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Debian Menu System


Abstract

The menu package was inspired by the install-fvwm2-menu program from the old fvwm2 package. However, menu tries to provide a more general interface for menu building. With the update-menus command from this package, no package needs to be modified for every X window manager again, and it provides a unified interface for both text- and X-oriented programs.


Copyright Notice

Copyright ©1997 Joost Witteveen, Joey Hess, Christian Schwarz. ©2002-2005 Bill Allombert.

This manual is free software; you may redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version.

This is distributed in the hope that it will be useful, but without any warranty; without even the implied warranty of merchantability or fitness for a particular purpose. See the GNU General Public License for more details.

A copy of the GNU General Public License is available as /usr/share/common-licenses/GPL in the Debian GNU/Linux distribution or on the World Wide Web at http://www.gnu.org/copyleft/gpl.html. You can also obtain it by writing to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA


Contents


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Debian Menu System
Chapter 1 - Introduction


Before the advent of update-menus, when the sysadmin installed a package onto a Debian system, they would need to edit various window manager config files to make the new program show up on, for example, fvwm's menus. The menus could easily become out of sync with what programs were actually available, with some menu items that didn't work, and other programs that lacked a menu entry. update-menus and Debian's menu package aim to solve this problem.

update-menus automatically generates menus of installed programs for window managers and other menu programs. It should be run whenever a menu file or menu-method file is changed. update-menus will be ran automatically when Debian packages that contain menu files are installed or removed from the system. Users themselves can add/delete menu items, and should then run update-menus as that user, thus creating window-manager startup files that are used in preference to the systemwide files.

One problem we ran into with menu-1.x (and before) was that the number of entries in any submenu vary wildly: on my system there are only two entries in /Applications/Editors, while I'm sure that other people have more like 20 entries there. Many people complained about the fullness of certain submenus, citing scientific studies or personal experience to explain why overfull or underfull submenus are a bad thing. To overcome this, menu-2.0 now can optimize the tree itself, possibly subdividing for example the /Applications/Editors tree in, say Editors/Beginner, Editors/Experienced, or whatever, if there are many entries in that submenu, or maybe even totally removing /Applications/Editors on systems where there are few editors installed. To be able to do this, menu follows the information supplied to it in the `hints' variables (see paragraph below, or the hints chapter).

Each package that needs to add an entry to the menu tree, includes a menu file /usr/share/menu/package-name. In this file, it will have one line per menu entry, like this (copied from /usr/share/menu/xbase):

        ?package(xbase):command="/usr/bin/xedit" needs="X11" \
                     section="Applications/Editors" title="Xedit" \
                     hints="Beginner,Small"

This describes the type of interface Xedit needs (X11), the menu section the menu entry should be in, the menu text, and the command that should be executed. Also, it tells menu that, if /Applications/Editors is overfull, it could put Xedit in a Applications/Editors/Beginner or Applications/Editors/Small subsection.

Whenever root runs update-menus, it will check all menu files in /etc/menu, /usr/lib/menu, /usr/share/menu, and run the installation scripts that display managers like fvwm2 should provide in /etc/menu-methods.

The menu package itself provides a set of default menu files, for people to get the idea, and to speed up things a bit. (These files should be incorporated into the package.)

Note, that substantial and incompatible changes took place with the menu-1.0 release, while substantial features were added by the release of menu-2.0. This document describes menu-2.0. Menu-2.0 now doesn't accept the menu-methods written for menu-0.x, but for most window managers that still have those old menu-methods, I have put new style menu-methods in /usr/share/doc/menu/examples. Everything written for menu-1.0 will work with menu-2.0.

Most notable changes between menu-0.x and menu-1.x are listed in the file README.changes in the menu package, the features added by menu-2.0 can be summarised here: hints, and the menu-2 compat mode. (where lines are finished by a ';' instead of a newline).


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Debian Menu System
Chapter 2 - Menu from the viewpoint of a user



2.1 How/when do the window manager startup files get created?

Basically, users don't need to know any of how and when the startup files are created, but they might be interested to know anyway.

When a package that wants to add something to the menu tree gets installed, it will run update-menus in its postinst script. Update-menus then reads in all menu files in /etc/menu/, /usr/lib/menu, /usr/share/menu and /usr/share/menu/default, and stores the menu entries of all installed packages in memory. Once that has been done, it will run the menu-methods in /etc/menu-methods/*, and pipe the information about the menu entries to the menu-methods on stdout, so that the menu-methods can read this. Each window-manager or other program that wants to have the Debian menu tree, will supply a menu-method script in /etc/menu-methods/. This menu-method then knows how to generate the startup-file for that window manager. To facilitate this task for the window-manager maintainers, menu provides a install-menu program. This program can generate the startupfiles for just about every window manager.


2.2 Tuning of the generated window manager startup files

In principle this is a very window-manager specific business. But for all window managers (and others) applies:

The file to attack is the menu-method in /etc/menu-methods/$wm, with $wm the name of your window manager. However, if this menu-method !include-s the menu.h file (as it should), you can also edit that file, to make your changes work for every installed window manager.

If the menu-method file of your window manager does !include the menu.h file, and makes proper use of the definitions in there, then you can look at the comments in that menu.h file to see how you can make minor adjustments to the look of your menus in your window manager.

To generally change the menu tree, see the next section.


2.3 Optimization of menu tree: hints

If hint_optimize=true has been set in a menu-method script (actually, that definition should appear in the !include-ed menu.h file), then install-menu will try to alter the menu tree, to make every submenu have about the optimum number of menu entries (as specified by hints_nentry=...). It will do that by removing under-full submenus (only if the `parent' of that submenu isn't itself already overfull), and by possibly creating new submenus, using hints. Note, however, that the optimization of the tree takes in principle exponential time, so menu speeds up the process, at the expense of occasionally not finding the best tree. So, the tree you are presented with may not be optimal. For tuning variables, see the hint_* variables in the last chapter.


