- Re-organised the documentation.

- Modularised how the list of packages in a task is determined.

Makefile

@@ -32,6 +32,7 @@ updatetaskspo:
 install:
 	install -d $(DESTDIR)/usr/bin $(DESTDIR)$(TASKDIR) \
 		$(DESTDIR)/usr/lib/tasksel/tests \
+		$(DESTDIR)/usr/lib/tasksel/packages \
 		$(DESTDIR)/usr/share/man/man8
 	install -m 755 tasksel.pl $(DESTDIR)/usr/bin/tasksel
 	install -m 755 tasksel-debconf $(DESTDIR)/usr/lib/tasksel/

README

@@ -6,13 +6,70 @@ On startup, the tasksel program will read all *.desc files in
 tasks will be presented in a simple list selection screen with their short
 descriptions.
 
-On exit, tasksel executes the appropriate apt-get command to install the
-selected packages. If the -t option is given, then tasksel prints out the
-command line to use to stdout instead. All other messages are printed to
-stderr.
+On exit, tasksel executes the appropriate command to install the selected
+packages. If the -t option is given, then tasksel prints out the command
+line to use to stdout instead. All other messages are printed to stderr.
 
 To get a new task added, please file a bug report on tasksel.
 
 Debian derived distributions can add a new .desc file to
 /usr/share/tasksel/ to add additional tasks, or modify/divert
 debian-tasks.desc to remove tasks.
+
+The file format is a rfc-822 style stanza, with fields named Task, Section,
+Description (which should include an extended descrition), Key, Depends, 
+and optional Test- and Source fields. Here is an example:
+
+Task: desktop
+Section: user
+Relevance: 10
+Description: Desktop environment
+ This task provides basic "desktop" software, including a variety
+ of session managers, file managers and web browsers. It incorporates
+ both the GNOME and KDE desktops, and provides a display manager
+ which lets the user choose between the two.
+Key:
+  x-window-system-core
+  kde
+  gnome
+Packages: task-fields
+
+The Key field lists packages that are essential to the task. If those
+packages are not available, then the task will not be available either. It
+need not list all the packages in the task, if some only serve to make it
+better when they are available.
+
+The Packages field tells how to get a complete list of packages that are in
+the task. In the example above, it uses the task-fields method, which is
+built into tasksel, and looks for Task fields in the control data of available
+packages, that list the name of the task. It's also possible to define
+other methods, by adding programs to /usr/lib/tasksel/packages/. Then
+list the name of the program as the value for the task field, and it will
+be run and passed the name of the task, and should output a list of
+packages in that task.
+
+There is support for automatically installing tasks based on test programs.
+If a task has a Test-* field, then a program in /usr/lib/tasksel/tests/
+will be run. For example Test-lang fields cause /usr/lib/tasksel/tests/lang
+to be run. The test is passed first the name of the tasks, and then the
+contents of the field as parameters. The exit code of the test controls
+what to do with the task:
+
+0 - do not display, but do install task
+1 - do not display task 
+2 - display task, marked for installation
+3 - display task, not marked for installation
+
+One use of these tests is in automatically selecting a language task
+appropriate for the user's locale, and hiding the rest. The lang test
+handles this by comparing the value of the Test-lang field of a task with
+the locale setting. Tests could also be used for things like automatically
+installing hardware support tasks on systems with the right hardware.
+
+There is rudimentary support for tasks that depend on other tasks. If a
+task has a Depends field, then it should only be installed if all the tasks
+listed as dependencies are installed.
+
+If a task is important enough that it should go near the top of its
+section, give it a relevance of 9 or 10. If a task is not likely to be
+used, give it a relevance of 1. Default is 5.

debian/changelog

@@ -5,6 +5,8 @@ tasksel (2.07) UNRELEASED; urgency=low
     - Document --new-install and long format switches.
     - Add --task-packages switch, may be used by Synaptic.
     - Add --task-desc switch. Closes: #259664
+    - Re-organised the documentation.
+    - Modularised how the list of packages in a task is determined.
   * Translations
     - Kęstutis Biliūnas
       - Updated Lithuanian translation of tasks.

