Typing glyphs on Linux: Difference between revisions

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Since mid-2012, most Linux distributions with [[wikipedia:X_Window_System|X11]] have [[Dyalog APL]] keyboard support included with the distribution,<ref>[[Dyalog]] [[Forums]]. [https://forums.dyalog.com/viewtopic.php?f=20&t=210 Keyboard setup on Linux]. Sep 21, 2010.</ref> using <source lang=console inline>xkb</source>, the [https://www.x.org/wiki/XKB/ X Keyboard Extension].<ref>[[Geoff Streeter]]. [https://www.dyalog.com/uploads/conference/dyalog10/presentations/P19_Streeter_Keyboards.pdf Supporting APL keyboards on Linux]. [[Dyalog '10]].</ref>
:''This article is specific for Linux. For Hardware and other platforms, see [[Typing glyphs]].''
 
Since mid-2012, most Linux distributions with [[wikipedia:X_Window_System|X11]] and [[wikipedia:Wayland_(display_server_protocol)|Wayland]] have [[Dyalog APL]] keyboard support included with the distribution,<ref>[[Dyalog]] [[Forums]]. [https://forums.dyalog.com/viewtopic.php?f=20&t=210 Keyboard setup on Linux]. Sep 21, 2010.</ref> using <syntaxhighlight lang=console inline>xkb</syntaxhighlight>, the [https://www.x.org/wiki/XKB/ X Keyboard Extension].<ref name="Dyalog APL XKB">[[Geoff Streeter]]. [https://www.dyalog.com/uploads/conference/dyalog10/presentations/P19_Streeter_Keyboards.pdf Supporting APL keyboards on Linux]. [[Dyalog '10]].</ref>


== setxkbmap ==
== setxkbmap ==


The simplest way to set up an APL keyboard on Linux is with the following <source lang=console inline>setxkbmap</source> command. Enter the following in your terminal emulator of choice:
The simplest way to set up an APL keyboard on Linux is with the following <syntaxhighlight lang=console inline>setxkbmap</syntaxhighlight> command. Enter the following in your terminal emulator of choice:


<source lang=console>
<syntaxhighlight lang=console>
setxkbmap -layout us,apl -variant ,dyalog -option grp:switch
setxkbmap -layout us,apl -variant ,dyalog -option grp:switch
</source>
</syntaxhighlight>


An explanation:
An explanation:


* <source lang=console inline>-layout us,apl</source> assigns <source lang=console inline>us</source> ([[wikipedia:American_English|U.S. English]]) to be the primary layout, whereas <source lang=console inline>apl</source> is secondary
* <syntaxhighlight lang=console inline>-layout us,apl</syntaxhighlight> assigns <syntaxhighlight lang=console inline>us</syntaxhighlight> ([[wikipedia:American_English|U.S. English]]) to be the primary layout, whereas <syntaxhighlight lang=console inline>apl</syntaxhighlight> is secondary


* <source lang=console inline>-option grp:switch</source> assigns <kbd>Right Alt</kbd> to switch to the secondary <source lang=console inline>apl</source> layout when it is pressed, otherwise <source lang=console inline>us</source> is used
* <syntaxhighlight lang=console inline>-option grp:switch</syntaxhighlight> assigns <kbd>Right Alt</kbd> to switch to the secondary <syntaxhighlight lang=console inline>apl</syntaxhighlight> layout when it is pressed, otherwise <syntaxhighlight lang=console inline>us</syntaxhighlight> is used


* <source lang=console inline>-variant ,dyalog</source> assigns the [[Dyalog APL]] variant to the <source lang=console inline>apl</source> layout which contains modifiations unique to the Dyalog language ('''Note the preceding comma''')
* <syntaxhighlight lang=console inline>-variant ,dyalog</syntaxhighlight> assigns the [[Dyalog APL]] variant to the <syntaxhighlight lang=console inline>apl</syntaxhighlight> layout which contains modifiations unique to the Dyalog language ('''Note the preceding comma''')


A full list of keys that can be used to switch layouts is included in <source lang=console inline>/usr/share/X11/xkb/rules/evdev.lst</source> under the <source lang=console inline>option</source> category.
A full list of keys that can be used to switch layouts is included in <syntaxhighlight lang=console inline>/usr/share/X11/xkb/rules/evdev.lst</syntaxhighlight> under the <syntaxhighlight lang=console inline>option</syntaxhighlight> category.


'''Notes:'''
Note:


* These changes are not permanent; the user will have to select one of a myriad of methods to run the command on startup. Alternatively, if they use one of the [[wikipedia:Desktop_environment|desktop environments]] listed below, they can follow those instructions.
* These changes are not permanent; the user will have to select one of a myriad of methods to run the command on startup. Alternatively, if they use one of the [[wikipedia:Desktop_environment|desktop environments]] listed below, they can follow those instructions.


