objective-c - Swift:如何通过 SCDynamicStoreCopyConsoleUser 获取控制台用户、UID 和 GID？

Question

我可以使用 python 从 SCDynamicStoreCopyConsoleUser 获取用户名、UID 和 GID:

 #!/usr/bin/python
 from SystemConfiguration import SCDynamicStoreCopyConsoleUser
 cfuser = SCDynamicStoreCopyConsoleUser( None, None, None )
 print cfuser[0] # Returns console user, e.g.: myUsername
 print cfuser[1] # Returns console user’s UID, e.g.: 501
 print cfuser[2] # Returns console user’s GID, e.g.: 20

如何使用 Swift 获得相同的返回？

SCDynamicStoreCopyConsoleUser 的 Swift 声明

 func SCDynamicStoreCopyConsoleUser(_ store: SCDynamicStore!,
                                    _ uid: CMutablePointer<uid_t>,
                                    _ gid: CMutablePointer<gid_t>) -> Unmanaged<CFString>!

我的快速通话

 var uid: CMutablePointer<uid_t>!
 var gid: CMutablePointer<gid_t>!

 var cfuser: NSArray = [SCDynamicStoreCopyConsoleUser(nil,uid,gid)]

 // the return has only one element containing the username

Answer 1

Swift 函数 SCDynamicStoreCopyConsoleUser需要 CMutablePointer<uid_t>参数意味着您必须传递 uid_t 的地址多变的。另外你应该检查调用是否成功(否则返回nil)，你呢必须按照中所述转换返回的非托管对象 Working with Cocoa Data Types :

import SystemConfiguration

var uid: uid_t = 0
var gid: gid_t = 0

if let theResult = SCDynamicStoreCopyConsoleUser(nil, &uid, &gid) {
    let name = theResult.takeUnretainedValue()
    println("name = \(name), uid = \(uid), gid = \(gid)")
} else {
    println("failed")
}