makedesc.pl

@@ -98,6 +98,7 @@ sub processfile {
 	         grep(/^test-(.*)/, keys %fields)) {
 		print OUT ucfirst($_).": ".$fields{$_}."\n" if length $fields{$_};
 	}
+	print OUT "Packages: task-fields\n";
 	print OUT "\n";
 }
 

tasks/README

@@ -3,10 +3,10 @@ verious general tasks a user might want to perform with a Debian system,
 lists of packages that they might use to perform the tasks, and grouping
 information to make related sets of tasks appear together.
 
-The file format is a rfc-822 style stanza, with fields named Task, Section,
-Description (which should include an extended descrition), Key, and
-Packages. The Packages field should include the list of packages one per
-line after it, indented by one space each, like so:
+See the toplevel README for details about the file format. The files in
+this directory are preprocessed and may include comments by prefixing any
+line with a hash mark ("#"). Also, the Packages field is used in these files
+to list the packages that are part of each task, like so:
 
 Packages:
  foo
@@ -14,15 +14,15 @@ Packages:
  baz
  ...
 
-When the task is selected, any of those packages that are available will be
-selected.
-
-The Key field is the same, but packages listed in it must be available or
-the task should not be displayed at all. There's no need to list packages
-in the Packages field if they are listed as Key.
+List only real packages, not virtual packages.
+ 
+Packages listed for different tasks (and within a single task)
+should not conflict, or the results will be rather arbitrary.
 
-Comments may appear in the file, by prefixing a line with a hash mark
-('#').
+Packages that are only available on some architectures, or that may not
+be available on the user's installation media may still be listed. This
+is no problem, they are simply ignored in those cases. Take care listing
+such packages as Key however.
 
 Care should be taken when adding new tasks to ensure that the new task is
 suitably generic -- it should be something of value to a large number (at
@@ -35,38 +35,6 @@ appropriate test program. No more than 10 tasks should ever be displayed by
 the program, so if there are more, the least-used tasks must be removed
 when adding a new one.
 
-There is support for automatically installing tasks based on test programs.
-If a task has a Test-* field, then a program in /usr/lib/tasksel/tests/
-will be run. For example Test-lang fields cause /usr/lib/tasksel/tests/lang
-to be run. The test is passed first the name of the tasks, and then the
-contents of the field as parameters. The exit code of the test controls
-what to do with the task:
-
-0 - do not display, but do install task
-1 - do not display task
-2 - display task, marked for installation
-3 - display task, not marked for installation
-
-One use of these tests is in automatically selecting a language task
-appropriate for the user's locale, and hiding the rest. The lang test
-handles this by comparing the value of the Test-lang field of a task with
-the locale setting. Tests could also be used for things like automatically
-installing hardware support tasks on systems with the right hardware.
-
-There is rudimentary support for tasks that depend on other tasks. If a
-task has a Depends field, then it should only be installed if all the tasks
-listed as dependencies are installed.
-
-Packages listed for different tasks (and within a single task)
-should not conflict, or the results will be rather arbitrary.
-
-Packages that are only available on some architectures, or that may not
-be available on the user's installation media may still be listed. This 
-is no problem, they are simply ignored in those cases. Take care listing
-such packages as Key however.
-
-List only real packages, not virtual packages.
-
 Users are given the opportunity to drill down and select/unselect
 individual packages; the tasks they select only serve as a starting
 point. So err on the side of listing too many packages, rather than too
@@ -74,13 +42,7 @@ few (but don't go overboard, since many users will not bother with
 package-level selection at first).
 
 Keep short descriptions short -- very short -- and to the point. Do not
-include details about what individual packages a task includes, tasksel
-will do that for you.
-
-If a task is important enough that it should go near the top of its
-section, give it a relevance of 9 or 10. If a task is not likely to be
-used, give it a relevance of 1. Default is 5. (Low relevance tasks are also
-candidates for removal..)
+include details about what individual packages a task includes.
 