* If you want to specify a different language, say for United Kingdom, specify "gb" instead "us" (_not_ "uk"!)
* If you want to specify a different language, say for United Kingdom, specify <syntaxhighlight lang=console inline>gb</syntaxhighlight> instead of <syntaxhighlight lang=console inline>us</syntaxhighlight> (not <syntaxhighlight lang=console inline>uk</syntaxhighlight>)
 
* If you want to specify a different layout, dvorak, bepo, etc, change the variant flag to <syntaxhighlight lang=console inline>dvorak,dyalog</syntaxhighlight>.
 
== libinput ==
 
X11 and Wayland use XKB rules to determine their layout. To set a layout create a file called <syntaxhighlight lang=console inline>00-keyboard.conf</syntaxhighlight> at <syntaxhighlight lang=console inline>/etc/X11/xorg.conf.d</syntaxhighlight> or <syntaxhighlight lang=console inline>/usr/etc/X11/corg.conf.d</syntaxhighlight>, ensuring you have permissions, and edit it to:
 
<syntaxhighlight lang=console>
Section "InputClass"
        Identifier "system-keyboard"
        MatchIsKeyboard "on"
        Option "XkbLayout" "us,apl"
        Option "XkbVariant" ",dyalog"
        Option "XkbOptions" "grp:switch"
EndSection
</syntaxhighlight>
 
The options "us,apl", ",dyalog", and "grp:switch" are the same as in [[#setxkbmap|setxkbmap]] and can be changed to better suit your environment.
 
Once saved this will affect any future session. To change the current session and test out layouts, use <syntaxhighlight lang=console inline>setxkbmap</syntaxhighlight>.


== GNOME ==
== GNOME ==
Line 37: Line 59:


# Navigate to <code>~/.config/autostart</code> and create a <code>.desktop</code> with any name that will help you remember its function.
# Navigate to <code>~/.config/autostart</code> and create a <code>.desktop</code> with any name that will help you remember its function.
# Add the following to the contents of your file, customizing to suit your needs:<source lang=ini>
# Add the following to the contents of your file, customizing to suit your needs:<syntaxhighlight lang=ini>
[Desktop Entry]
[Desktop Entry]
Type=Application
Type=Application
Line 48: Line 70:
Comment[en_US]=
Comment[en_US]=
Comment=
Comment=
</source>
</syntaxhighlight>


== LXDE ==
== LXDE ==


# Prepend an <source lang=console inline>@</source> to the <source lang=console inline>setxkbmap</source> command from above:<br><source lang=console>
# Prepend an <syntaxhighlight lang=console inline>@</syntaxhighlight> to the <syntaxhighlight lang=console inline>setxkbmap</syntaxhighlight> command from above:<br><syntaxhighlight lang=console>
@setxkbmap -layout us,apl -variant ,dyalog -option grp:switch
@setxkbmap -layout us,apl -variant ,dyalog -option grp:switch
</source>
</syntaxhighlight>
# Add it as a line in your user's LXDE <source lang=console inline>autostart</source> file, located at:<br><source lang=console>
# Add it as a line in your user's LXDE <syntaxhighlight lang=console inline>autostart</syntaxhighlight> file, located at:<br><syntaxhighlight lang=console>
~/.config/lxsession/LXDE/autostart
~/.config/lxsession/LXDE/autostart
</source>
</syntaxhighlight>


For Lubuntu versions up to and including 18.04 (before the LXQt split), the location of <source lang=console inline>autostart</source> is <source lang=console inline>~/.config/lxsession/Lubuntu/autostart</source>.
For Lubuntu versions up to and including 18.04 (before the LXQt split), the location of <syntaxhighlight lang=console inline>autostart</syntaxhighlight> is <syntaxhighlight lang=console inline>~/.config/lxsession/Lubuntu/autostart</syntaxhighlight>.


== LXQt ==
== LXQt ==
Line 65: Line 87:
=== GUI ===
=== GUI ===


# From your LXQt panel, navigate to ''Preferences'' → ''LXQt Settings'' → ''Session Settings''; alternatively, enter <source lang=console inline>lxqt-config-session</source> in your terminal emulator. You will be greeted with the following window:<br>[[File:Lxqt-session-settings.png|frameless|LXQt Autostart menu of Session Settings window]]
# From your LXQt panel, navigate to ''Preferences'' → ''LXQt Settings'' → ''Session Settings''; alternatively, enter <syntaxhighlight lang=console inline>lxqt-config-session</syntaxhighlight> in your terminal emulator. You will be greeted with the following window:<br>[[File:Lxqt-session-settings.png|frameless|LXQt Autostart menu of Session Settings window]]
# Select the <source lang=console inline>LXQt Autostart</source> dropdown (it will be highlighted as shown above) and click the <kbd>Add</kbd> button to display the following pop-up window:<br>[[File:Lxqt-add-autostart.png|frameless|LXQt add a new autostart menu item]]
# Select the <syntaxhighlight lang=console inline>LXQt Autostart</syntaxhighlight> dropdown (it will be highlighted as shown above) and click the <kbd>Add</kbd> button to display the following pop-up window:<br>[[File:Lxqt-add-autostart.png|frameless|LXQt add a new autostart menu item]]
# Provide a name, enter your <code>setxkbmap</code> command, and click <kbd>OK</kbd> when finished.
# Provide a name, enter your <code>setxkbmap</code> command, and click <kbd>OK</kbd> when finished.


