parallel: implemented --tag

src/parallel

@@ -398,6 +398,7 @@ sub options_hash {
 	 "shellquote|shell_quote|shell-quote" => \$::opt_shellquote,
 	 "nice=i" => \$::opt_nice,
 	 "timeout=i" => \$::opt_timeout,
+	 "tag" => \$::opt_tag,
 	 "onall" => \$::opt_onall,
 	 "nonall" => \$::opt_nonall,
 	 "sshlogin|S=s" => \@::opt_sshlogin,
@@ -1678,6 +1679,11 @@ sub usage {
 	 "--recstart str Record start separator for --pipe.",
 	 "",
 	 "See 'man $Global::progname' for details",
+	 "",
+	 "When using GNU Parallel for a publication please cite:",
+	 "",
+	 "O. Tange (2011): GNU Parallel - The Command-Line Power Tool,",
+	 ";login: The USENIX Magazine, February 2011:42-47.",
 	 "");
 }
 
@@ -3461,22 +3467,37 @@ sub print {
     if($Global::debug) {
 	print STDERR "ERR:\n";
     }
+    if($::opt_tag) {
+	my $tag = $self->{'commandline'}->args_as_string();
+	while(<$err>) {
+	    print STDERR $tag,"\t",$_;
+	}
+    } else {
 	my $buf;
 	while(sysread($err,$buf,1000_000)) {
 	    print STDERR $buf;
 	}
+    }
     flush STDERR;
 
     if($::opt_files) {
 	print STDOUT $self->{'stdoutfilename'},"\n";
     } else {
+	my $buf;
 	seek $out, 0, 0;
 	if($Global::debug) {
 	    print STDOUT "OUT:\n";
 	}
+	if($::opt_tag) {
+	    my $tag = $self->{'commandline'}->args_as_string();
+	    while(<$out>) {
+		print STDOUT $tag,"\t",$_;
+	    }
+	} else {
 	    while(sysread($out,$buf,1000_000)) {
 		print STDOUT $buf;
 	    }
+	}
 	flush STDOUT;
 	::debug("<<joboutput $command\n");
     }
@@ -3691,6 +3712,14 @@ sub number_of_args {
     return $#{$self->{'arg_list'}}+1;
 }
 
+sub args_as_string {
+    # Returns:
+    #  all unmodified arguments joined with ' ' (similar to {})
+    my $self = shift;
+    return (join " ", map { $_->orig() }
+	    map { @$_ } @{$self->{'arg_list'}});
+}
+
 sub len {
     # The length of the command line with args substituted
     my $self = shift;

src/parallel.pod

@@ -1148,6 +1148,12 @@ and it will open a tty for the job. When the job is done, the next job
 will get the tty.
 
 
+=item B<--tag>
+
+Tag lines with arguments. Each output line will be prepended with the
+arguments and TAB (\t).
+
+
 =item B<--tmpdir> I<dirname>
 
 Directory for temporary files. GNU B<parallel> normally buffers output

testsuite/tests-to-run/test20.sh

@@ -12,4 +12,11 @@ echo '### Test --use-cpus-instead-of-cores'
 echo 'Cores should complete first on machines with less than 4 physical CPUs'
 wait
 
+echo '### Test --tag ::: a ::: b'
+stdout parallel -k --tag -j1  echo stderr-{.} ">&2;" echo stdout-{} ::: a ::: b
 
+echo '### Test --tag ::: a b'
+stdout parallel -k --tag -j1  echo stderr-{.} ">&2;" echo stdout-{} ::: a b
+
+echo '### Test --tag -X ::: a b'
+stdout parallel -k --tag -X -j1  echo stderr-{.} ">&2;" echo stdout-{} ::: a b

testsuite/wanted-results/test20

@@ -6,3 +6,14 @@
 Cores should complete first on machines with less than 4 physical CPUs
 cores done
 CPUs done
+### Test --tag ::: a ::: b
+a b	stderr-a b
+a b	stdout-a b
+### Test --tag ::: a b
+a	stderr-a
+a	stdout-a
+b	stderr-b
+b	stdout-b
+### Test --tag -X ::: a b
+a b	stderr-a stderr-b
+a b	stdout-a stdout-b