering for user handles).

sub select { ## public
        local($timeout) = shift;
        local(@handles) = @_;
        local(%handlename) = ();
        local(%ready) = ();
        local($caller) = caller;
        local($rmask) = "";
        for (@handles) {
                if (/$nextpat/o) { # one of ours... see if ready
                        local(*SYM) = $_;
                        if (length($SYM)) {
                                $timeout = 0; # we have a winner
                                $ready{$_}++;
                        }
                        $handlename{fileno($_)} = $_;
                } else {
                        $handlename{fileno(/'/ ? $_ : "$caller\'$_")} = $_;
                }
        }
        for (sort keys %handlename) {
                vec($rmask, $_, 1) = 1;
        }
        select($rmask, undef, undef, $timeout);
        for (sort keys %handlename) {
                $ready{$handlename{$_}}++ if vec($rmask,$_,1);
        }
        sort keys %ready;
}

# ($pty,$tty) = $chat'_getpty(PTY,TTY):
# internal procedure to get the next available pty.
# opens pty on handle PTY, and matching tty on handle TTY.
# returns undef if can't find a pty.
# Modify "/dev/pty" to "/dev/pts" for Dell Unix v2.2 (aka SVR4.04). Joe Doupnik.

sub _getpty { ## private
        local($_PTY,$_TTY) = @_;
        $_PTY =~ s/^([^']+)$/(caller)[$[]."'".$1/e;
        $_TTY =~ s/^([^']+)$/(caller)[$[]."'".$1/e;
        local($pty, $tty, $kind);
        if( -e "/dev/pts000" ){         ## mods by Joe Doupnik Dec 1992
                $kind = "pts";          ## SVR4 Streams
        } else {
                $kind = "pty";          ## BSD Clist stuff
        }
        for $bank (112..127) {
                next unless -e sprintf("/dev/$kind%c0", $bank);
                for $unit (48..57) {
                        $pty = sprintf("/dev/$kind%c%c", $bank, $unit);
                        open($_PTY,"+>$pty") || next;
                        select((select($_PTY), $| = 1)[0]);
                        ($tty = $pty) =~ s/pty/tty/;
                        open($_TTY,"+>$tty") || next;
                        select((select($_TTY), $| = 1)[0]);
                        system "stty nl>$tty";
                        return ($pty,$tty);
                }
        }
        undef;
}

1;