=== Terminal ===
=== Terminal ===


The above GUI approach merely creates a <source lang=console inline>.desktop</source> file in the user's <source lang=console inline>~/.config/autostart</source>. Create your own file in the <source lang=console inline>autostart</source> directory whose contents are as follows, to replicate the functionality achieved through the GUI:
The above GUI approach merely creates a <syntaxhighlight lang=console inline>.desktop</syntaxhighlight> file in the user's <syntaxhighlight lang=console inline>~/.config/autostart</syntaxhighlight>. Create your own file in the <syntaxhighlight lang=console inline>autostart</syntaxhighlight> directory whose contents are as follows, to replicate the functionality achieved through the GUI:


<source lang=ini>
<syntaxhighlight lang=ini>
[Desktop Entry]
[Desktop Entry]
Exec=setxkbmap -layout us,apl -variant ,dyalog -option grp:switch
Exec=setxkbmap -layout us,apl -variant ,dyalog -option grp:switch
Line 80: Line 102:
Type=Application
Type=Application
Version=1.0
Version=1.0
</source>
</syntaxhighlight>


== MATE ==
== MATE ==
Line 97: Line 119:
Add the following to the contents of your file, customizing to suit your needs:
Add the following to the contents of your file, customizing to suit your needs:


<source lang=ini>
<syntaxhighlight lang=ini>
[Desktop Entry]
[Desktop Entry]
Type=Application
Type=Application
Line 108: Line 130:
Comment=
Comment=
X-MATE-Autostart-Delay=0
X-MATE-Autostart-Delay=0
</source>
</syntaxhighlight>


== Wayland ==
== Wayland ==
Line 133: Line 155:
Xfce ships with a utility, [https://docs.xfce.org/xfce/xfconf/xfconf-query xfconf-query], which allows you to manage Xfce's XML configuration files on the command line. Enter the following commands into your terminal:
Xfce ships with a utility, [https://docs.xfce.org/xfce/xfconf/xfconf-query xfconf-query], which allows you to manage Xfce's XML configuration files on the command line. Enter the following commands into your terminal:


<source lang=console>
<syntaxhighlight lang=console>
xfconf-query -c keyboard-layout -n -p '/Default/XkbDisable' -t 'bool' -s 'false'
xfconf-query -c keyboard-layout -n -p '/Default/XkbDisable' -t 'bool' -s 'false'
</source>
</syntaxhighlight>


This enables [https://www.x.org/wiki/XKB/ XKB], allowing us to manage our keyboard layout.
This enables [https://www.x.org/wiki/XKB/ XKB], allowing us to manage our keyboard layout.


<source lang=console>
<syntaxhighlight lang=console>
xfconf-query -c keyboard-layout -n -p '/Default/XkbLayout' -t 'string' -s 'us,apl'
xfconf-query -c keyboard-layout -n -p '/Default/XkbLayout' -t 'string' -s 'us,apl'
</source>
</syntaxhighlight>


Defines the keyboard layout itself. The comma-delimited <code>apl</code> specifies a second layout group. Make sure you replace <code>us</code> with the code for your language; a list of these can be found in <code>/usr/share/X11/xkb/rules/evdev.lst</code>, under the <code>layout</code> category.
Defines the keyboard layout itself. The comma-delimited <code>apl</code> specifies a second layout group. Make sure you replace <code>us</code> with the code for your language; a list of these can be found in <code>/usr/share/X11/xkb/rules/evdev.lst</code>, under the <code>layout</code> category.


