A swift script to make dealing with new swift scripts a little easier :)

swift-script

#!/usr/bin/env swift

#if os(OSX)
    import Darwin
#else
    import Glibc
#endif

import Foundation

// MARK: Failure

@noreturn func fail(_ msg: String) {
    print("Error: \(msg)")
    exit(1)
}

func run(_ command: String, allowFailure: Bool = false) {
    let result = system(command)
    if allowFailure { return }
    else if result != 0 {
      fail("error code \(result)")
    }
}

func passes(_ command: String) -> Bool {
  return system(command) == 0
}

func getInput() -> String {
  return readLine(strippingNewline: true) ?? ""
}

func commandExists(_ command: String) -> Bool {
  return system("hash \(command) 2>/dev/null") == 0
}

// MARK: Command

protocol Command {
  static var description: String { get }
  static func execute(with args: [String], in directory: String)
}

extension Command {
  static var description: String {
    return ""
  }
}

// MARK: Tree

var commandTree: [String : Command.Type] = [:]

// MARK: Help

struct Help: Command {
    static func execute(with args: [String], in directory: String) {
      var help = "Available Commands:\n\n"
      help += commandTree
          .map { key, val in "\t\(key): \(val.description)"}
          .joined(separator: "\n")
      help += "\n"
      print(help)
    }
}

commandTree["help"] = Help.self

// MARK: Custom Commands

struct New: Command {
    static func execute(with args: [String], in directory: String) {
      guard commandExists("wget") else {
        fail("wget required to create new script. Recommended to install through Homebrew: http://brew.sh/")
      }
      guard args.count == 1, let name = args.first else {
        fail("Unexpected arguments: \(args). Expected single argument as name of script")
      }

      let templateUrl = "https://gist.githubusercontent.com/LoganWright/899acec46512a966653206f5dcc27d2a/raw/042f592b24a27f317d7c773fb750525e0a56bb98/swift-script-template.swift"
      run("wget \(templateUrl) -O \(name)")

      print("Successfully created swift script \(name)")
      print("Use the following to run your script")
      print()
      print("xcrun")
      print("\txcrun swift ./\(name)")
      print()
      print("xcrun: toolchain")
      print("\txcrun --toolchain swift swift ./\(name)")
      print()
      print("run directly")
      print("\tRun only once")
      print("\t\tchmod +x ./\(name)")
      print("\tThen call directly after that")
      print("\t\t./\(name)")
      print()
      print("run from bin")
      print("\trun only once")
      print("\t\tchmod +x ./\(name)")
      print("\t\tmv ./\(name) /usr/local/bin/\(name)")
      print("\tnow call directly")
      print("\t\t\(name)")
      print()
    }
}

struct AddToBin: Command {
  static func execute(with args: [String], in directory: String) {
    guard args.count == 1, let file = args.first else {
      fail("Unexpected arguments: \(args). Expected single argument as file of script to move")
    }

    guard passes("test -f \"\(file)\"") else {
      fail("Unable to find file \(file)")
    }

    guard let extractedName = file.components(separatedBy: "/").last else {
      fail("Unable to find file name")
    }

    print("Custom name? (press return to use \(extractedName))")
    var name = ""
    if let input = readLine(strippingNewline: true) where !input.isEmpty {
      name = input
    } else {
      name = extractedName
    }

    run("chmod +x \(file)")
    run("mv \(file) /usr/local/bin/\(name)")
  }
}

// MARK: Tree

commandTree["new"] = New.self
commandTree["add-to-bin"] = AddToBin.self

// MARK: Execution

var iterator = Process.arguments.makeIterator()

guard let directory = iterator.next() else {
  fail("no directory")
}
guard let commandKey = iterator.next() else {
  fail("no command")
}
guard let command = commandTree[commandKey] else {
  fail("command \(commandKey) doesn't exist")
}

let arguments = Array(iterator)

command.execute(with: arguments, in: directory)

Template: https://gist.github.com/LoganWright/899acec46512a966653206f5dcc27d2a