--retries works (possibly breaking something else).

doc/haikus

@@ -43,7 +43,6 @@ GNU parallel has helped me kill a Hadoop cluster before.
   gnu parallel and emacs).
     -- Peter Kjellström @nsccap@twitter
 
-
   GNU/Parallel umm... tempting.
     -- k-leb k @dcatdemon@twitter
 
@@ -53,12 +52,10 @@ GNU parallel has helped me kill a Hadoop cluster before.
   Not sure if it counts as an "alt" tool but GNU parallel really took my shell scripting game to the next level.
     -- @alinajaf@twitter
 
-
 === Used ===
   [L]earning about parallel was amazing for me, it gives us many beautiful solutions.
      -- SergioAraujo@stackoverflow
 
-
   I've said it before: The command line program GNU Parallel is a godsend.
     -- Jo Chr. Oterhals @oterhals
 

src/parallel

@@ -949,18 +949,30 @@ sub spreadstdin() {
     my $blocksize = $Global::blocksize;
     my $in = *STDIN;
     my $header = find_header(\$buf,$in);
+    my $timeout = 3;
     while(1) {
       my $anything_written = 0;
       my $buflen = length $buf;
       my $readsize = ($buflen < $blocksize) ? $blocksize-$buflen : $blocksize;
       # If $buf < $blocksize, append so it is $blocksize long after reading.
       # Otherwise append a full $blocksize
+      local $SIG{ALRM} = sub {
+	  ::set_fh_non_blocking($in);
+	  read($in,substr($buf,$buflen,0),$readsize);
+	  ::set_fh_blocking($in);
+#	  warn("ee $buf");
+	  alarm $timeout;
+      };
+    #  alarm $timeout;
       if(not read($in,substr($buf,$buflen,0),$readsize)) {
+#	  warn("ff");
 	  # End-of-file
 	  $chunk_number != 1 and last;
 	  # Force the while-loop once if everything was read by header reading
 	  $one_time_through++ and last;
       }
+ #     warn("yy");
+  #    alarm 0;
       if($opt::r) {
 	  # Remove empty lines
 	  $buf =~ s/^\s*\n//gm;
@@ -2071,7 +2083,7 @@ sub check_invalid_option_combinations() {
 
 sub init_globals() {
     # Defaults:
-    $Global::version = 20191122;
+    $Global::version = 20191023;
     $Global::progname = 'parallel';
     $::name = "GNU Parallel";
     $Global::infinity = 2**31;
@@ -7954,6 +7966,29 @@ sub free_slot($) {
     }
 }
 