<source lang=console>
<syntaxhighlight lang=console>
xfconf-query -c keyboard-layout -n -p '/Default/XkbOptions/Group' -t 'string' -s 'grp:win_switch'
xfconf-query -c keyboard-layout -n -p '/Default/XkbOptions/Group' -t 'string' -s 'grp:win_switch'
</source>
</syntaxhighlight>


This tells Xfce to switch to the APL layout only when the <kbd>Windows</kbd> key is pressed. When the <kbd>Windows</kbd> key is released, the layout will return to its previous setting. This is incredibly useful as the <code>apl</code> layouts in XKB do not support <kbd>Space</kbd>, <kbd>Enter</kbd>, or the arrow keys (among basically all the others). A full list of possible keys for switching between keyboard groups is located in <code>/usr/share/X11/xkb/rules/evdev.lst</code>, under the <code>option</code> category.
This tells Xfce to switch to the APL layout only when the <kbd>Windows</kbd> key is pressed. When the <kbd>Windows</kbd> key is released, the layout will return to its previous setting. This is incredibly useful as the <code>apl</code> layouts in XKB do not support <kbd>Space</kbd>, <kbd>Enter</kbd>, or the arrow keys (among basically all the others). A full list of possible keys for switching between keyboard groups is located in <code>/usr/share/X11/xkb/rules/evdev.lst</code>, under the <code>option</code> category.


<source lang=console>
<syntaxhighlight lang=console>
xfconf-query -c keyboard-layout -n -p '/Default/XkbVariant' -t 'string' -s ',dyalog'
xfconf-query -c keyboard-layout -n -p '/Default/XkbVariant' -t 'string' -s ',dyalog'
</source>
</syntaxhighlight>


Specifies that the variant applies to the second layout, <code>apl</code>, due to the preceding comma. The <code>dyalog</code> variant is unique to [[Dyalog]].
Specifies that the variant applies to the second layout, <code>apl</code>, due to the preceding comma. The <code>dyalog</code> variant is unique to [[Dyalog]].


And you're done! Try holding down the Windows key and pressing <kbd>H</kbd> on your keyboard — you should see a <code>∆</code>.
And you're done! Try holding down the Windows key and pressing <kbd>H</kbd> on your keyboard — you should see a <code>∆</code>.
== xmodmap ==
Modifying the Linux keyboard to support APL keys via [https://linux.die.net/man/1/xmodmap xmodmap(1)] is possible, but not recommended — it has been superseded by the [https://wiki.archlinux.org/title/X_keyboard_extension X keyboard extension] (XKB). Generally <syntaxhighlight lang=console inline>xmodmap</syntaxhighlight> is best for simple tasks,<ref>ArchWiki Contributors. [https://wiki.archlinux.org/title/xmodmap xmodmap]. 19 July 2021</ref> which APL keyboards often tend not to be. [[Dyalog APL]], for example, has native support for XKB.<ref name="Dyalog APL XKB"/>
For users who understand the pitfalls, an example <syntaxhighlight lang=console inline>~/.Xmodmap</syntaxhighlight> can be [https://gist.github.com/Russtopia/20ae5ab571d5bed73359ca956d9010a7 found at this GitHub Gist].


== Troubleshooting ==
== Troubleshooting ==
=== Gnome catches keystrokes before Dyalog ===
After upgrading Ubuntu 21.04 (Hirsute Hippo), Gnome catches the keystrokes from the <kbd>Super</kbd> key to show the list of applications, before Dyalog can receive it. [[#setxkbmap|Changing the shifting key]] from <syntaxhighlight lang=console inline>grp:win_switch</syntaxhighlight> to <syntaxhighlight lang=console inline>grp:caps_switch</syntaxhighlight> avoids the issue. Changing it to <syntaxhighlight lang=console inline>grp:rctrl_switch</syntaxhighlight> does not work.


=== Dyalog Overrides Current Keyboard Settings ===
=== Dyalog Overrides Current Keyboard Settings ===


By default, Dyalog APL overrides the current [https://www.x.org/wiki/XKB/ XKB] configuration to use the Meta ("Windows") key as the modifier for entering APL symbols. If the user manages their keyboard configuration manually using the techniques described on this page, this behavior can be quite troublesome.
Prior to version 18.2, Dyalog APL would override the current [https://www.x.org/wiki/XKB/ XKB] configuration to use the Meta ("Windows") key as the modifier for entering APL symbols. If the user manages their keyboard configuration manually using the techniques described on this page, this behavior can be quite troublesome.


To run Dyalog in the terminal without overriding ("hijacking") the user keyboard configuration, run <code>dyalog</code> with the <code>-nokbd</code> option:
To run Dyalog in the terminal without overriding ("hijacking") the user keyboard configuration, run <code>dyalog</code> with the <code>-nokbd</code> option:


<source lang=bash>
<syntaxhighlight lang=bash>
dyalog -nokbd
dyalog -nokbd
</source>
</syntaxhighlight>


The following script can be used to launch RIDE, immediately connecting a new Dyalog instance, without changing the xkb settings:
The following script can be used to launch RIDE, immediately connecting a new Dyalog instance, without changing the xkb settings:


