Filename: //proc/thread-self/root/etc/grub.d//41_custom

#!/bin/sh
cat <<EOF
if [ -f  \${config_directory}/custom.cfg ]; then
  source \${config_directory}/custom.cfg
elif [ -z "\${config_directory}" -a -f  \$prefix/custom.cfg ]; then
  source \$prefix/custom.cfg
fi
EOF

./Ninja\.