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Debian Menu System
Chapter 3 - The menu file



3.1 Location

Packages-provided menu files should be in /usr/share/menu/, unless the menu files are actually executable binaries, in which case they go in /usr/lib/menu/. System-local menu files should be in /etc/menu/. User-specific menu files should be in ~/.menu/


3.2 Syntax

The format is:

     ?package(package[,package2,...]): \
        field1="value1"\
        field2="value2"\

Here is an example to describe the syntax of such a file:

     ?package(gnumeric):\             specifies what packages need to be installed
                                      multiple requirements should be separated by
                                      comma
       needs="X11"\                   what kind of environment this command expects
       section="Applications/Office"\ in what section this menu entry should be
       title="Gnumeric"\              the title of the menu entry
       command="gnumeric" \           the command to run
       hints="Gnome,Spreadsheets" \   some hints about menu placement.
       icon="/usr/share/pixmaps/gnumeric.xpm"  the path to the icon to use.

A number sign ("#") can be used to include comments. An entry must be terminated by a newline; however you can use a backslash to escape a newline.

Values must be quoted with ", and meta-characters (", backslash, newline) must be escaped with a backslash.

You can include several entries in the same file.

The file must be encoded in 7-bit ASCII. This is necessary to accomodate window managers that do not support 8-bit encodings. However the translations are not limited in encoding.

?package(...) contains a comma-separated list of packages that need to be installed for the menu entry to be displayed. That should include the package containing the menu file and any packages necessary to run the command not depended on by the package nor essential. Users can use pseudo-package names starting with "local." which are assumed to be always installed.

The fields needs, section, title and command are mandatory. Other fields are optional. Custom fields are supported, so you can add new fields for you own purpose. If a field is specified multiple times in a menu entry, the last instance will be used.


3.3 The title field

The title must follow the following requirements:

  1. It must be short. There is an optional longtitle field for users that want longer titles.

  1. It must be properly capitalized. Use Emacs and not emacs.

  1. It must be unique. Two entries must not have the same title.


3.4 The needs field

The following needs are documented for use in the Debian menu.

  1. X11: if this program runs under X11.

  1. text: if it runs under a terminal. X11 window managers will spawn an X terminal emulator.

  1. vc: if it runs under a linux virtual console but not under a X terminal emulator.

  1. wm: if it is a X11 window manager. The current window manager will exec(2) this program to avoid "Another window manager is running" errors.

A menu manager can use a special needs value reflecting the menu manager name for menu entries that must only be displayed in this menu manager. Examples include fvwm modules, dwww menu entries.

A program like gnuplot which can be run on X11 as well as on a text terminal should not have an extra entry with needs=X11 with an hard-coded call to an X terminal emulator, because this would defeat the configuration mechanism of menu that allow to choose which window manager is called.

On the other hand, if a program (like emacs) can be run as real X application as well as in a terminal, two entries should be listed, otherwise the program will always be run in an xterm (or rxvt). However, two entries are not allowed to have the same title. The title must be unique.


3.5 The section field

The section field holds a slash-separated list of hierarchical sections components.

The authoritative list of Debian's menu structure is maintained in the Debian Menu sub-policy document which is part of the Debian Policy package. The current menu structure was drafted in 2006 by Linas Zvirblis with input from the debian-devel mailing list.

The menu structure below is included only for convenience and is not authoritative. If it disagrees with the structure in the Debian Menu sub-policy, please send a wishlist bug to the menu package.

Packages must be placed in leaf sections. Please do not put your packages into any other sections.

Applications

Normal applications

Accessibility

Tools to aid people with disabilities or for machines lacking usual input devices.

Examples: gok, yasr, dasher.

Amateur Radio

Anything relating to HAM radio.

Examples: baken, hamsoft, twlog

Data Management

Interactive database programs, collection managers, address books, bibliography tools, etc.

gaby, alexandria, mdbtools

Editors

Editors, other than office word processors, for text-based information.

Examples: ksubtile, nano, hexedit

Education

Educational and training softwares.

Examples: gtypist, gcompris, quiz

Emulators

Software that allows you to run non-native software or more than one OS at a time.

Examples: wine, dosemu, qemu

File Management

Tools for file management, archiving, searching, CD/DVD burning, backup, etc.

Examples: file-roller, mc, baobab

Graphics

2D and 3D graphics manipulation software.

Examples: gimp, inkscape, imagemagick

Mobile Devices

Software that allows you to interface with mobile devices (phones, PDAs, etc.).

Examples: kandy, gnokii, gnome-pilot

Network

Network related software. This is a three-level section, do not put entries directly here.

Communication

Mail, USENET news, chat, instant messaging, IP telephony, video conferencing software, etc.

Examples: xchat, gaim, mutt

File Transfer

File transfer software such as download managers, FTP clients, P2P clients, etc.

Examples: amule, gftp, d4x

Monitoring

Network monitoring software

Examples: gip, ettercap, iptstate

Web Browsing

Web browsers, tools for offline browsing, etc.

Examples: elinks, epiphany-browser, webhttrack

Web News

Web feed (RSS, Atom, etc.) and podcast aggregators.

Examples: akregator, kitty, liferea

Office

Office suites, word processors, spreadsheets, CRM, ERP, financial sofware, etc.

Examples: openoffice.org, tinyerp-client, gnucash

Programming

IDEs, debuggers, etc.

Examples: anjuta, gdb, eclipse

Project Management

Timetable managers, group task trackers, bug tracking software, etc.

Examples: planner, bugzilla, gnotime

Science

Scientific and engineering-related software.

Astronomy

Astronomy-related software.

Examples: celestia, spacechart, stellarium

Biology

Biology-related software.

Examples: arb, ncbi-tools-x11, seaview

Chemistry

Chemistry-related software.