<source lang=bash>
<syntaxhighlight lang=bash>
#!/usr/bin/env sh
#!/usr/bin/env sh
env RIDE_CONNECT=localhost:4502 ride &
env RIDE_CONNECT=localhost:4502 ride &
dyalog +s -q -nokbd RIDE_INIT=SERVE:*:4502
dyalog +s -q -nokbd RIDE_INIT=SERVE:*:4502
</source>
</syntaxhighlight>


The keyboard layout changing is done by the file at <code>/opt/mdyalog/*/64/unicode/aplkeys.sh</code>, so changing it changes the behavior (clearing it entirely stops the automatic keyboard layout switching). Note that the file exists for each installed version and is reset on any update, so it may need to be modified multiple times.
The keyboard layout changing is done by the file at <code>/opt/mdyalog/*/64/unicode/aplkeys.sh</code>, so changing it changes the behavior (clearing it entirely stops the automatic keyboard layout switching). Note that the file exists for each installed version and is reset on any update, so it may need to be modified multiple times.
Line 183: Line 214:
=== APL Keyboard Remains After Dyalog is Closed ===
=== APL Keyboard Remains After Dyalog is Closed ===


Dyalog overrides the current keyboard configuration, as described in [[#Dyalog_Overrides_Current_Keyboard_Settings|this section]], but fails to return the user to their previous keyboard configuration on exit. To solve this, create a custom [[wikipedia:Bash_(Unix_shell)|Bash]] script to save and revert keyboard settings upon exiting Dyalog APL:<ref>Adám Brudzewsky. [https://stackoverflow.com/questions/63431922/dyalog-apl-hijack-windows-key-and-do-not-give-it-back-fedora-32-gnome-free-lic/63433845#63433845 Stack Overflow answer]. 17 Aug, 2020</ref>
Previous versions of Dyalog override the current keyboard configuration, as described in [[#Dyalog_Overrides_Current_Keyboard_Settings|this section]], but even using the default keyboard configuration by starting Dyalog 18.2 or later with
 
<syntaxhighlight lang=bash>
dyalog --keyboard
</syntaxhighlight>
 
fails to return the user to their previous keyboard configuration on exit. To solve this, create a custom [[wikipedia:Bash_(Unix_shell)|Bash]] script to save and revert keyboard settings upon exiting Dyalog APL:<ref>Adám Brudzewsky. [https://stackoverflow.com/questions/63431922/dyalog-apl-hijack-windows-key-and-do-not-give-it-back-fedora-32-gnome-free-lic/63433845#63433845 Stack Overflow answer]. 17 Aug, 2020</ref>


<source lang=bash>
<syntaxhighlight lang=bash>
#!/usr/bin/sh
#!/usr/bin/sh
OLDLAYOUT=$(setxkbmap -query | sed -n 's/^layout://p')
OLDLAYOUT=$(setxkbmap -query | sed -n 's/^layout://p')
Line 194: Line 231:
OLDVARIANT=$(echo $OLDVARIANT | sed 's/^$/,/')
OLDVARIANT=$(echo $OLDVARIANT | sed 's/^$/,/')
setxkbmap -layout $OLDLAYOUT -variant $OLDVARIANT -option -option $OLDOPTION
setxkbmap -layout $OLDLAYOUT -variant $OLDVARIANT -option -option $OLDOPTION
</source>
</syntaxhighlight>


=== Settings reverted during X Windows session ===
=== Settings reverted during X Windows session ===


Since at least March 2020 there have been issues with <source lang=console inline>setxkbmap</source> settings being reset without user instruction under the [[wikipedia:X Windows System|X Windows System]].
Since at least March 2020 there have been issues with <syntaxhighlight lang=console inline>setxkbmap</syntaxhighlight> settings being reset without user instruction under the [[wikipedia:X Windows System|X Windows System]].


Below is a script written in [[wikipedia:Raku (programming language)|Raku]] that continuously checks for this undesirable reset behavior and puts the intended settings back in place.<ref>John Longwalker. [https://5ab5traction5.bearblog.dev/ 5ab5traction5 blog]. [https://5ab5traction5.bearblog.dev/apl-keyboard-keeper/ Raku to the Rescue: APL Keyboard Keeper]. 29 Jun, 2020</ref>
Below is a script written in [[wikipedia:Raku (programming language)|Raku]] that continuously checks for this undesirable reset behavior and puts the intended settings back in place.<ref>John Longwalker. [https://5ab5traction5.bearblog.dev/ 5ab5traction5 blog]. [https://5ab5traction5.bearblog.dev/apl-keyboard-keeper/ Raku to the Rescue: APL Keyboard Keeper]. 29 Jun, 2020</ref>


<source lang=perl6>
<syntaxhighlight lang=perl6>
#!/usr/bin/env raku
#!/usr/bin/env raku


Line 267: Line 304:
   }
   }
}
}
</source>
</syntaxhighlight>


== References ==
== References ==

Revision as of 10:32, 11 September 2022

This article is specific for Linux. For Hardware and other platforms, see Typing glyphs.

