操作方法:在C#中执行命令行,获取STD OUT结果

Question

如何从C#执行命令行程序并返回STD OUT结果.具体来说,我想对以编程方式选择的两个文件执行DIFF,并将结果写入文本框.是的,我可以为自己解决这个问题,但肯定有人做过类似的事情,我很懒...

Answer 1

// Start the child process.
 Process p = new Process();
 // Redirect the output stream of the child process.
 p.StartInfo.UseShellExecute = false;
 p.StartInfo.RedirectStandardOutput = true;
 p.StartInfo.FileName = "YOURBATCHFILE.bat";
 p.Start();
 // Do not wait for the child process to exit before
 // reading to the end of its redirected stream.
 // p.WaitForExit();
 // Read the output stream first and then wait.
 string output = p.StandardOutput.ReadToEnd();
 p.WaitForExit();

代码来自MSDN.

Answer 2

这是一个快速示例:

//Create process
System.Diagnostics.Process pProcess = new System.Diagnostics.Process();

//strCommand is path and file name of command to run
pProcess.StartInfo.FileName = strCommand;

//strCommandParameters are parameters to pass to program
pProcess.StartInfo.Arguments = strCommandParameters;

pProcess.StartInfo.UseShellExecute = false;

//Set output of program to be written to process output stream
pProcess.StartInfo.RedirectStandardOutput = true;   

//Optional
pProcess.StartInfo.WorkingDirectory = strWorkingDirectory;

//Start the process
pProcess.Start();

//Get program output
string strOutput = pProcess.StandardOutput.ReadToEnd();

//Wait for process to finish
pProcess.WaitForExit();

Answer 3

还有一个我发现有用的参数,我用它来消除进程窗口

pProcess.StartInfo.CreateNoWindow = true;

这有助于完全隐藏黑色控制台窗口,如果这是你想要的.

Answer 4

// usage
const string ToolFileName = "example.exe";
string output = RunExternalExe(ToolFileName);

public string RunExternalExe(string filename, string arguments = null)
{
    var process = new Process();

    process.StartInfo.FileName = filename;
    if (!string.IsNullOrEmpty(arguments))
    {
        process.StartInfo.Arguments = arguments;
    }

    process.StartInfo.CreateNoWindow = true;
    process.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
    process.StartInfo.UseShellExecute = false;

    process.StartInfo.RedirectStandardError = true;
    process.StartInfo.RedirectStandardOutput = true;
    var stdOutput = new StringBuilder();
    process.OutputDataReceived += (sender, args) => stdOutput.AppendLine(args.Data); // Use AppendLine rather than Append since args.Data is one line of output, not including the newline character.

    string stdError = null;
    try
    {
        process.Start();
        process.BeginOutputReadLine();
        stdError = process.StandardError.ReadToEnd();
        process.WaitForExit();
    }
    catch (Exception e)
    {
        throw new Exception("OS error while executing " + Format(filename, arguments)+ ": " + e.Message, e);
    }

    if (process.ExitCode == 0)
    {
        return stdOutput.ToString();
    }
    else
    {
        var message = new StringBuilder();

        if (!string.IsNullOrEmpty(stdError))
        {
            message.AppendLine(stdError);
        }

        if (stdOutput.Length != 0)
        {
            message.AppendLine("Std output:");
            message.AppendLine(stdOutput.ToString());
        }

        throw new Exception(Format(filename, arguments) + " finished with exit code = " + process.ExitCode + ": " + message);
    }
}

private string Format(string filename, string arguments)
{
    return "'" + filename + 
        ((string.IsNullOrEmpty(arguments)) ? string.Empty : " " + arguments) +
        "'";
}

Answer 5

 System.Diagnostics.ProcessStartInfo psi =
   new System.Diagnostics.ProcessStartInfo(@"program_to_call.exe");
 psi.RedirectStandardOutput = true;
 psi.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
 psi.UseShellExecute = false;
 System.Diagnostics.Process proc System.Diagnostics.Process.Start(psi);;
 System.IO.StreamReader myOutput = proc.StandardOutput;
 proc.WaitForExit(2000);
 if (proc.HasExited)
  {
  string output = myOutput.ReadToEnd();
 }

Answer 6

此页面上接受的答案有一个在极少数情况下很麻烦的弱点.有两个文件句柄,程序按惯例,stdout和stderr写入.如果您只是读取单个文件句柄(例如Ray的答案),并且您正在开始的程序将足够的输出写入stderr,它将填充输出stderr缓冲区并阻塞.然后你的两个进程陷入僵局.缓冲区大小可以是4K.这在短期程序中极为罕见,但如果你有一个长期运行的程序,它反复输出到stderr,它最终会发生.调试和跟踪这很棘手.

有几种很好的方法可以解决这个问题.

1. 一种方法是执行cmd.exe而不是程序,并使用cmd.exe的/ c参数调用程序以及cmd.exe的"2>&1"参数,告诉它合并stdout和stderr.

           var p = new Process();
           p.StartInfo.FileName = "cmd.exe";
           p.StartInfo.Arguments = "/c mycmd.exe 2>&1";
   

2. 另一种方法是使用一个同时读取两个句柄的编程模型.

           var p = new Process();
           p.StartInfo.FileName = "cmd.exe";
           p.StartInfo.Arguments = @"/c dir \windows";
           p.StartInfo.CreateNoWindow = true;
           p.StartInfo.RedirectStandardError = true;
           p.StartInfo.RedirectStandardOutput = true;
           p.StartInfo.RedirectStandardInput = false;
           p.OutputDataReceived += (a, b) => Console.WriteLine(b.Data);
           p.ErrorDataReceived += (a, b) => Console.WriteLine(b.Data);
           p.Start();
           p.BeginErrorReadLine();
           p.BeginOutputReadLine();
           p.WaitForExit();
   

Answer 7

您将需要使用ProcessStartInfo与RedirectStandardOutput启用-那么你可以读取输出流.您可能会发现使用">"将输出重定向到文件(通过操作系统)更容易,然后只需读取文件即可.

