--- loncom/lonmaxima	2006/03/04 06:44:11	1.8
+++ loncom/lonmaxima	2006/03/08 22:30:11	1.16
@@ -3,7 +3,7 @@
 # The LearningOnline Network with CAPA
 # Connect to MAXIMA CAS
 #
-# $Id: lonmaxima,v 1.8 2006/03/04 06:44:11 albertel Exp $
+# $Id: lonmaxima,v 1.16 2006/03/08 22:30:11 www Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -30,7 +30,7 @@
 # http://www.lon-capa.org/
 #
 
- 
+use Expect; 
 use IPC::Open3;
 use IO::Select;
 use IO::Socket;
@@ -55,54 +55,6 @@ my $lastlog;                           #
 use vars qw($PREFORK $MAX_CLIENTS_PER_CHILD %children $children $status
 	    $pidfile $port %perlvar $lastlog);
  
-sub maximareply {
-    my ($cmd) = @_;
-    my $reply='';
-    my $error='';
-    my $exitstatus='';
-
-    unless ($cmd=~/\;\n$/) { $cmd.=";\n"; }
-
-    my ($cmd_in, $cmd_out, $cmd_err);
-    my $maximapid = open3($cmd_in, $cmd_out, $cmd_err, 'maxima');
-    $children{$maximapid} = 1;
-    
-    print $cmd_in $cmd;
-    close($cmd_in);
-
-    &status("Command sent");
-
-    $SIG{ALRM} = sub { kill 9 => $maximapid; }; 
-    alarm(5);
-    no strict 'refs';
-
-    my $selector = IO::Select->new();
-
-    $selector->add($cmd_err, $cmd_out);
-    
-    while (my @ready = $selector->can_read()) {
-	foreach my $fh (@ready) {
-	    if (fileno($fh) == fileno($cmd_err)) {
-		$error.=<$cmd_err>;
-	    } else {
-		my $line = scalar(<$cmd_out>);
-                if ($line=~/^(\(\%o|\s)/) {
-		    $line=~s/^\(.*\)/     /; 
-		    $reply.=$line; 
-		}
-	    }
-	    $selector->remove($fh) if eof($fh);
-	}
-    }
-    alarm(0);
-    $SIG{ALRM} = 'DEFAULT';
-    close($cmd_out);
-    close($cmd_err);
-    use strict 'refs';
-    &status("Command processed");
-    return ($reply,$error,$exitstatus);
-}
- 
 # ------------------------------------------------------------ Service routines 
 sub REAPER {                        # takes care of dead children 
                                     # and MAXIMA processes
@@ -247,15 +199,15 @@ close(PIDSAVE);
 &status('Starting');
      
 
+# Install signal handlers.
+$SIG{CHLD} = \&REAPER;
+$SIG{INT}  = $SIG{TERM} = \&HUNTSMAN;
+ 
 # Fork off our children.
 for (1 .. $PREFORK) {
     &make_new_child($server);
 }
  
-# Install signal handlers.
-$SIG{CHLD} = \&REAPER;
-$SIG{INT}  = $SIG{TERM} = \&HUNTSMAN;
- 
 # And maintain the population.
 while (1) {
     &status('Parent process, sleeping');
@@ -291,10 +243,25 @@ sub make_new_child {
         sigprocmask(SIG_UNBLOCK, $sigset)
             or die("Can't unblock SIGINT for fork: $!\n");
 
-	&process_requests($server);
+        my $command=Expect->spawn('maxima');
+        $command->log_stdout(0);
+
+        &getmaximaoutput($command);
+
+        for (my $i=0; $i < $MAX_CLIENTS_PER_CHILD; $i++) {
+           &status('Accepting connections');
+           my $client = $server->accept()     or last;
+           while (my $cmd=<$client>) {
+              &status('Processing command');
+              print $command &unescape($cmd).";\n";
+              print $client &escape(&getmaximaoutput($command))."\n";
+           }
+        }
 
         # tidy up gracefully and finish
 
+        $command->soft_close();
+
         # this exit is VERY important, otherwise the child will become
         # a producer of more and more children, forking yourself into
         # process death.
@@ -302,15 +269,20 @@ sub make_new_child {
     }
 }
 
-sub process_requests {
-    my ($server) = @_;
-    # handle connections until we've reached $MAX_CLIENTS_PER_CHILD
-    for (my $i=0; $i < $MAX_CLIENTS_PER_CHILD; $i++) {
-	&status('Accepting connections');     
-	my $client = $server->accept()     or last;
-	while (my $cmd=<$client>) {
-	    &status('Processing command');
-	    print $client &escape((&maximareply(&unescape($cmd)))[0])."\n";
-	}
-    }    
+sub getmaximaoutput {
+    my ($command)=@_;
+    my (undef,undef,undef,$output)=$command->expect(20, -re => '\(\%i\d+\)');
+    my $foundoutput=0;
+    my $realoutput='';
+    foreach my $line (split(/\n/,$output)) {
+       if ($line=~/\;/) { $foundoutput=1; next; }
+       if (!$foundoutput) { next; }
+       my ($label)=($line=~s/^(\(\%o\d+\))//);
+       if ($label) {
+          $label=~s/\S/ /g;
+          $line=$label.$line;
+       }
+       $realoutput.=$line."\n";
+    }
+    return $realoutput;
 }