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## chat.pl: chat with a server | |
## V2.01.alpha.7 91/06/16 | |
## Randal L. Schwartz | |
package chat; | |
$sockaddr = 'S n a4 x8'; | |
chop($thishost = `hostname`); $thisaddr = (gethostbyname($thishost))[4]; | |
$thisproc = pack($sockaddr, 2, 0, $thisaddr); | |
# *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,$serverproc); | |
*S = ++$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, 2, 1, 6)) { | |
# XXX hardwired $AF_SOCKET, $SOCK_STREAM, 'tcp' | |
# but who the heck would change these anyway? (:-) | |
($!) = ($!, 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; | |
} | |
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, 2, 1, 6)) { | |
# XXX hardwired $AF_SOCKET, $SOCK_STREAM, 'tcp' | |
# but who the heck would change these anyway? (:-) | |
($!) = ($!, 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 $pty; | |
local($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] =~ /$nextpat/) { | |
*S = shift; | |
} | |
print S @_; | |
} | |
## &chat'close([$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) = $chat'_getpty(PTY,TTY): | |
# internal procedure to get the next available pty. | |
# opens pty on handle PTY, and matching tty on handle TTY. | |
# returns undef if can't find a pty. | |
sub _getpty { ## private | |
local($_PTY,$_TTY) = @_; | |
$_PTY =~ s/^([^']+)$/(caller)[$[]."'".$1/e; | |
$_TTY =~ s/^([^']+)$/(caller)[$[]."'".$1/e; | |
local($pty,$tty); | |
for $bank (112..127) { | |
next unless -e sprintf("/dev/pty%c0", $bank); | |
for $unit (48..57) { | |
$pty = sprintf("/dev/pty%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; |