[编辑:像雷一样:+1]

Answer 8

如果您不介意引入依赖项，CliWrap可以为您简化：

using CliWrap;
using CliWrap.Buffered;

var result = await Cli.Wrap("target.exe")
   .WithArguments("arguments")
   .ExecuteBufferedAsync();

var stdout = result.StandardOutput;

Answer 9

由于这里的大多数答案都没有实现using声明IDisposable以及我认为可能有必要的其他一些内容，因此我将添加这个答案。

对于 C# 8.0

// Start a process with the filename or path with filename e.g. "cmd". Please note the 
//using statemant
using myProcess.StartInfo.FileName = "cmd";
// add the arguments - Note add "/c" if you want to carry out tge  argument in cmd and  
// terminate
myProcess.StartInfo.Arguments = "/c dir";
// Allows to raise events
myProcess.EnableRaisingEvents = true;
//hosted by the application itself to not open a black cmd window
myProcess.StartInfo.UseShellExecute = false;
myProcess.StartInfo.CreateNoWindow = true;
// Eventhander for data
myProcess.Exited += OnOutputDataRecived;
// Eventhandler for error
myProcess.ErrorDataReceived += OnErrorDataReceived;
// Eventhandler wich fires when exited
myProcess.Exited += OnExited;
// Starts the process
myProcess.Start();
//read the output before you wait for exit
myProcess.BeginOutputReadLine();
// wait for the finish - this will block (leave this out if you dont want to wait for 
// it, so it runs without blocking)
process.WaitForExit();

// Handle the dataevent
private void OnOutputDataRecived(object sender, DataReceivedEventArgs e)
{
    //do something with your data
    Trace.WriteLine(e.Data);
}

//Handle the error
private void OnErrorDataReceived(object sender, DataReceivedEventArgs e)
{        
    Trace.WriteLine(e.Data);
    //do something with your exception
    throw new Exception();
}    

// Handle Exited event and display process information.
private void OnExited(object sender, System.EventArgs e)
{
     Trace.WriteLine("Process exited");
}

Answer 10

这是一个小例子：

using System;
using System.Diagnostics;

class Program
{
    static void Main(string[] args)
    {
        var p = Process.Start(
            new ProcessStartInfo("git", "branch --show-current")
            {
                CreateNoWindow = true,
                UseShellExecute = false,
                RedirectStandardError = true,
                RedirectStandardOutput = true,
                WorkingDirectory = Environment.CurrentDirectory
            }
        );

        p.WaitForExit();
        string branchName =p.StandardOutput.ReadToEnd().TrimEnd();
        string errorInfoIfAny =p.StandardError.ReadToEnd().TrimEnd();

        if (errorInfoIfAny.Length != 0)
        {
            Console.WriteLine($"error: {errorInfoIfAny}");
        }
        else { 
            Console.WriteLine($"branch: {branchName}");
        }

    }
}

我相信这是最短的形式。

请注意，大多数命令行工具很容易混淆标准输出和标准错误，有时将它们组合成单个字符串是有意义的。

有时也p.ExitCode可能有用。

如果您想自己编写命令行实用程序（例如工具），上面的示例可用于编写命令行实用程序。请注意，对于 cli 自动化，还可以使用Cake Frosten和Cake Git 扩展。

Answer 11

一行运行命令：

new Process() { StartInfo = new ProcessStartInfo("echo", "Hello, World") }.Start();

以最短的可读代码读取命令的输出：

    var cliProcess = new Process() {
        StartInfo = new ProcessStartInfo("echo", "Hello, World") {
            UseShellExecute = false,
            RedirectStandardOutput = true
        }
    };
    cliProcess.Start();
    string cliOut = cliProcess.StandardOutput.ReadToEnd();
    cliProcess.WaitForExit();
    cliProcess.Close();

Answer 12

如果您还需要在cmd.exe中执行某些命令，您可以执行以下操作：

// Start the child process.
Process p = new Process();
// Redirect the output stream of the child process.
p.StartInfo.UseShellExecute = false;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.FileName = "cmd.exe";
p.StartInfo.Arguments = "/C vol";
p.Start();
// Read the output stream first and then wait.
string output = p.StandardOutput.ReadToEnd();
p.WaitForExit();
Console.WriteLine(output);

这仅返回命令本身的输出：

您还可以使用StandardInput代替StartInfo.Arguments：

// Start the child process.
Process p = new Process();
// Redirect the output stream of the child process.
p.StartInfo.UseShellExecute = false;
p.StartInfo.RedirectStandardInput = true;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.FileName = "cmd.exe";
p.Start();
// Read the output stream first and then wait.
p.StandardInput.WriteLine("vol");
p.StandardInput.WriteLine("exit");
string output = p.StandardOutput.ReadToEnd();
p.WaitForExit();
Console.WriteLine(output);

结果如下：