xmodmap-to-xkb-layout.sh

#!/usr/bin/env bash

#
# This scripts converts a custom xmodmap configuration file
# into a system-wide XKB layout and applies it.
#

set -euo pipefail

# Reset layout and remap options to the default ones.
# i.e. no remaps, latam layout.
layout::apply_defaults() {
    setxkbmap -option && setxkbmap latam
}
layout::apply_defaults

# Dump this default layout as an xmodmap file
xmodmap -pke > xmodmap/xmodmap_latam_defaults.lst

# Dump this default layout as an XKB file
xkbcomp -xkb $DISPLAY xkb/latam_defaults.xkb

# Apply any remappings you use, i.e. Caps Lock <-> Escape, for me
setxkbmap -option caps:swapescape

# Apply the customized layout using the custom, readable, xmodmap config file,
# This may take a minute or so.
xmodmap xmodmap/xmodmap_latam_customs.lst

# Dump the just-applied customized layout as an XKB file
xkbcomp -xkb $DISPLAY xkb/latam_custom.xkb

# Get the symbols portion of the applied layout and dump it into a new xkb file.
xkb_symbols_portion=$(
    sed -n '/^xkb_symbols/, /^xkb_/p' xkb/latam_custom.xkb | head -n-1
)
echo "${xkb_symbols_portion}" | sudo tee xkb/latam_custom_symbols.xkb

# Extract remap includes, defined between quotes in xkb_symbols's header
remaps_includes=$(echo "$xkb_symbols_portion" | head -n1 | cut -d'"' -f2)

# Get the name the custom layout is based on
setxkbmap latam # Reset layout to the default one
default_layout_name=$(setxkbmap -query | grep layout | cut -d":" -f2 | xargs)

temp_file=.temp_custom_xkb_layout.xkb

# Build the xkb-like header with the custom information
echo "xkb_symbols \"${default_layout_name}_custom\" {" > ${temp_file}
echo -e "\tinclude \"${remaps_includes}\"" >> ${temp_file}

# Copy generated symbols (except the header).
tail -n +2 xkb/latam_custom_symbols.xkb >> ${temp_file}

# Link the generated XKB file
/usr/bin/env mv -f ${temp_file} xkb/latam_custom_symbols.xkb
sudo ln -srf xkb/latam_custom_symbols.xkb /usr/share/X11/xkb/symbols/latam_custom

# Reset layout and remap options to the default ones, again
layout::apply_defaults

# Create variant from new custom layout
variant_name=vimlikekeys
variant_section="
// Latin American Spanish Vim-Like mapping (by Lu0), customized to
// keep navigation, media and number keys near the home row
partial alphanumeric_keys
xkb_symbols \"${variant_name}\" {
	include \"${default_layout_name}_custom\"

    name[group1]=\"Spanish (Latin American, Vim-like keys)\";
};
"
sudo cp /usr/share/X11/xkb/symbols/latam /usr/share/X11/xkb/symbols/latam_orig # backup
echo -n "${variant_section}" | sudo tee -a /usr/share/X11/xkb/symbols/latam

# Apply the new, custom, XKB configuration
setxkbmap latam vimlikekeys

# Wait for user confirmation to persist the layout
seconds=15
sleep ${seconds}

echo -e "\nHit ENTER to keep this configuration,"
echo "or WAIT to restore the default one."

if read -t ${seconds}; then
    echo -e '\nXKBLAYOUT="latam"\nXKBVARIANT="vimlikekeys"' \
        | sudo tee -a /etc/default/keyboard
else
    echo -e "\nRestoring previous configuration..."
    layout::apply_defaults
    echo -e "You can reapply the layout with:"
    echo -e "\tsetxkbmap ${default_layout_name} ${variant_name}"
fi