命令swift后获取终端输出

我使用以下代码在终端中运行一些命令：

system("the command here")

在我想知道运行此命令的结果后,例如如果我跑

system("git status")

我想阅读有关我的回购变更的实际信息.有没有办法在swift中做到这一点？

NSTask是将另一个程序作为子进程运行的类.您可以
捕获程序的输出,错误输出,退出状态等等.

扩展我对xcode 6 swift system() command的回答,
这是一个简单的实用程序函数,用于同步运行命令,
并返回输出,错误输出和退出代码(现在更新为Swift 2)：

func runCommand(cmd : String,args : String...) -> (output: [String],error: [String],exitCode: Int32) {

    var output : [String] = []
    var error : [String] = []

    let task = NSTask()
    task.launchPath = cmd
    task.arguments = args

    let outpipe = NSPipe()
    task.standardOutput = outpipe
    let errpipe = NSPipe()
    task.standardError = errpipe

    task.launch()

    let outdata = outpipe.fileHandleForReading.readDataToEndOfFile()
    if var string = String.fromCString(UnsafePointer(outdata.bytes)) {
        string = string.stringByTrimmingCharactersInSet(NSCharacterSet.newlineCharacterSet())
        output = string.componentsSeparatedByString("\n")
    }

    let errdata = errpipe.fileHandleForReading.readDataToEndOfFile()
    if var string = String.fromCString(UnsafePointer(errdata.bytes)) {
        string = string.stringByTrimmingCharactersInSet(NSCharacterSet.newlineCharacterSet())
        error = string.componentsSeparatedByString("\n")
    }

    task.waitUntilExit()
    let status = task.terminationStatus

    return (output,error,status)
}

样品用法：

let (output,status) = runCommand("/usr/bin/git",args: "status")
print("program exited with status \(status)")
if output.count > 0 {
    print("program output:")
    print(output)
}
if error.count > 0 {
    print("error output:")
    print(error)
}

或者,如果您只对输出感兴趣,而不是对输出感兴趣
错误消息或退出代码：

let output = runCommand("/usr/bin/git",args: "status").output

输出和错误输出作为字符串数组返回,一个
每行的字符串.

runCommand()的第一个参数必须是a的完整路径
可执行文件,例如“/usr/bin/git”.你可以使用shell启动程序(这也是system()也是如此)：

let (output,status) = runCommand("/bin/sh",args: "-c","git status")

优点是自动找到“git”可执行文件
通过默认搜索路径.缺点是你必须这样做
如果它们包含空格或其他,则正确引用/转义参数
在shell中具有特殊含义的字符.

Swift 3的更新：

func runCommand(cmd : String,exitCode: Int32) {

    var output : [String] = []
    var error : [String] = []

    let task = Process()
    task.launchPath = cmd
    task.arguments = args

    let outpipe = Pipe()
    task.standardOutput = outpipe
    let errpipe = Pipe()
    task.standardError = errpipe

    task.launch()

    let outdata = outpipe.fileHandleForReading.readDataToEndOfFile()
    if var string = String(data: outdata,encoding: .utf8) {
        string = string.trimmingCharacters(in: .newlines)
        output = string.components(separatedBy: "\n")
    }

    let errdata = errpipe.fileHandleForReading.readDataToEndOfFile()
    if var string = String(data: errdata,encoding: .utf8) {
        string = string.trimmingCharacters(in: .newlines)
        error = string.components(separatedBy: "\n")
    }

    task.waitUntilExit()
    let status = task.terminationStatus

    return (output,status)
}