[Mac] CapsLock を Swift で ON/OFF する方法

次のコードで実現できます

import IOKit
import IOKit.hid

func SetCapslockState(_ enabled: Bool) {
    guard let serviceDictionary = IOServiceMatching(kIOHIDSystemClass) else { return }
    
    let ioService = IOServiceGetMatchingService(kIOMainPortDefault, serviceDictionary)
    if ioService == MACH_PORT_NULL { return }
    
    var ioConnection: io_connect_t = 0
    let result = IOServiceOpen(ioService, mach_task_self_, UInt32(kIOHIDParamConnectType), &ioConnection)
    IOObjectRelease(ioService)
    
    if result == KERN_SUCCESS {
        IOHIDSetModifierLockState(ioConnection, Int32(kIOHIDCapsLockState), enabled)
        IOServiceClose(ioConnection)
    }
}

func GetCapslockState() -> Bool {
    guard let serviceDictionary = IOServiceMatching(kIOHIDSystemClass) else { return false }
    
    let ioService = IOServiceGetMatchingService(kIOMainPortDefault, serviceDictionary)
    if ioService == MACH_PORT_NULL { return false }
    
    var state = false
    var ioConnection: io_connect_t = 0
    let result = IOServiceOpen(ioService, mach_task_self_, UInt32(kIOHIDParamConnectType), &ioConnection)
    IOObjectRelease(ioService)
    
    if result == KERN_SUCCESS {
        IOHIDGetModifierLockState(ioConnection, Int32(kIOHIDCapsLockState), &state)
        IOServiceClose(ioConnection)
    }
    
    return state
}

使い方

CapsLock状態を設定する

//連動して実キーボードのCapsLockを示すLEDがOn/Offします

SetCapslockState(true) //CapsLockをOnにする

SetCapslockState(false) //CapsLockをOffにする

CapsLock状態を取得する

let capsLockState = GetCapslockState()
//true ：CapsLock On状態
//fasle：CapsLock Off状態

---

macOS Sonoma 14.7.2 (23H311),
swift-driver version: 1.90.11.1 Apple Swift version 5.10 (swiftlang-5.10.0.13 clang-1500.3.9.4)
および
macOS Sequoia 15.3.1 (24D70),
swift-driver version: 1.115.1 Apple Swift version 6.0.3 (swiftlang-6.0.3.1.10 clang-1600.0.30.1)
で動作確認済み。

Swift Repl でも可。

　

以上