macOS 10.12+ keyboard remap script, check https://developer.apple.com/library/content/technotes/tn2450/_index.html to add you own remap options.

keyboard_remap.sh

#!/usr/bin/env bash

echo "This script setup switch left alt/cmd and set caps-lock to f18 on user login"

cat << 'EOF' | sudo tee /usr/local/bin/me.qnub.pc-to-mac-kb.sh
#!/usr/bin/env bash
hidutil property --set '{"UserKeyMapping":
    [{"HIDKeyboardModifierMappingSrc":0x7000000e2,
      "HIDKeyboardModifierMappingDst":0x7000000e3},
     {"HIDKeyboardModifierMappingSrc":0x7000000e3,
      "HIDKeyboardModifierMappingDst":0x7000000e2},
     {"HIDKeyboardModifierMappingSrc":0x700000039,
      "HIDKeyboardModifierMappingDst":0x70000006d},
     {"HIDKeyboardModifierMappingSrc":0x700000082,
      "HIDKeyboardModifierMappingDst":0x70000006d}]
}'

sleep 12
exit 0
EOF

sudo chmod a+x /usr/local/bin/me.qnub.pc-to-mac-kb.sh

cat << 'EOF' | sudo tee /Library/LaunchAgents/me.qnub.pc-to-mac-kb.plist
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>Label</key>
    <string>me.qnub.pc-to-mac-kb</string>
    <key>ProgramArguments</key>
    <array>
        <string>/usr/local/bin/me.qnub.pc-to-mac-kb.sh</string>
    </array>
    <key>RunAtLoad</key>
    <true/>
    <key>KeepAlive</key>
    <false/>
</dict>
</plist>
EOF