 Debian developers aside from the tasksel maintenance team may take over
 maintenance of tasks. Talk with the tasksel developers first, and then put

tasksel.pl

@@ -10,6 +10,7 @@ textdomain('tasksel');
 
 my $debconf_helper="/usr/lib/tasksel/tasksel-debconf";
 my $testdir="/usr/lib/tasksel/tests";
+my $packagesdir="/usr/lib/tasksel/packages";
 my $descdir="/usr/share/tasksel";
 
 sub warning {
@@ -70,21 +71,42 @@ sub read_task_desc {
 	return @ret;
 }
 
-# Given a task name, returns a list of all available packages in the task.
+sub all_tasks {
+	map { read_task_desc($_) } list_task_descs();
+}
+
+# Given task hash, returns a list of all available packages in the task.
+# If the aptitude_tasks parameter is true, then it does not expand tasks
+# that aptitude knows about, and just returns aptitude task syntax for
+# those.
 sub task_packages {
 	my $task=shift;
+	my $aptitude_tasks=shift;
+	
 	my @list;
-	local $/="\n\n";
-	open (AVAIL, "apt-cache dumpavail|");
-	while (<AVAIL>) {
-		if (/^Task: (.*)/m) {
-			my @tasks=split(", ", $1);
-			if (grep { $_ eq $task } @tasks) { 
-				push @list, $1 if /^Package: (.*)/m;
+	if ($task->{packages} eq 'task-fields') {
+		# task-fields method one is built-in for speed.
+		if ($aptitude_tasks) {
+			return "~t".$task->{task};
+		}
+		else {
+			local $/="\n\n";
+			open (AVAIL, "apt-cache dumpavail|");
+			while (<AVAIL>) {
+				if (/^Task: (.*)/m) {
+					my @tasks=split(", ", $1);
+					if (grep { $_ eq $task->{task} } @tasks) { 
+						push @list, $1 if /^Package: (.*)/m;
+					}
+				}
 			}
+			close AVAIL;
 		}
 	}
-	close AVAIL;
+	else {
+		# external method
+		@list=split "\n", `$packagesdir/$task->{packages} $task->{task}`;
+	}
 	return @list;
 }
 
@@ -201,17 +223,10 @@ sub order_for_display {
 	} @_;
 }
 
-# Process command line options.
-sub getopts {
-	my %ret;
-	Getopt::Long::Configure ("bundling");
-	if (! GetOptions(\%ret, "test|t", "required|r", "important|i", 
-		   "standard|s", "no-ui|n", "new-install", "list-tasks",
-		   "task-packages=s@", "task-desc=s")) {
-		usage();
-		exit(1);
-	}
-	return %ret;
+# Given a set of tasks and a name, returns the one with that name.
+sub name_to_task {
+	my $name=shift;
+	return (grep { $_->{task} eq $name } @_)[0];
 }
 
 sub usage {
@@ -230,114 +245,138 @@ tasksel [options]; where options is any combination of:
 });
 }
 
-my @aptitude_install;
-my @tasks_to_install;
-my %options=getopts();
-
-if (@ARGV) {
-	if ($ARGV[0] eq "install") {
-		shift;
-		push @aptitude_install, map { "~t$_" } @ARGV;
+# Process command line options and return them in a hash.
+sub getopts {
+	my %ret;
+	Getopt::Long::Configure ("bundling");
+	if (! GetOptions(\%ret, "test|t", "required|r", "important|i", 
+		   "standard|s", "no-ui|n", "new-install", "list-tasks",
+		   "task-packages=s@", "task-desc=s")) {
+		usage();
+		exit(1);
 	}
-	else {
+	# Special case apt-like syntax.
+	if (@ARGV && $ARGV[0] eq "install") {
+		shift @ARGV;
+		$ret{install} = shift @ARGV;
+	}
+	if (@ARGV) {
 		usage();
 		exit 1;
 	}
+	return %ret;
 }
 
