在 Swift 中，如何查看 Process() 传递给 shell 的字符串

我试图使用Process()在Swift中启动一个任务，但我需要查看为了调试目的发送到shell的内容.

我正在try 发送以下命令:

gswin64c.exe -q -dNODISPLAY -dNOSAFER -c "(input.pdf) (r) file runpdfbegin pdfpagecount = quit"

如果我在使用UNIX shell(bash、zsh等)的环境中运行相同的命令，那么它运行良好.在Windows中使用cmd.但是，它失败，并给出以下错误消息:

Error: /undefined in ".

我怀疑Swift 正在插入斜杠作为"转义"字符.有没有办法查看Swift发送到shell的字符串？

以下是一个示例:

import Foundation

let inputFile = URL(fileURLWithPath: "input.pdf")
let task = Process()

// In MacOS or Linux, obviously, we would use the appropriate path to 'gs'.
// Use gswin32c.exe if you have the 32-bit version of Ghostscript in Windows.
task.executableURL = URL(fileURLWithPath: #"C:\Program Files\gs\gs9.56.1\bin\gswin64c.exe"#)

// The following works when the shell is bash, zsh, or similar, but not with cmd
task.arguments = ["-q",
                  "-dNODISPLAY",
                  "-dNOSAFER",
                  "-c",
                  "\"(\(inputFile.path)) (r) file runpdfbegin pdfpagecount = quit\""]

let stdout = Pipe()
let stderr = Pipe()
task.standardOutput = stdout
task.standardError = stderr

do {
    try task.run()
} catch {
    print(error)
    exit(1)
}

task.waitUntilExit()

extension String {
    init?(pipe: Pipe) {
        guard let data = try? pipe.fileHandleForReading.readToEnd() else {
            return nil
        }
        
        guard let result = String(data: data, encoding: .utf8) else {
            return nil
        }
        
        self = result
    }
}

if let stdoutText = String(pipe: stdout) {
    print(stdoutText)
}

if let stderrText = String(pipe: stderr) {
    print(stderrText)
}

接下来，该命令是否可以用Swift编写，以便正确地传递给GhostScript？

跟进:

似乎没有一种直接的方法可以看出Swift 向壳牌发送了什么.

然而，我还是解决了眼前的问题.似乎是将代码发送到Windows命令shell的消毒剂在空格前插入了斜杠.我可以通过删除PostScript指令两侧的引号(事实证明它们不是必需的)并将每个元素放置在数组的一个单独成员中来解决这个问题:

task.arguments = [ "-q",
               "-dNODISPLAY",
               "-dNOSAFER",
               "-c",
               "(\(inputFile.path))",
               "(r)",
               "file",
               "runpdfbegin",
               "pdfpagecount",
               "=",
               "quit" ]

或者，如果您希望看到整个工作示例:

import Foundation

let inputFile = URL(fileURLWithPath: "input.pdf")
let task = Process()

// In MacOS or Linux, obviously, we would use the appropriate path to 'gs'.
// Use gswin32c.exe if you have the 32-bit version of Ghostscript in Windows.
task.executableURL = URL(fileURLWithPath: #"C:\Program Files\gs\gs9.56.1\bin\gswin64c.exe"#)

print(inputFile.path)

task.arguments = [ "-q",
                   "-dNODISPLAY",
                   "-dNOSAFER",
                   "-c",
                   "(\(inputFile.path))",
                   "(r)",
                   "file",
                   "runpdfbegin",
                   "pdfpagecount",
                   "=",
                   "quit" ]

let stdout = Pipe()
let stderr = Pipe()
task.standardOutput = stdout
task.standardError = stderr

do {
    try task.run()
} catch {
    print(error)
    exit(1)
}

task.waitUntilExit()

extension String {
    init?(pipe: Pipe) {
        guard let data = try? pipe.fileHandleForReading.readToEnd() else {
            return nil
        }
        
        guard let result = String(data: data, encoding: .utf8) else {
            return nil
        }
        
        self = result
    }
}

if let stdoutText = String(pipe: stdout) {
    print(stdoutText)
}

if let stderrText = String(pipe: stderr) {
    print(stderrText)
}