Examples: chemtool, kalzium, xdrawchem

Data Analysis

Software designed for processing, extracting, and presenting generic scientific data.

Examples: fityk, ygraph, mn-fit

Electronics

Circuit design tools, simulators and assemblers for microprocessors, etc

Examples: geda, gnucap, tkgate

Engineering

CAD, UML tools, diagram-drawing and other engineering-related software.

Examples: tcm, dia, qcad

Geoscience

Geoscience-related software.

Examples: earth3d, qgis, therion

Mathematics

Mathematics-related software.

Examples: gcalctool, snappea, xeukleides

Medicine

Medicine-related software.

Examples: mssstest, gnumed-client, xmedcon

Physics

Physics-related software.

Examples: kxterm, ifrit, paw

Social

Social sciences-related software.

Examples: gnomesword, hanzim, bibletime

Shells

Various shells to be used inside a terminal emulator.

Examples: bash, ksh, zsh

Sound

Sound players, editors, and rippers/recorders.

Examples: beep-media-player, grip, audacity

System

System related software.

Administration

Administrative and system configuration utilities, also tools for personal user settings.

Examples: gnome-control-center, configure-debian, gksu

Hardware

Tools for manipulating specific hardware, especially non-standard laptop hardware.

Examples: toshutils, nvclock-gtk, nvtv

Language Environment

This section is reserved for language-env as a special case.

Monitoring

System information and monitoring tools, log viewers, etc.

Examples: top, hal-device-manager, gtkdiskfree

Package Management

Package managers and related tools.

Examples: aptitude, deborphan, smartpm

Security

Security, cryptography and privacy related software, antiviruses, tools to track and report bugs, etc.

Examples: gpgkeys, bastille, avscan

Terminal Emulators

Graphical terminal emulators.

Examples: xterm, gnome-terminal, rxvt

Text

Text oriented tools like dictionaries, OCR, translation, text analysis software, etc.

Examples: kdrill, stardict, turkey

TV and Radio

TV-in, TV-out, FM radio, teletext browsers, etc.

Examples: gradio, gatos, alevt

Viewers

Software for viewing images, documents and other (non-video) media.

Examples: gqview, evince, gthumb

Video

Video players, editors, and rippers/recorders.

Examples: istanbul, totem, kino

Web Development

Software for web site editing, web programming, and site administration.

Examples: bluefish, screem, gphpedit

Games

Games and recreations

Action

Games that involve a lot of action and require fast reflexes.

Examples: xsoldier, supertux, xmoto

Adventure

Role playing and adventure games, interactive movies and stories, etc.

Examples: beneath-a-steel-sky, egoboo, kq

Blocks

Tetris-like games involving falling blocks.

Examples: crack-attack, frozen-bubble, netris

Board

Games played on a board.

Examples: phalanx, xshogi, xboard

Card

Games involving a deck of cards.

Examples: pysol, ace-of-penguins, xpat2

Puzzles

Tests of ingenuity and logic.

Examples: xmpuzzles, sgt-puzzles, enigma

Simulation

Simulations of the real world in all detail and complexity.

Examples: flightgear, torcs

Strategy

Games involving long-term strategic thinking.

Examples: wesnoth, widelands, netpanzer

Tools

Server browsers, configurators, editors, and other game-related tools that are not games themselves.

Examples: xqf, crystalspace

Toys

Amusements, eye-candy, entertaining demos, screen hacks (screensavers), etc.

Examples: xdesktopwaves, xphoon, xpenguins

Help

programs that provide user documentation

Examples: debian-reference, apt-howto, dhelp

Screen

Programs that affect the whole screen.

Saving

Tools for blanking the screen. Entries of screen hacks and configuration GUIs should go to other appropriate sections.

Examples: xscreensaver, xlockmore

Locking

Tools for locking the screen.

Examples: xscreensaver, xlockmore

Window Managers

X window managers.

Examples: fluxbox, metacity, waimea

FVWM Modules

FVWM-based window manager modules. As only modules related to the running window-manager are displayed, do not create subsections for specific window-managers.

Examples: fvwm, fvwm-gnome, fvwm95

Window Maker

This section is reserved for wmaker as a special case.

All wmaker specific entries must go here.

Users wanting to access some menu entries quickly can also put them in the root menu. This is done by using section="/". Package-provided menu entries must never use this feature.


3.6 The command field

The command field holds the command that should be executed when the menu entry is selected. Commands will be executed with sh -c using

     execl("/bin/sh","sh","-c",command)

or the equivalent.


3.7 The icon field

Please make sure the icons you specify are always available on the system. So, if you want to have an icon with your menu entry, the preferred method is to supply the icon with that package. Icons sould generally be installed in the directory /usr/share/pixmaps.

Debian package maintainers should ensure that any icons they include for use in the Debian menus conform to the following points:

  1. The icons should be in xpm format.

  1. The icons may not be larger than 32x32 pixels, although smaller sizes are ok.

  1. The background area of the icon should be transparent, if possible.

You can provide both 16x16 and 32x32 pixels icons using the variables icon16x16 and icon32x32 so that the user can configure menu to use one or the other.

If you, as a system administrator, don't like the icons in the menus, simply change the icon() function from the file /etc/menu-methods/menu.h, and run update-menus.


3.8 The hints field

Hints are used to help menu structure generated menus in a more optimal way. For example:

     ?package(emacs20):\
       needs="x11"\
       hints="Big,Expert,Featureful" \
       section="Applications/Editors"\
       title="Emacs 20"\
       command="/usr/bin/emacs20"\
       icon=/usr/share/emacs/20.3/etc/emacs.xbm

The above hints will tell menu to consider grouping emacs together with other editors that are marked similar. For example, if vi on your system has a hints="Small,Expert" definition, and there are too many entries in the /Applications/Editors menu entry, then menu will consider creating a /Applications/Editors/Expert submenu, and put both vi and emacs in it. (Of course, only if you have hint_optimize=true in your /etc/menu-methods/menu.h file).