+{
+    my $which_sh;
+    
+    sub startshell($) {
+	my $self = shift;
+
+	# Shell must support 'exec >foo 2>bar'
+	# Using sh always will cause functions to not be exported
+	# Could perl be used instead?
+	$which_sh = $Global::cshell ? "/bin/sh" : $Global::shell;
+	my ($pid, $stdin);
+	if($pid = open($stdin, "|-", $which_sh)) {
+	    my $fileno = fileno($stdin);
+	    # Assume we get pid, fileno from spawner child
+	    $self->{'pid'} = $pid;
+	    open(my $stdin_fh, ">&=$fileno") or die ($fileno);
+	    $self->set_fh(0,"w",$stdin_fh);
+	} else {
+	    die();
+	}
+    }
+}
+    
 sub openoutputfiles($) {
     # Open files for STDOUT and STDERR
     # Set file handles in $self->fh
@@ -7964,20 +7999,21 @@ sub openoutputfiles($) {
        ($opt::keeporder or $opt::files or $opt::results or
 	$opt::compress or $opt::compress_program or
 	$opt::decompress_program)) {
-	# Do not save to files: Use non-blocking pipe
 	my ($outfhr, $errfhr);
-	pipe($outfhr, $outfhw) || die;
+	$outname = ::tmpfifo();
-	pipe($errfhr, $errfhw) || die;
+	$errname = ::tmpfifo();
-	$self->set_fh(1,'w',$outfhw);
+	open($outfhr,"+<",$outname);
-	$self->set_fh(2,'w',$errfhw);
+	open($errfhr,"+<",$errname);
 	$self->set_fh(1,'r',$outfhr);
 	$self->set_fh(2,'r',$errfhr);
+	open($outfhw,"+>",$outname);
+	open($errfhw,"+>",$errname);
+	$self->set_fh(1,'w',$outfhw);
+	$self->set_fh(2,'w',$errfhw);
 	# Make it possible to read non-blocking from the pipe
 	for my $fdno (1,2) {
 	    ::set_fh_non_blocking($self->fh($fdno,'r'));
 	}
-	# Return immediately because we do not need setting filenames
-	return;
     } elsif($opt::results and not $Global::csvsep) {
 	my $out = $self->{'commandline'}->results_out();
 	my $seqname;
@@ -8037,8 +8073,8 @@ sub openoutputfiles($) {
 	}
     } else {
 	# --ungroup
-	open($outfhw,">&",$Global::fd{1}) || die;
+#	open($outfhw,">&",$Global::fd{1}) || die;
-	open($errfhw,">&",$Global::fd{2}) || die;
+#	open($errfhw,">&",$Global::fd{2}) || die;
 	# File name must be empty as it will otherwise be printed
 	$outname = "";
 	$errname = "";
@@ -8046,15 +8082,31 @@ sub openoutputfiles($) {
 	$self->set_fh(2,"unlink",$errname);
     }
     # Set writing FD
-    $self->set_fh(1,'w',$outfhw);
+#    $self->set_fh(1,'w',$outfhw);
-    $self->set_fh(2,'w',$errfhw);
+#    $self->set_fh(2,'w',$errfhw);
     $self->set_fh(1,'name',$outname);
     $self->set_fh(2,'name',$errname);
+    
     if($opt::compress) {
 	$self->filter_through_compress();
     } elsif(not $opt::ungroup) {
 	$self->grouped();
     }
+    my $in = $self->fh(0,'w');
+    if($outname) {
+	syswrite($in,"exec >$outname\n");
+	# Must be unlinked by worker child
+	my $n = $self->fh(1,"unlink");
+	if(-e $n) { syswrite($in,"rm $n\n"); }
+    } elsif($errname) {
+	syswrite($in,"exec 2>$errname\n");
+	# Must be unlinked by worker child
+	my $n = $self->fh(2,"unlink");
+	if(-e $n) { syswrite($in,"rm $n\n"); }
+    }
+#    close $outfhw;
+#    close $errfhw;
+    
     if($opt::linebuffer) {
 	# Make it possible to read non-blocking from
 	# the buffer files
@@ -8114,7 +8166,7 @@ sub grouped($) {
 	    ::die_bug("fdr: Cannot open ".$self->fh($fdno,'name'));
 	$self->set_fh($fdno,'r',$fdr);
 	# Unlink if not debugging
-	$Global::debug or ::rm($self->fh($fdno,"unlink"));
+#	$Global::debug or ::rm($self->fh($fdno,"unlink"));
     }
 }
 
@@ -9278,15 +9330,23 @@ sub start($) {
 	open OUT, '>&', $stdout_fh or ::die_bug("Can't dup STDOUT: $!");
 	open ERR, '>&', $stderr_fh or ::die_bug("Can't dup STDERR: $!");
 	# The eval is needed to catch exception from open3
-	eval {
+#	eval {
-	    if(not $pid = ::open3($stdin_fh, ">&OUT", ">&ERR", "-")) {
+#	    if(not $pid = ::open3($stdin_fh, ">&OUT", ">&ERR", "-")) {
-		# Each child gets its own process group to make it safe to killall
+#		# Each child gets its own process group to make it safe to killall
-		eval{ setpgrp(0,0) };
+#		eval{ setpgrp(0,0) };
-		eval{ setpriority(0,0,$opt::nice) };
+#		eval{ setpriority(0,0,$opt::nice) };
-		exec($Global::shell,"-c",$command)
+#		exec($Global::shell,"-c",$command)
-		    || ::die_bug("open3-$stdin_fh $command");
+#		    || ::die_bug("open3-$stdin_fh $command");
-	    }
+#	    }
-	};
+#	};
+#	my ($in,$out,$err);
+#	if($pid = open($in, "|-", "/bin/sh")) {
+#	    $fileno = fileno($in);
+#	}
+	# $pid $fileno
+#	$stdin_fh = $self->fh("w",0)
+#	print $stdin_fh $command;
+	
 	return $pid;
     }
 