-if (exists $options{"task-packages"}) {
-	foreach (@{$options{"task-packages"}}) {
-		print "$_\n" foreach task_packages($_);
-	}
-	exit(0);
-}
-elsif ($options{"task-desc"}) {
-	my $task=(grep { $_->{task} eq $options{"task-desc"} }
-			map { read_task_desc($_) } list_task_descs())[0];
-	if ($task) {
-		print dgettext("debian-tasks", join(" ",
-			@{$task->{description}}[1..$#{$task->{description}}]))."\n";
+sub main {
+	my %options=getopts();
+
+	# Options that output stuff and don't need a full processed list of tasks.
+	if (exists $options{"task-packages"}) {
+		my @tasks=all_tasks();
+		foreach my $taskname (@{$options{"task-packages"}}) {
+			print "$_\n" foreach task_packages(grep { $_->{task} eq $taskname } @tasks);
+		}
 		exit(0);
 	}
-	else {
-		exit(1);
+	elsif ($options{"task-desc"}) {
+		my $task=name_to_task($options{"task-desc"}, all_tasks());
+		if ($task) {
+			print dgettext("debian-tasks", join(" ",
+				@{$task->{description}}[1..$#{$task->{description}}]))."\n";
+			exit(0);
+		}
+		else {
+			exit(1);
+		}
 	}
-}
-
-my @tasks=map { hide_dependent_tasks($_) } map { task_test($_) }
-          grep { task_avail($_) } map { read_task_desc($_) }
-	  list_task_descs();
 
-if ($options{"list-tasks"}) {
-	print $_->{task}."\t".$_->{shortdesc}."\n"
-		foreach order_for_display(grep { $_->{_display} } @tasks);
-	exit(0);
-}
-
-if (! $options{"new-install"}) {
-	# Don't install hidden tasks if this is not a new install.
-	map { $_->{_install} = 0 } grep { $_->{_display} == 0 } @tasks;
-}
-if ($options{"required"}) {
-	push @aptitude_install, "~prequired";
-}
-if ($options{"important"}) {
-	push @aptitude_install, "~pimportant";
-}
-if ($options{"standard"}) {
-	push @aptitude_install, "~pstandard";
-}
-
-my @list = order_for_display(grep { $_->{_display} == 1 } @tasks);
-map { $_->{_install} = 0 } @list; # don't install displayed tasks unless selected
-if (@list && ! $options{"no-ui"}) {
-	my $question="tasksel/tasks";
-	if ($options{"new-install"}) {
-		$question="tasksel/first";
+	# This is relatively expensive, get the full list of available tasks and
+	# mark them.
+	my @tasks=map { hide_dependent_tasks($_) } map { task_test($_) }
+	          grep { task_avail($_) } all_tasks();
+	
+	if ($options{"list-tasks"}) {
+		print $_->{task}."\t".$_->{shortdesc}."\n"
+			foreach order_for_display(grep { $_->{_display} } @tasks);
+		exit(0);
 	}
-	my @default = grep { $_->{_display} == 1 && $_->{_install} == 1 } @tasks;
-	my $tmpfile=`tempfile`;
-	chomp $tmpfile;
-	system($debconf_helper, $tmpfile, task_to_debconf(@list),
-		task_to_debconf(@default), $question);
-	open(IN, "<$tmpfile");
-	my $ret=<IN>;
-	chomp $ret;
-	close IN;
-	unlink $tmpfile;
-	map { $_->{_install} = 1 } debconf_to_task($ret, @tasks);
-	if (! $options{test} && $ret=~/manual package selection/) {
-		# Doing better than this calls for a way to queue stuff for
-		# install in aptitude and then enter interactive mode.
-		my $ret=system("aptitude") >> 8;
-		if ($ret != 0) {
-			error gettext("aptitude failed");
+	
+	# Now work out what to tell aptitude to install.
+	my @aptitude_install;
+	if (! $options{"new-install"}) {
+		# Don't install hidden tasks if this is not a new install.
+		map { $_->{_install} = 0 } grep { $_->{_display} == 0 } @tasks;
+	}
+	if ($options{"required"}) {
+		push @aptitude_install, "~prequired";
+	}
+	if ($options{"important"}) {
+		push @aptitude_install, "~pimportant";
+	}
+	if ($options{"standard"}) {
+		push @aptitude_install, "~pstandard";
+	}
+	if ($options{"install"}) {
+		my $task=name_to_task($options{"install"}, @tasks);
+		$task->{_install} = 1 if $task;
+	}
+	
+	# The interactive bit.
+	my @list = order_for_display(grep { $_->{_display} == 1 } @tasks);
+	if (@list && ! $options{"no-ui"} && ! $options{install}) {
+		map { $_->{_install} = 0 } @list; # don't install displayed tasks unless selected
+		my $question="tasksel/tasks";
+		if ($options{"new-install"}) {
+			$question="tasksel/first";
+		}
+		my @default = grep { $_->{_display} == 1 && $_->{_install} == 1 } @tasks;
+		my $tmpfile=`tempfile`;
+		chomp $tmpfile;
+		system($debconf_helper, $tmpfile, task_to_debconf(@list),
+			task_to_debconf(@default), $question);
+		open(IN, "<$tmpfile");
+		my $ret=<IN>;
+		chomp $ret;
+		close IN;
+		unlink $tmpfile;
+		map { $_->{_install} = 1 } debconf_to_task($ret, @tasks);
+		if (! $options{test} && $ret=~/manual package selection/) {
+			# Doing better than this calls for a way to queue stuff for
+			# install in aptitude and then enter interactive mode.
+			my $ret=system("aptitude") >> 8;
+			if ($ret != 0) {
+				error gettext("aptitude failed");
+			}
 		}
 	}
-}
 