3.9 Entries for menu sections.

It is possible to add entries for menu sections, but it is not mandatory since section entries are created automatically. However, this allows to specify fields for sections like icon and sort. The syntax for menu sections entries is the same as for regular entries, the section field holding the name of the parent section. For example

     ?package(local.games): needs="text" title="Games" section="/" sort="001"

will sort Games first.


3.10 Fvwm's task and title bars

The problem with the stuff in the task bar is that all items are displayed all of the time. So, if 1500 Debian packages all were to register a button, the buttons would quickly fill the screen, making the exercise useless. The few applications that are considered important enough to be listed in the task bar usually vary widely on each system, making it impossible to select a ``happy few'' apps that are allowed there on every Debian system. If you (as a local system administrator) want your fvwm2 to have a few buttons, you can install files for those packages in /menu/$package, containing a menu entry like this:

       ?Package(xmball):needs=button\
                     section=Games/Puzzles\
                     icon=path-to-pixmap.xpm\
                     title="Xmball"\
                     command=/usr/games/xmball

Then, do the following:

       cd /etc/menu-methods/
       cp fvwm2 fvwm2button
       vi fvwm2button

and remove all the "supported" entries, adding the one below. For the rest, leave everything the same except those listed below.

       supported 
         button="+ Style \"" $title "\" TitleIcon" $icon " Exec "  $command "\n"
       endsupported
       startmenu:   "AddToTitlebar \n"
       endmenu:     "\n"
       submenutitle:""
       mainmenu:
       genmenu:   "buttondefs.hook"

(Of course regular users (not system administrators) can also specify `buttonfiles' in their ~/.menu/ directory).


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Debian Menu System
Chapter 4 - What packages with applications should do


4.1 Providing a menu file

A package should provide a menu file /usr/share/menu/<package-name> that contains information about each program it likes to make available in the menus.


4.2 Adding a hook for dpkg in your packages

The postinst script and the postrm script of the package should include the line

      if test -x /usr/bin/update-menus; then update-menus; fi

If you are using debhelper, the program dh_installmenu can do it for you.


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Debian Menu System
Chapter 5 - What packages with menu managers should do


Each package containing a menu manager (i.e., a program that can display a menu) should provide a script or program in /etc/menu-methods/ that can read the menu files. This script will be executed by update-menus, which will feed the menu entries to be installed to your script via standard input (stdin).

The scripts in /etc/menu-methods/ should be configuration files, so the user can tune the behaviour of the script, and they must always include the /etc/menu-methods/menu.h configuration file at the beginning with the command !include menu.h For the same reason, scripts in /etc/menu-methods/ are requested to use the following configurable functions: title() for the title (in place of $title), icon() for the icon (in place of $icon), term() for running text command under X11. sections_translations() for the list of translations of sections name available. This later one is only defined if you !include lang.h

Good examples for these scripts for nearly all Debian window managers are included in the menu package in /usr/share/doc/menu/examples. Note that while working on your script, you can use the tricks described in "The internals of the menu package", section "The update-menus program", to run just your script, instead of having update-menus run all scripts (can save quite a lot of time).

This script should not be executable in the package. Instead the postinst should add the execute bit and then run update-menus (if it is executable).

Similarly, the postrm script when called with option ``remove'' should remove the execute bit and run update-menus (if it is executable).

Here is an example of such a postrm script using sh:

       #!/bin/sh
       set -e
       inst=/etc/menu-methods/#PACKAGE#
       case "$1" in
          remove)
             if [ -f $inst ]; then
                     chmod a-x $inst
                     if [ -x /usr/bin/update-menus ]; then update-menus ; fi
             fi
          ;;
          purge)
              #remove the files that install-menu creates:
              rm -rf /var/lib/foo-wm/menu
          ;;
          upgrade);;
          *)
              echo "postrm called with unknown argument \`$1'" >&2
              exit 0
          ;;
       esac

And here is a good example for a postinst script:

       #!/bin/sh
       set -e
       inst=/etc/menu-methods/#PACKAGE#
       if [ -f $inst ]; then
           chmod a+x $inst
           if [ -x /usr/bin/update-menus ]; then
               update-menus
           fi
       fi

If you are using debhelper, the program dh_installmenu can help you do it.

Please, do not make your package depend on the menu package! The preferred way of telling dpkg that your wm can cooperate with menu is:

        Suggests: menu

Please only consider using "depends" if you feel providing reasonable defaults for systems without menu will make life very difficult for you.


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Debian Menu System
Chapter 6 - How a user can override the menus



6.1 Configuring the menus

Users can specify their own menu entries in the ~/.menu directory. The files can have an arbitrary file name as long as the new syntax for the menu entries is used. They should start with either

       ?package(installed-package):

or

       ?package(local.mystuff):

if it's something that isn't ``debian-officially'' installed. (Any ``package'' that starts with ``local.'' is considered installed.)

If users want to have their own menu methods, they should create a ~/.menu-methods directory and put all their menu methods in it. (If ~/.menu-methods exists, /etc/menu-methods will not be searched when a user runs update-menus).

A system administrator should place system-wide menu entries in /etc/menu (not in /usr/share/menu/package, since these files will probably be overwritten by a package upgrade).


6.2 Specifying that a menu entry should not be displayed

If a user wants to remove the entries of package from the system menu then this will do the trick:

       echo -n  > ~/.menu/package

The zero-size file will tell update-menus that the corresponding package should not have any menu entries listed. A system administrator can remove menu entries system-wide with

       echo -n  > /etc/menu/package

6.3 Including other files

Historical comment by Joost:

More out of curiosity than anything else, I recently read the KDE mailing list. In it I saw some discussion about how good the Debian menu system is (whow, thanks, guys!), but one person found a missing feature: s/he said you couldn't include other files in the user menu files. Well, actually, it was already possible, but not very well documented.