@@ -9366,7 +9426,7 @@ sub start($) {
 	eval $redefine_eval;
     }
 
-    sub open3_setpgrp {
+    sub _open3_setpgrp {
 	my $setgprp_cache = $Global::cache_dir . "/tmp/sshlogin/" .
 	    ::hostname() . "/setpgrp_func";
 	if(-e $setgprp_cache) {
@@ -9395,55 +9455,47 @@ sub start($) {
 	# $job->skip() was called
 	$command = "true";
     }
+    $ENV{'PARALLEL_SEQ'} = $job->seq();
+    $ENV{'PARALLEL_PID'} = $$;
+    $ENV{'PARALLEL_TMP'} = ::tmpname("par");
+    $job->startshell();
     $job->openoutputfiles();
     $job->print_verbose_dryrun();
     # Call slot to store the slot value
     $job->slot();
-    my($stdout_fh,$stderr_fh) = ($job->fh(1,"w"),$job->fh(2,"w"));
     if($opt::dryrun or $opt::sqlmaster) { $command = "true"; }
-    $ENV{'PARALLEL_SEQ'} = $job->seq();
-    $ENV{'PARALLEL_PID'} = $$;
-    $ENV{'PARALLEL_TMP'} = ::tmpname("par");
     $job->add_rm($ENV{'PARALLEL_TMP'});
     ::debug("run", $Global::total_running, " processes . Starting (",
 	    $job->seq(), "): $command\n");
+
+    my ($stdin_fh) = $job->fh(0,"w");
+    if ($opt::tty and -c "/dev/tty" and
+	open(my $devtty_fh, "<", "/dev/tty")) {
+	# Give /dev/tty to the command if no one else is using it
+	close $devtty_fh;
+	syswrite($stdin_fh,"exec < /dev/tty\n");
+    }
+    my @setpgrp = ('exec perl','-e',
+		   ::Q("eval\{setpgrp\}\;eval\{setpriority\(0,0,$opt::nice\)\}\;".
+		       "exec '$Global::shell', '-c', \@ARGV"));
+    syswrite($stdin_fh,"@setpgrp ".::Q($command)."\n");
+#    print $stdin_fh "@setpgrp ",::Q($command),"\n";
+    ::debug("run", "Run: $command\n");
     if($opt::pipe) {
-	my ($stdin_fh) = ::gensym();
-	$pid = open3_setpgrp($stdin_fh,$stdout_fh,$stderr_fh,$command);
 	if($opt::roundrobin and not $opt::keeporder) {
 	    # --keep-order will make sure the order will be reproducible
 	    ::set_fh_non_blocking($stdin_fh);
 	}
-	$job->set_fh(0,"w",$stdin_fh);
 	if($opt::tee or $opt::shard or $opt::bin) { $job->set_virgin(0); }
-    } elsif ($opt::tty and -c "/dev/tty" and
-	     open(my $devtty_fh, "<", "/dev/tty")) {
-	# Give /dev/tty to the command if no one else is using it
-	# The eval is needed to catch exception from open3
-	local (*IN,*OUT,*ERR);
-	open OUT, '>&', $stdout_fh or ::die_bug("Can't dup STDOUT: $!");
-	open ERR, '>&', $stderr_fh or ::die_bug("Can't dup STDERR: $!");
-	*IN = $devtty_fh;
-	# The eval is needed to catch exception from open3
-	my @wrap = ('perl','-e',
-			    "eval\{setpriority\(0,0,$opt::nice\)\}\;".
-			    "exec '$Global::shell', '-c', \@ARGV");
-	eval {
-	    $pid = ::open3("<&IN", ">&OUT", ">&ERR", @wrap, $command)
-		|| ::die_bug("open3-/dev/tty");
-	    1;
-	};
-	close $devtty_fh;
-	$job->set_virgin(0);
     } else {
-	$pid = open3_setpgrp(::gensym(),$stdout_fh,$stderr_fh,$command);
+	# Close stdin if not pipe input
+	close $stdin_fh;
 	$job->set_virgin(0);
     }
-    if($pid) {
+    if($job->{'pid'}) {
 	# A job was started
 	$Global::total_running++;
 	$Global::total_started++;
-	$job->set_pid($pid);
 	$job->set_starttime();
 	$Global::running{$job->pid()} = $job;
 	if($opt::timeout) {
@@ -9999,9 +10051,12 @@ sub print_tag(@) {
 sub free_ressources() {
     my $self = shift;
     if(not $opt::ungroup) {
+	my $fh;
 	for my $fdno (sort { $a <=> $b } keys %Global::fd) {
-	    close $self->fh($fdno,"w");
+	    $fh = $self->fh($fdno,"w");
-	    close $self->fh($fdno,"r");
+	    $fh and close $fh;
+	    $fh = $self->fh($fdno,"r");
+	    $fh and close $fh;
 	}
     }
 }
@@ -10010,7 +10065,7 @@ sub print_normal($) {
     my $self = shift;
     my ($fdno,$in_fh,$out_fd) = @_;
     my $buf;
-    close $self->fh($fdno,"w");
+    #close $self->fh($fdno,"w");
     if($? and $opt::compress) {
 	::error($opt::compress_program." failed.");
 	$self->set_exitstatus(255);