如何为进程设置环境变量？

Question

复制自How do I run an terminal command in a swift script? (e.g. xcodebuild)：

import Foundation

@discardableResult
func shell(_ args: String...) -> Int32 {
    let task = Process()
    task.launchPath = "/usr/bin/env"
    task.arguments = args
    task.launch()
    task.waitUntilExit()
    return task.terminationStatus
}

shell("ls")
shell("xcodebuild", "-workspace", "myApp.xcworkspace")

这看起来很整洁。我只是想知道如何为进程设置像$PWD 这样的环境变量（这里命名为task ...）。

---

我尝试了以下方法：

import Foundation

@discardableResult
func execCommand(_ args: String...) -> Int32 {
    let process = Process()
    process.launchPath = "/usr/bin/env"
    process.environment = ["PWD": "/Users"]
    if let env = process.environment {
        print(env["PWD"] ?? "Unknown")
    } else {
        print("Environment not available!")
    }
    process.arguments = args
    process.launch()
    process.waitUntilExit()
    return process.terminationStatus
}


execCommand("pwd")

并打印了这些行：

/Users
/private/tmp/AppIcon.appiconset

显然已经设置了环境变量，但是对pwd命令完全没有影响。

---

另一种方法：

import Foundation

@discardableResult
func execCommand(_ args: String...) -> Int32 {
    let process = Process()
    process.launchPath = "/usr/bin/env"
    var environment = ProcessInfo.processInfo.environment
    environment["PWD"] = "/Users" //optionally set new vars, or overwrite old ones
    process.environment = environment
    if let env = process.environment {
        print(env["PWD"] ?? "Unknown")
    } else {
        print("Environment not available!")
    }
    process.arguments = args
    process.launch()
    process.waitUntilExit()
    return process.terminationStatus
}


execCommand("pwd")

不幸的是，结果和以前一样。

Answer 1

您只需将Process 的environment 变量设置为包含变量到值映射的[String: String]。

let process = Process()
// ...
process.environment = ["home": "/Users/foo"]

如果你想传递当前环境，你可以这样做：

let process = Process()
// ...
let environment = ProcessInfo.processInfo.environment
environment["home"] = "/Users/foo" //optionally set new vars, or overwrite old ones
process.environment = environment

如果你想设置工作目录，这不是由环境变量决定的，而是通过currentDirectoryPath property。

let process = Process()
// ...
process.currentDirectoryPath = "/Users"