-# Mark dependnent packages for install if their dependencies are met.
-foreach my $task (@tasks) {
-	if (! $task->{_install} && exists $task->{depends} && length $task->{depends} ) {
-		$task->{_install} = 1;
-		foreach my $dep (split(', ', $task->{depends})) {
-			if (! grep { $_->{task} eq $dep && $_->{_install} } @tasks) {
-				$task->{_install} = 0;
+	# Mark dependnent packages for install if their dependencies are met.
+	foreach my $task (@tasks) {
+		if (! $task->{_install} && exists $task->{depends} && length $task->{depends} ) {
+			$task->{_install} = 1;
+			foreach my $dep (split(', ', $task->{depends})) {
+				if (! grep { $_->{task} eq $dep && $_->{_install} } @tasks) {
+					$task->{_install} = 0;
+				}
 			}
 		}
 	}
-}
 
-push @aptitude_install, map { "~t".$_->{task} } grep { $_->{_install} } @tasks;
+	# Add tasks to install.
+	push @aptitude_install, map { task_packages($_, 1) } grep { $_->{_install} } @tasks;
 
-if (@aptitude_install) {
-	if ($options{test}) {
-		print "aptitude --without-recommends -y install ".join(" ", @aptitude_install)."\n";
-	}
-	else {
-		my $ret=system("aptitude", "--without-recommends", "-y", "install", @aptitude_install) >> 8;
-		if ($ret != 0) {
-			error gettext("aptitude failed");
+	# And finally, act on selected tasks.
+	if (@aptitude_install) {
+		if ($options{test}) {
+			print "aptitude --without-recommends -y install ".join(" ", @aptitude_install)."\n";
+		}
+		else {
+			my $ret=system("aptitude", "--without-recommends", "-y", "install", @aptitude_install) >> 8;
+			if ($ret != 0) {
+				error gettext("aptitude failed");
+			}
 		}
 	}
 }
+
+main();

tasksel.pod

@@ -68,7 +68,8 @@ F</usr/share/tasksel/debian-tasks.desc>
 
 =head1 AUTHOR
 
-tasksel was written by Randolph Chung E<lt>tausq@debian.orgE<gt>.
+tasksel was written by Randolph Chung E<lt>tausq@debian.orgE<gt>
+and Joey Hess E<lt>joeyh@debiam.orgE<gt>
 
 =head1 HISTORY