To include the contents of the file /usr/share/menu/somefile, add this to your menu file:

     !include /usr/share/menu/somefile

Apart from that, it is of course possible to make the menu entry file executable (chmod a+x ~/.menu/package), and do something like

     #!/bin/sh
     cat  /usr/share/menu/somefile
     sed -e  "/unwanted_entry/s/?package(/?package(notinstalled./" \
          /usr/share/menu/someotherfile

to get the same effect, with the added flexibility of being able to filter out unwanted lines.


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Debian Menu System
Chapter 7 - The internals of the menu package



7.1 The update-menus program

On startup, update-menus checks the file /var/run/update-menus.pid and the pid in it. If there's an update-menus process with that pid it kills it. If /var/lib/dpkg/lock exists, it checks to see if dpkg supports triggers. If so, it uses dpkg-trigger to trigger a real update-menus run later. Otherwise, it forks to background and returns control to dpkg. The background process checks the /var/lib/dpkg/lock file approx. every two second until the file's gone.

Once it's decided to run, whether in the background after dpkg exits, or in the foreground when used with a trigger-capable dpkg, update-menus reads the menu-entry files in the following directories: /etc/menu, /usr/lib/menu, /usr/share/menu, /usr/share/menu/default. (if a user runs update-menus, it will add ~/.menu to the front of that list). For every menu entry line in each file it checks if the corresponding package is installed. The menu entries of all packages marked as installed by dpkg are added together in one big buffer that is kept in memory (exception: executable menu entry files are executed, and stdout is placed in the buffer).

Once it's read all menu entry files, update-menus starts all executable scripts in /etc/menu-methods/, hands the scripts the previously created buffer via stdin. (If update-menus is run by a user, it will first try to run the scripts in ~/.menu-methods, and only if that directory doesn't exist, it will run the scripts in /etc/menu-methods).

Note that as an aid to debugging, one can use

     update-menus --stdout > /tmp/menu-stdin

and then view the file /tmp/menu-stdin to see exactly what update-menus handed the menu-methods on their stdin.

This may also be useful for people writing /etc/menu-method/* scripts: Running update-menus every time you changed something in the script may be quite time-consuming. So, it's much easier to run update-menus --stdout once, and then run

       /etc/menu-methods/mymethod < /tmp/menu-stdin

(and, if that also takes too long, just try editing /tmp/menu-stdin, and removing 90% or so of all entries)


7.2 The install-menu program

The files /etc/menu-methods/$wm are executable config files that start with the line

       #!/usr/bin/install-menu

and thus start that program, handing it the configuration file for the specific window manager in the first command line argument. This configuration consists of:

  1. the compatibility mode ("menu-1" or "menu-2").

  1. where the various files should be stored/read.

  1. what "needs" are supported, and what wrapper files should be used for each "type".

  1. how to remove the generated menu files.

See /usr/share/doc/menu/examples/ of the menu package for more comments.

Options to install-menu:

       --remove  Remove the menu files instead of generating them.
       --verbose Output outline of operations that are performed.

Some window managers don't support an `include'-like statement in their system.*rc files (like m4 or cpp preprocessing); they cannot read the menudefs.hook file generated by install-menu from their system.*rc config file. To still be able to use them, install-menu will copy the file $path/$examplercfile to $path/$rcfile (with $examplercfile and $rcfile defined in the install-menu config file, and $path either the $rootprefix or ${HOME}/$userprefix, depending on whether root or user executed the file.), and replace all occurrences of ``install-menu-defs'' with the $genmenu file it just generated.

As an example, consider the following: examplercfile=system.foo-wm-example, rcfile=system.foo-wm, genmenu=menudefs.hook and rootprefix=/var/lib/foo-wm/menu. Now, if install-menu gets run, it will first generate the file /var/lib/foo-wm/menu/menudefs.hook. Next, it will line-by-line read the file /var/lib/foo-wm/menu/system.foo-wm-example and copy its contents to /var/lib/foo-wm/menu/system.foo-wm, replacing every occurrence of the string install-menu-defs with the contents of the file /var/lib/foo-wm/menu/menudefs.hook.

To activate the file copying in this way, simply define the $examplercfile and $rcfile variables in the install-menu configuration file (for example, see /etc/menu-methods/fvwm), and make sure there is a $path/$examplercfile ($path being either $rootprefix, or $userprefix.)

If you are writing a menu method, you can use the following to make debugging it somewhat more easily:

  1. use update-menus --stdout > /tmp/menu-stdin to create a list of menu entries in /tmp/menu-stdin and then

  1. you can run just your menu-method with (if it's called wm):

           ./wm -v < /tmp/menu-stdin
    

7.3 The install-menu config script definitions

The menu-methods in /etc/menu-methods/* are basically made up of a lot of ``tag=string'' definitions, telling install-menu how to generate a system.${wm}rc script. This way you can tune the look of generated system.${wm}rc to your needs.

In the following, something like

       treewalk="c(m)"

means that the treewalk variable by default has the value "c(m)".

For examples of what these scripts can look like, see /usr/share/doc/menu/examples/*.

compat="menu-1"

Two mode are defined:

"menu-1"

menu directives are terminated by an end-of-line character.

"menu-2"

menu directives are terminated by a semicolon character.

