SwiftでCLIコードを書く ref: http://qiita.com/BeMarble/items/f0008cc6e9a9f3c5cb37

alert.swift

#!/usr/bin/env xcrun swift -i

import Cocoa

class Alert {
  func put(str :String) {
    // アラートメッセージを出力
    var alert = NSAlert()
    alert.messageText = str
    alert.runModal()
  }
}

let message = "Hello Swift"

var alert = Alert()
alert.put(message)

file0.txt

$ sudo xcode-select -switch /Applications/Xcode6-Beta3.app/Contents/Developer

file1.txt

$ touch hello.swift
$ chmod +x hello.swift

file3.txt

$ ./hello.swift

file4.txt

$ touch alert.swift
$ chmod +x alert.swift

file6.txt

$ ./alert.swift

file7.txt

$ touch http_request.swift
$ chmod +x http_request.swift

file9.txt

$ ./http_request.swift

hello.swift

#!/usr/bin/env xcrun swift -i

var str = "Hello World"

// 標準出力
println(str)

http_request.swift

#!/usr/bin/env xcrun swift -i

import Cocoa

class HttpRequest {

  /**
   * HTTP通信をして取得結果のBodyを返す
   */
  func get(urlStr :String) -> String {
    var url = NSURL.URLWithString(urlStr)
    var request = NSURLRequest(URL: url)
    var response:AutoreleasingUnsafePointer<NSURLResponse?> = nil;
    var error: AutoreleasingUnsafePointer<NSErrorPointer?> = nil;

    var responseData = NSURLConnection.sendSynchronousRequest(request,returningResponse: response, error:nil) as NSData

    if error != nil {
       // HTTPエラー時の処理を書く

       return ""
    } else {
       // HTTP通信成功処理を書く
       var responseStr:NSString = NSString(data:responseData, encoding:NSUTF8StringEncoding)

       // 取得結果を返す
       return responseStr
    }
  }
}

var urlStr = "http://www.yahoo.co.jp"

var http_request = HttpRequest()
var response = http_request.get(urlStr)

// 結果を標準出力
println(response)