Since mid-2012, most Linux distributions with X11 and Wayland have Dyalog APL keyboard support included with the distribution,[1] using xkb, the X Keyboard Extension.[2]

setxkbmap

The simplest way to set up an APL keyboard on Linux is with the following setxkbmap command. Enter the following in your terminal emulator of choice:

setxkbmap -layout us,apl -variant ,dyalog -option grp:switch

An explanation:

  • -layout us,apl assigns us (U.S. English) to be the primary layout, whereas apl is secondary
  • -option grp:switch assigns Right Alt to switch to the secondary apl layout when it is pressed, otherwise us is used
  • -variant ,dyalog assigns the Dyalog APL variant to the apl layout which contains modifiations unique to the Dyalog language (Note the preceding comma)

A full list of keys that can be used to switch layouts is included in /usr/share/X11/xkb/rules/evdev.lst under the option category.

Note:

  • These changes are not permanent; the user will have to select one of a myriad of methods to run the command on startup. Alternatively, if they use one of the desktop environments listed below, they can follow those instructions.
  • If you want to specify a different language, say for United Kingdom, specify gb instead of us (not uk)
  • If you want to specify a different layout, dvorak, bepo, etc, change the variant flag to dvorak,dyalog.

libinput

X11 and Wayland use XKB rules to determine their layout. To set a layout create a file called 00-keyboard.conf at /etc/X11/xorg.conf.d or /usr/etc/X11/corg.conf.d, ensuring you have permissions, and edit it to:

Section "InputClass"
        Identifier "system-keyboard"
        MatchIsKeyboard "on"
        Option "XkbLayout" "us,apl"
        Option "XkbVariant" ",dyalog"
        Option "XkbOptions" "grp:switch"
EndSection

The options "us,apl", ",dyalog", and "grp:switch" are the same as in setxkbmap and can be changed to better suit your environment.

Once saved this will affect any future session. To change the current session and test out layouts, use setxkbmap.

GNOME

GUI

  1. Open the Activities menu; this is located in the top-left corner of a default GNOME 3 session (alternatively, use your Super key to open the Activities overlay):
    GNOME Keyboard Step 1: Open Activities Menu
  2. Search for "startup." When the Startup Applications program is highlighted, press the Enter key to open it:
    GNOME Keyboard Step 2: Search for Startup Applications
  3. Select the Add button on the right-hand side:
    GNOME Keyboard Step 3: Click the Add button in Startup Applications window
  4. Provide a name, enter your setxkbmap command, and click Add when finished:
    GNOME Keyboard Step 4: Enter the relevant information for your command

Terminal

  1. Navigate to ~/.config/autostart and create a .desktop with any name that will help you remember its function.
  2. Add the following to the contents of your file, customizing to suit your needs:
    [Desktop Entry]
    Type=Application
    Exec=setxkbmap -layout us,apl -variant ,dyalog -option grp:switch
    Hidden=false
    NoDisplay=false
    X-GNOME-Autostart-enabled=true
    Name[en_US]=apl-keyboard
    Name=apl-keyboard
    Comment[en_US]=
    Comment=

LXDE

  1. Prepend an @ to the setxkbmap command from above:
    @setxkbmap -layout us,apl -variant ,dyalog -option grp:switch
  2. Add it as a line in your user's LXDE autostart file, located at:
    ~/.config/lxsession/LXDE/autostart

For Lubuntu versions up to and including 18.04 (before the LXQt split), the location of autostart is ~/.config/lxsession/Lubuntu/autostart.

LXQt

GUI

  1. From your LXQt panel, navigate to PreferencesLXQt SettingsSession Settings; alternatively, enter lxqt-config-session in your terminal emulator. You will be greeted with the following window:
    LXQt Autostart menu of Session Settings window
  2. Select the LXQt Autostart dropdown (it will be highlighted as shown above) and click the Add button to display the following pop-up window:
    LXQt add a new autostart menu item
  3. Provide a name, enter your setxkbmap command, and click OK when finished.

Terminal

The above GUI approach merely creates a .desktop file in the user's ~/.config/autostart. Create your own file in the autostart directory whose contents are as follows, to replicate the functionality achieved through the GUI:

[Desktop Entry]
Exec=setxkbmap -layout us,apl -variant ,dyalog -option grp:switch
Name=apl-keyboard
OnlyShowIn=LXQt;
Type=Application
Version=1.0

MATE

GUI

  1. Open your MATE menu (in the top-left corner of a default environment) and select Control Center at the bottom of the window:
    Launch the Control Center from the MATE menu
  2. Scroll down through the main window, and under the Personal category, select Startup Applications:
    Scroll down to the Startup Applications option
  3. Click the Add button on the right-hand side:
    Click Add to add a new startup command
  4. Provide a name, enter your setxkbmap command, and click Add when finished:
    Enter the setxkbmap command you wish to use

Terminal

Navigate to ~/.config/autostart and create a .desktop with any name that will help you remember its function.

