From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Fri, 19 Jun 2009 17:04:54 +0000 (+0100)
Subject: WIP yppsc-parsedb-updatereceiver; pipeval works
X-Git-Tag: 1.9.2~115^2~2
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~yarrgweb/git?p=ypp-sc-tools.db-live.git;a=commitdiff_plain;h=e9fe421133870b68103e6cfcf1a1e06058edf032

WIP yppsc-parsedb-updatereceiver; pipeval works
---

diff --git a/pctb/yppsc-parsedb-updatereceiver b/pctb/yppsc-parsedb-updatereceiver
index 1bce6c5..5d5585e 100755
--- a/pctb/yppsc-parsedb-updatereceiver
+++ b/pctb/yppsc-parsedb-updatereceiver
@@ -22,9 +22,8 @@ $CGI::POST_MAX= 65536;
 $CGI::DISABLE_UPLOADS= 1;
 
 use CGI qw/:standard -private_tempfiles/;
-use IPC::Open2;
+use IO::Pipe;
 use IO::Handle;
-use File::Temp;
 
 #---------- pixmaps ----------
 
@@ -52,11 +51,12 @@ sub parseentryin__pixmap ($) {
     }
 
     my $summary= pipeval($ppm,
-			 'set -x; cat >&2',
 			 'ppmtopgm',
 			 'pnmscale -width 79',
 			 'pnmnorm -bpercent 40 -wpercent 10',
-			 'pgmtopbm -threshold');
+			 'pgmtopbm -threshold',
+			 'pbmtoascii'
+			 );
     print STDERR ">$summary<\n";
     
 
@@ -74,36 +74,40 @@ sub pipeval ($@) {
     my ($val, @cmds) = @_;
     my (@pids);
 
-    my $paste_child= open PIPEVAL_PASTE, "-|";
-    defined $paste_child or die $!;
-    if (!$paste_child) { print $val or die $!; exit 0; }
-
-    my $f= 'PIPEVAL_PASTE';
-
-$_=<$f>;
-print STDERR ">$_<\n";
-
-    foreach my $cmd (@cmds) {
-	my $newf;
-print STDERR "$cmd | $f\n";
-	push @pids, open2($newf, "<& $f", $cmd);
-#	if (@pids>1) { close $f or die $!; }
-print STDERR "$cmd | $f $newf @pids\n";
-	$f= $newf;
+    my $lastpipe;
+    
+    foreach my $cmd ('',@cmds) {
+	my $pipe= new IO::Pipe or die $!;
+	my $pid= fork();  defined $pid or die $!;
+
+	if (!$pid) {
+	    $pipe->writer();
+	    if (!$lastpipe) {
+		 print $pipe $val or die $!;
+		 exit 0;
+	     } else {
+		 open STDIN, '<&', $lastpipe or die $!;
+		 open STDOUT, '>&', $pipe or die $!;
+		 close $lastpipe or die $!;
+		 close $pipe or die $!;
+		 exec $cmd; die $!;
+	     }
+	}
+	$pipe->reader();
+	if ($lastpipe) { close $lastpipe or die $!; }
+	$lastpipe= $pipe;
+	push @pids, $pid;
     }
 
-    $!=0; { local ($/)=undef; $val= <$f>; }
+    $!=0; { local ($/)=undef; $val= <$lastpipe>; }
     defined $val or die $!;
-    $f->error and die $!;  close $f or die $!;
-
-    waitpid($paste_child,0) == $paste_child or die "paste $? $!";
-    $?==0 or $?==13 or die "paste $?";
-    close PIPEVAL_PASTE or die $!;
+    $lastpipe->error and die $!;  close $lastpipe or die $!;
 
-    foreach my $cmd (@cmds) {
+    foreach my $cmd ('(paste)', @cmds) {
 	my $pid= shift @pids;
 	waitpid($pid,0) == $pid or die "$pid $? $!";
 	$?==0 or $?==13 or die "$cmd $?";
+print STDERR "OK $cmd\n";
     }
     return $val;
 }