This must be just after the !include "menu.h" directive so that menu.h can use its own compat mode.

outputencoding="UTF-8"

Set the encoding used for output files. Use iconv --list to get the list of supported encoding. Useful values include "UTF-8" and "ISO-8859-1". The special value "LOCALE" means that the current locale encoding will be used. If set to an empty string, no translations are performed. This is the default.

outputlanguage=""

If set to "C" automatic translations will be disabled. Note that you can still use translate() to perform explicit translation.

supported
endsupported

Between the supported and endsupported keywords you define what "needs" are supported by this window manager. So, the following is an example for a wm that supports both needs=x11 and needs=text:

       function q($s) = "\"" esc($s,"\\\"") "\""
       supported
         x11 =" ShowEntry(" q(title()) ", " q($command) ")"
         text=" ShowEntry(" q(title()) ", " q(term())   ")"
       endsupported

For the variable substitution (and functions, not shown above), see the next paragraph. In the above example, you'll notice that for the menu entries that "need=text", the term() function is used. This is a user-supplied function that will run $command in a X terminal emulator. Also, as X11 is higher up in the supported list above than text, a package that supplies both a "needs=X11" and a "needs=text" entry will have the needs=X11 entry installed, in favour of the needs=text entry. You can continue lines on the next line with a backslash ("\"), but make sure you don't add any spaces after the backslash.

startmenu=""
endmenu=""
submenutitle=""

These define what to print for the beginning/end of a menu, and how to the print a menu entry that pops up another menu. They are substituted the same way as the "supported" stuff is; see next paragraph.

treewalk="c(m)"

This string defines in what order to dump the $startmenu, $endmenu, and $submenutitle (and its children). Each char in the string refers to:

         c  : dump children of menu.
         m  : dump this menu's $submenutitles
         (  : dump $startmenu
         )  : dump $endmenu
         M  : dump all $submenutitles of this menu and this menu's children.

The default is "c(m)". For olvwm, one needs: "(M)"

genmenu=""

The menu file to generate (usually something like system."$wm"rc). The file itself may depend on the level or title that is currently being worked on, like

         genmenu="/subdir/" replacewith($section," ","_") "/rc.menu"

(Substitution works just like in the supported stuff, see above). Note that the files made this way are truncated upon opening, so if you have a genmenu like the example above, then your endmenu= will override the startmenu stuff (but you probably only need one of the two anyway).

rootsection="/Debian"

the prefix every $section variable gets.

prerun=""
postrun=""

The commands to run before and after, respectively, the actual generation of the menudefs.hook (genmenu) file. Commands will be executed by sh. Example:

       prerun="rm -rf " prefix() "/*"
       postrun="killall -USR1 fvwm2"

(Substitution works just like the supported stuff, see below).

preruntest=""

Just like prerun, but if the return value of the command is non-zero, menu will quit.

also_run=""

If non-zero, install-menus will, after generating the output files, also load the file also_run, and use the new assignments to treewalk, genmenu, etc. to generate more output. This second time, variables like prerun and all of the hint stuff are ignored.

removemenu=""

The command to run when the menu-method is invoked with the option --remove. This should remove all the autogenerated menu files. If this option is not present, then install menu will remove genmenu if it is a constant string and rcfile if it is defined, and try to remove prefix() if it is empty.

onlyrunasroot=false
onlyrunasuser=false

If onlyrunasroot is set to true, install-menu will quit silently when run as a user. Similarly for onlyrunasuser. onlyrunasroot is deprecated since it is simpler to just not define userprefix. On the other hand, onlyrunasuser might be needed if you use rcfile since rootprefix is used as a fallback location for the template.

preoutput="#Automatically generated file. Do not edit (see /usr/share/doc/menu/html)\n\n"
postoutput=""

Text to put at the beginning resp. end of the generated file ($genmenu).

command=""

A command to run instead of install-menus. This command used to be needed to get around limitations due to compatibility stuff. But that compatibility with pre menu-1 stuff has been dropped, and isn't needed any more.

Example:

       command="cat > /tmp/menu-stdin"
hotkeyexclude=""

Keys not to use for hotkey generation. You can use the same variables and functions here as in for example the startmenu sections.

Example:

       hotkeyexclude="q" $section
hotkeycase="insensitive"

can be either "insensitive" or "sensitive". Determines whether the hotkeys can be of mixed case (fvwm2 reads the hotkeys case-insensitive, pdmenu case-sensitive). In case of the titles "Xa" and "xb", hotkey case-insensitive will generate "X" and "b", whereas case-sensitive would generate "X" and "x".

sort=$sort ":" $title

Entries within one menu will be alphabetically sorted by whatever sort returns. So, if you do sort=ifelse($command, "1", "0"):$title, then all submenus will appear above the commands in a submenu. (A submenu always has $command=""). Or, as Joey Hess writes:

       You can add another field to the menu items, with whatever name you like,
       let's say it's called priority. Then add this line to
       /etc/menu-methods/*:
       
       sort=ifelse($priority, $priority, "9")
       
       This has the result of sorting things so items with a low priority sort to the
       top, and items with no priority default to priority 9 and sort to the bottom.
       
       (Note that it compares the strings alphabetically, not numerically.)
rcfile=""

If the window manager doesn't support an "include filename" or "read(filename)" statement in it's config file, you can rename the wm's config file to system."$wm"rc-menu, and insert a "install-menu-defs" line (without the quotes, or whitespace around it, and "install-menu-defs" must be the only thing on the line) in the system."$wm"rc-menu file. This will then get replaced by the $genmenu file that was just created (see also $examplercfile).

examplercfile=""

if needed (see rcfile), this is the system.rc"$wm"-menu file. In that case, make rcfile=system.rc"$wm".

rootprefix=""

The prefix to use when running as root (applies to $genmenu, $rcfile, $examplercfile and other old cache files). If it is not defined, the menu-method will be skipped when run as root.

userprefix=""

As rootprefix, but when running as user. userprefix is relative to the user home directory, unless it start with 2 slashes, in which case it is treated as an absolute path. If it is not defined, the menu-method will be skipped when run as a user.

hint_optimize=false

If set to true, menu will try to generate an `optimal' tree, using the variables below. If set to false, menu will keep the sections as they are specified in the menu entry files (and ignore any hint stuff).