Add the following to the contents of your file, customizing to suit your needs:

[Desktop Entry]
Type=Application
Exec=setxkbmap -layout us,apl -variant ,dyalog -option grp:switch
Hidden=false
X-MATE-Autostart-enabled=true
Name[en_US]=apl-keyboard
Name=apl-keyboard
Comment[en_US]=
Comment=
X-MATE-Autostart-Delay=0

Wayland

Currently, Wayland uses XKB for keyboards, but they are not modifiable during runtime using e.g. setxkbmap by default. The keyboard layout must be configured and then the session restarted.

GNOME Tweaks

The Tweaks tool allows configuration beyond the defaults enabled in GNOME.

  1. Install GNOME Tweaks using apt or dnf, or by searching your distribution's Software Center.
  2. Start GNOME Tweaks by either:
    1. Using a terminal, type gnome-tweaks and press Enter.
    2. Using the GUI:
      1. Open the Activities menu; this is located in the top-left corner of a default GNOME 3 session (alternatively, use your Super key to open the Activities overlay):
        Wayland Keyboard set up with GNOME Tweaks Step 2.1: Open Activities Menu
      2. Search for "Tweaks"
        Wayland Keyboard set up with GNOME Tweaks Step 2.2: Start GNOME Tweaks
  3. Open Keyboard & Mouse Panel and enable "Show Extended Input Sources"
    Wayland Keyboard set up with GNOME Tweaks Step 3: Open Keyboard & Mouse Panel
  4. Open the Additional Layout Options and tick one or more of the options under "Switching to another layout"
    Wayland Keyboard set up with GNOME Tweaks Step 4: Open Additional Layout Options
  5. Go to Settings → Region & Language → Add a new input source. Both English (United Kingdom) and English (United States) will have several APL layout options to choose from.
  6. Restart the session (for example, by logging out and logging in again).

Xfce

Xfce's GUI (Settings ManagerKeyboardLayout) is unable to set up an APL-compatible keyboard. Therefore, we must do it ourselves.

Xfce ships with a utility, xfconf-query, which allows you to manage Xfce's XML configuration files on the command line. Enter the following commands into your terminal:

xfconf-query -c keyboard-layout -n -p '/Default/XkbDisable' -t 'bool' -s 'false'

This enables XKB, allowing us to manage our keyboard layout.

xfconf-query -c keyboard-layout -n -p '/Default/XkbLayout' -t 'string' -s 'us,apl'

Defines the keyboard layout itself. The comma-delimited apl specifies a second layout group. Make sure you replace us with the code for your language; a list of these can be found in /usr/share/X11/xkb/rules/evdev.lst, under the layout category.

xfconf-query -c keyboard-layout -n -p '/Default/XkbOptions/Group' -t 'string' -s 'grp:win_switch'

This tells Xfce to switch to the APL layout only when the Windows key is pressed. When the Windows key is released, the layout will return to its previous setting. This is incredibly useful as the apl layouts in XKB do not support Space, Enter, or the arrow keys (among basically all the others). A full list of possible keys for switching between keyboard groups is located in /usr/share/X11/xkb/rules/evdev.lst, under the option category.

xfconf-query -c keyboard-layout -n -p '/Default/XkbVariant' -t 'string' -s ',dyalog'

Specifies that the variant applies to the second layout, apl, due to the preceding comma. The dyalog variant is unique to Dyalog.

And you're done! Try holding down the Windows key and pressing H on your keyboard — you should see a .

xmodmap

Modifying the Linux keyboard to support APL keys via xmodmap(1) is possible, but not recommended — it has been superseded by the X keyboard extension (XKB). Generally xmodmap is best for simple tasks,[3] which APL keyboards often tend not to be. Dyalog APL, for example, has native support for XKB.[2]

For users who understand the pitfalls, an example ~/.Xmodmap can be found at this GitHub Gist.

Troubleshooting

Gnome catches keystrokes before Dyalog

After upgrading Ubuntu 21.04 (Hirsute Hippo), Gnome catches the keystrokes from the Super key to show the list of applications, before Dyalog can receive it. Changing the shifting key from grp:win_switch to grp:caps_switch avoids the issue. Changing it to grp:rctrl_switch does not work.

Dyalog Overrides Current Keyboard Settings

Prior to version 18.2, Dyalog APL would override the current XKB configuration to use the Meta ("Windows") key as the modifier for entering APL symbols. If the user manages their keyboard configuration manually using the techniques described on this page, this behavior can be quite troublesome.

