execute command on X11 startup

using X11 startup file – it work with any window manager

Create a .desktop file in ~/.config/autostart directory

Execute a single command with a parameter when X11 start

cat > ~/.config/autostart/start_script.desktop <<EOF
[Desktop Entry]
Name=start_script
Type=Application
Exec=setxkbmap pt
EOF

Execute multiple commands when X11 start

cat > ~/.config/autostart/start_script.desktop <<EOF
[Desktop Entry]
Name=start_script
Type=Application
Exec=sh -c "setxkbmap pt; xterm &"
EOF

using Openbox startup file – work only with openbox

All lines in ~/.config/openbox/autostart file will be executed on openbox startup

echo 'tilda' >> ~/.config/openbox/autostart