hint_nentry=6

Optimal number of entries in a submenu. It's a float, so you can set it to 5.5 if you cannot decide between 5 and 6. Also, values less than 3 probably don't work very well at the moment.

hint_topnentry=5

Same as hint_nentry, but for the top level menu. Often here are other entries, added by the window-manager itself (like Exit, Xterm, whatever) that menu doesn't know about, so that you may want to instruct menu to put less entries in the top level menu.

hint_mixedpenalty=15.0

Penalty for `mixed' menus. Mixed menus are those with both submenus and direct commands in them.

hint_minhintfreq=0.1

Minimal relative frequency for the hints before they are considered. Internal variable to speed up the tree generation. If you find menu slow, increase this value (to, say 0.2 or 0.3).

hint_mlpenalty=2000

`max local penalty', while evaluating the possible trees, menu gives `penalties' for submenus that don't contain the desired number of submenus. The penalty is sqrt(n_entry_opt-n_entry), and eventually will be calculated as a sum of all nodes. But to speed things up, menu will discard possibilities in which any node has a `local' penalty of more than hint_mlpenalty. Increase this value if you think menu is overlooking your favorite tree (also decrease minhintfreq), decrease this value if you think menu is wasting too much time. Because of hint_max_ntry, the influence of this variable is nearly zero nowadays.

hint_max_ntry=4

menu will recursively, for each node, try the hint_max_ntry best local menu-divisions.

hints_max_iter_hint=5

The search for what hints to use in one menu is rather expensive. But due to the way things are sorted, menu seems to always find the `best' match in the first 2% of iterations. Thus, a way to speed things up is simply to cut of menu searching after `some' iterations are done. This value controls this, and limits the number of iterations to 5+hint_max_iter_hint*number_of_possible_hints. Set this value to negative to disable this.

hint_debug=false

Set to true if you want to see loads and loads of debug output.


7.4 Hints, tree optimization

The hints actually work in a rather strange way: when hint_optimize=true then all $section elements are added to the specified $hints variable, and the order (/Applications/Editors or /Editors/Applications) of the resulting hints is completely ignored. Then, the hints for each menu entry are handed to the optimization routine, which will calculate a reasonable tree for those hints. That tree must comply with the following:

When a user looks for a program "Program" with, say, hints "Good,Bulky,Heaven", then, while walking through the tree, it should at every node visited be clear for the user what submenu to select (or the menu should have "Program" directly in it). So, the top-level menu may look like

       Good
       Hell
       Microsoft

because then a searcher for a menu entry with hints "Good,Bulky,Heaven" will know to select the submenu "Good". The toplevel menu may not look like

       Good
       Hell
       Heaven

as now it isn't clear whether to visit the Good or the Heaven submenu.

That rule allows usually for many different trees, and the task of the optimization procedure is to select, in a finite amount of time, the tree that best matches the user's desire about the optimum number of menu entries.


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Debian Menu System
Chapter 8 - Variables and functions in the install-menu scripts


The supported "needs" definitions and "startmenu=", "endmenu=" and "submenutitle=" are interpreted as follows:


8.1 String constants

Anything inside double quotes ("") is interpreted as a string, and is written verbatim to the output file. Escape sequences like \n, \t, ... will be replaced with their C expansions (but currently \0xx octal escape sequences are not supported).


8.2 Variables

Anything matching $[a-z,A-Z,_]* is interpreted as a variable, and the corresponding definition from the menu entry is substituted.


8.2.1 Special variables

The following variables are treated in a special way by install-menus, either because they are used for other purposes too, or because they are modified by install-menus (the ones marked with a "!" are modified by install-menus).

needs:

Used to determine whether the window manager supports this menu entry.

command:

If this is undefined, this menu entry is taken as defining a sub-menu. This way you can specify icons of sub-menus.

title!:

Used for sorting (see section). For sub-menu entries (those with empty command), this is initialised to the last part of the section. Please, keep the title short (two words at maximum). The title is for people who already know what program they want to start. See "longtitle" and "description" below for longer descriptions.

sort:

Used for sorting (see section). To make sure an entry is at the beginning, use something with a low ASCII number, like "$". For sorting at the end, use "|"

section!:

Used to determine the section of the menu entry. The menu entries that have a empty $command, ie those that define a submenu, have $title added to the end of $section The menu entries that have a non-empty $command have their $section modified to $section/$title, or $section/$sort:$title if $sort is defined. The menu entries within one submenu are sorted according to $section. If you want to retrieve the real section name, see the $basesection variable.

basesection!:

Used to contain the *real* section name. This is useful because $section will be changed to $section/$title in special cases (see above). This causes a problem when you want to do parent($section) because you won't get the real parent section. Instead you can use $basesection, which will never contain the title.

hotkey!:

Modified to reflect what install-menus thinks is the most suitable hotkey for this menu entry. The hotkey= in the menu entry file is taken as a suggestion, that could be overwritten if there is another entry with the same hotkey=. To suggest two possible hotkeys for an entry use hotkey="ab", with "a" being the most preferred hotkey.


8.2.2 Preferred variables

The following aren't special for install-menus, but it's nice (read: essential) to use the same variables for the same things. So, I'll suggest some here. If you want to invent new ones, please do so and mail them to me so that I can include them here.

icon:

The location of the icon file for this menu entry. If you don't have an icon file, just leave out the icon= in the menu entry.

icon32x32:

The location of a 32x32 icon file for this menu entry.

icon16x16:

The location of a 16x16 icon file for this menu entry. This allows users to choose between 16x16 and 32x32 icon.

longtitle:

For people that like descriptive titles (about one line) It is probably best to include this in your menu entries, while the window-managers don't (by default) put it in the menus. That way, people who want descriptive titles can turn them on, but others don't need to use them.

description:

An even longer description (about 5 lines). For example, a description of the documentation in the dwww generated html pages.