To run Dyalog in the terminal without overriding ("hijacking") the user keyboard configuration, run dyalog with the -nokbd option:

dyalog -nokbd

The following script can be used to launch RIDE, immediately connecting a new Dyalog instance, without changing the xkb settings:

#!/usr/bin/env sh
env RIDE_CONNECT=localhost:4502 ride &
dyalog +s -q -nokbd RIDE_INIT=SERVE:*:4502

The keyboard layout changing is done by the file at /opt/mdyalog/*/64/unicode/aplkeys.sh, so changing it changes the behavior (clearing it entirely stops the automatic keyboard layout switching). Note that the file exists for each installed version and is reset on any update, so it may need to be modified multiple times.

APL Keyboard Remains After Dyalog is Closed

Previous versions of Dyalog override the current keyboard configuration, as described in this section, but even using the default keyboard configuration by starting Dyalog 18.2 or later with

dyalog --keyboard

fails to return the user to their previous keyboard configuration on exit. To solve this, create a custom Bash script to save and revert keyboard settings upon exiting Dyalog APL:[4]

#!/usr/bin/sh
OLDLAYOUT=$(setxkbmap -query | sed -n 's/^layout://p')
OLDVARIANT=$(setxkbmap -query | sed -n 's/^variant://p')
OLDOPTION=$(setxkbmap -query | sed -n 's/^options://p')
dyalog
OLDLAYOUT=$(echo $OLDLAYOUT | sed 's/^$/,/')
OLDVARIANT=$(echo $OLDVARIANT | sed 's/^$/,/')
setxkbmap -layout $OLDLAYOUT -variant $OLDVARIANT -option -option $OLDOPTION

Settings reverted during X Windows session

Since at least March 2020 there have been issues with setxkbmap settings being reset without user instruction under the X Windows System.

Below is a script written in Raku that continuously checks for this undesirable reset behavior and puts the intended settings back in place.[5]

#!/usr/bin/env raku

# Small script to ensure that APL keyboard layout is still set in xkb settings.
# Note that this is a patch for some sort of deranged time-based reset of these
# settings that is happening at a lower level of the Xorg-based Linux user experience.
#
# It's not clear what is causing these resets but this script allows us to more
# or less not care about it and get on with our hacking.
#
# Released under Artistic License by John Longwalker 2020

my $total-checks = 0;
sub xkbmap-contains-apl() {
  $total-checks++;
  so qx{ setxkbmap -query | grep '^layout:.*\<apl\>' }; # shell-out is easy as usual in a Perl
}

my $total-resets = 0;
sub set-xkbmap-for-apl($key, $verbose) {
  say "Reset total is now {++$total-resets} -- {DateTime.now}"
  	if $verbose;
  my $xkb-settings = chomp qx{ setxkbmap -query };

  my ($layout, $variant, $options);
  if $xkb-settings ~~ /^^ "layout:" \s* $<layout>=(<.graph>*) $$/ {
  	$layout = $<layout>.Str;
  } else {
  	die "Aborting. The xkb settings do not specify any layout:\n$xkb-settings";
  }

  if $xkb-settings ~~ /^^ "variant:" \s* $<variant>=(<.graph>*) $$/ {
  	$variant = $<variant>.Str;
  }

  if $xkb-settings ~~ /^^ "options:" \s* $<options>=(<.graph>*) $$/ {
  	$options = $<options>.Str;
  }

  $layout  = ($layout, 'apl').join(',');
  $variant = $variant ?? ($variant, 'dyalog')
                      !! 'dyalog';
  $options = $options ?? ($options, "grp:$key").join(',') 
                      !! "grp:$key";
  my $invocation = "setxkbmap -layout $layout -variant $variant -option $options";
  say "Invocation: $invocation"
    if $verbose;
  qqx{ $invocation };
}

# You can use --interval, --key, and -v/--verbose on the command line.
sub MAIN(:$interval = 30, :$key = 'switch', :v($verbose) = False) {
  react {
    whenever Supply.interval($interval) {
      set-xkbmap-for-apl($key, $verbose)
        if not xkbmap-contains-apl;
    }

    whenever signal(SIGINT) {
      say "Reset a total of $total-resets out of $total-checks checks"
      	if $verbose;
      exit;
    }
  }
}

References

  1. Dyalog Forums. Keyboard setup on Linux. Sep 21, 2010.
  2. 2.0 2.1 Geoff Streeter. Supporting APL keyboards on Linux. Dyalog '10.
  3. ArchWiki Contributors. xmodmap. 19 July 2021
  4. Adám Brudzewsky. Stack Overflow answer. 17 Aug, 2020
  5. John Longwalker. 5ab5traction5 blog. Raku to the Rescue: APL Keyboard Keeper. 29 Jun, 2020
APL development [edit]
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