8.2.3 Suggested variables

The following variables probably shouldn't appear often (or at all) in the menu files supplied with packages. They are mostly intended for use by local system managers. Nevertheless, it is advised that all Debian systems use the following variable names:

visible

Some apps add entries to utmp the utmp file, so that "who" and friends know they are running (this is especially true for xterms etc). If $visible set (to anything other than "" or "none"), xterms etc will not write logging info to utmp. (may not work for your window manager).

geometry

For X apps, this will be the size of the (main) window that will be created (units in either chars or pixels, depending on type of main window (xterm or graphic)). If you as package maintainer want to use this, you should probably think about setting this variable somewhere in an Xresources file.


8.3 Functions

Anything matching [a-zA-Z_]+ is taken as a function name, and an error is generated if the function doesn't exist. The arguments of the functions can be other functions, string constants or variables.

prefix()

returns the current prefix dir: either $rootprefix, or $HOME/$userprefix, depending on who runs install-menu

ifroot($rootarg, $userarg)

if(getuid()==0) print $rootarg, else print $userarg

print($arg)

Same as just $arg; if $arg is empty, generate an error.

nstring($n, $string)

write $string $n times. So, nstring(3,"Aa") writes "AaAaAa". (Useful in combination with level()).

esc($arg1,$arg2)

Print $arg1, but escape all occurrences of characters in $arg2 with a '\' (thus, if arg1="hello", arg2="lo", print "he\l\l\o").

escwith($arg1, $arg2, $arg3)

Same as esc, but use $arg3 as escape sequence.

escfirst($arg1, $arg2, $arg3)

Same as escwith, but only escapes first occurrence of $arg2.

cppesc($arg1)

Escape anything that isn't a letter, number or _ with $<hex-ascii-code>. So, for example, a '-' is replaced by '$2D'. This way, $arg1 can be used as a #define in cpp.

tolower($arg)
toupper($arg)

Returns the argument set in lowercases resp uppercases.

replacewith($s, $replace, $with)

Search $s for occurrences of characters from string replace, and replace them by the corresponding character in $with. Example: replacewith("hello $world, %dir", "$% ", "123") returns: "hello31world,32dir"

replace($s, $replace, $with)

Search $s for occurences of $replace and replace them with $with. Note that the behaviour of this function is quite different than the replacewith() function.

ifempty($arg1, $arg2)

If $arg1 is empty, print $arg2, otherwise print nothing. For compatibility, $arg1="none" is interpreted as empty.

ifnempty($arg1, $arg2)

If $arg1 is not empty, print $arg2. For compatibility, the string "none" is seen as empty.

ifelse($arg1,$arg2,$arg3)

If $arg1 is non-empty, print $arg2, otherwise $arg3. For compatibility, the string "none" is seen as empty.

ifeq($arg1, $arg2, $arg3)

If ($arg1==$arg2) then print $arg3

ifneq($arg1, $arg2, $arg3)

If ($arg1!=$arg2) then print $arg3

ifeqelse($arg1, $arg2, $arg3, $arg4)

If ($arg1==$arg2) then print $arg3 else print $arg4

cond_surr($arg1, $arg2, $arg3)

If $arg1 is non-empty print $arg2$arg1$arg3, otherwise print nothing. For compatibility, $arg1="none" is interpreted as empty.

iffile($arg1, $arg2)

If file $arg1 exists, and can be opened for reading by whoever started the current process, return $arg2, otherwise return nothing.

ifelsefile($arg1, $arg2, $arg3)

If file $arg1 exists, and can be opened for reading by whoever started the current process, return $arg2, otherwise return $arg3.

catfile($arg1)

Return the contents of file $arg1.

shell($arg1)

Return the output of the shell command $arg1.

forall($array, "var", $exec)

For each element of the column separated array $array, set $var to that element, and print $exec. Example:

           !include lang.h
           forall(sections_translations(), "lang", \ 
              " section[" $lang "]=" translate($lang, title()) "\n")
parent($arg)

for $arg a "directory", return parent directory: parent("/Debian/Applications/Editors") = "/Debian/Applications".

basename($arg)

return the last part of the parent directory: basename("/Debian/Applications/Editors") = "Applications".

stripdir($arg)

everything after the last slash, i.e. what basename() should have returned: stripdir("/Debian/Applications/Editors") = "Editors".

entrycount()

the number of entries in this menu.

entryindex()

returns relative position of this entry. Start with 0, last entry is entrycount() - 1. BUG: if sort= anything other than $title, then this entryindex() will return incorrect values.

firstentry($arg)

return $arg if this is the first entry of this menu (that is, entryindex() = 0). Else, return nothing.

lastentry()

return $arg if this is the last entry in this menu (that is, entryindex() = entrycount() -1). Else, return nothing.

level()

return nesting of this menu in the total menu tree.

add($arg1,$arg2)
sub($arg1,$arg2)
mult($arg1,$arg2)
div($arg1,$arg2)

returns the sum, difference, product or quotient of $arg1 and $arg2. Note that the arguments are strings, that are converted to integers. example: mult("24", entryindex())

rcfile()
examplercfile()
mainmenutitle()
rootsection()
rootprefix()
userprefix()
treewalk()
postoutput()
preoutput()

These functions all output whatever they were defined to be in the menu-method file.

translate($lang, $text)

Translate $text into $lang using gettext, see forall for an example. Note that currently outputlanguage must be set to "C". If $lang is the empty string, $text will be translated in the current locale language. See sections_translations() for a list of available translations.

implicit concatenation

String constants, variables and functions can be concatenated by placing them after each other with a space in between, like: "hello" ifelse($comma, $comma, " sorry" $period " comma not defined") " world"


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Debian Menu System

version 1.4, 24 January 2010

Joost Witteveen joostje@debian.org
Joey Hess joeyh@debian.org
Christian Schwarz schwarz@debian.org
Bill Allombert ballombe@debian.org