Process.start：如何获得输出？

时间：2010-11-27 13:42:02

标签： c# .net mono process.start

我想从我的Mono / .NET应用程序运行外部命令行程序。 例如，我想运行 mencoder 。有可能：

  1. 要获取命令行shell输出，并将其写在我的文本框中？
  2. 要获取数值以显示经过时间的进度条吗？

11 个答案:

答案 0 :(得分：393)

适当地创建Process对象集StartInfo时：

var proc = new Process 
{
    StartInfo = new ProcessStartInfo
    {
        FileName = "program.exe",
        Arguments = "command line arguments to your executable",
        UseShellExecute = false,
        RedirectStandardOutput = true,
        CreateNoWindow = true
    }
};

然后开始这个过程并从中读取：

proc.Start();
while (!proc.StandardOutput.EndOfStream)
{
    string line = proc.StandardOutput.ReadLine();
    // do something with line
}

您可以使用int.Parse()或int.TryParse()将字符串转换为数字值。如果您读取的字符串中包含无效的数字字符，则可能必须先进行一些字符串操作。

答案 1 :(得分：209)

您可以同步处理输出 或异步。

1：同步示例 

static void runCommand()
{
    Process process = new Process();
    process.StartInfo.FileName = "cmd.exe";
    process.StartInfo.Arguments = "/c DIR"; // Note the /c command (*)
    process.StartInfo.UseShellExecute = false;
    process.StartInfo.RedirectStandardOutput = true;
    process.StartInfo.RedirectStandardError = true;
    process.Start();
    //* Read the output (or the error)
    string output = process.StandardOutput.ReadToEnd();
    Console.WriteLine(output);
    string err = process.StandardError.ReadToEnd();
    Console.WriteLine(err);
    process.WaitForExit();
}

注意，处理输出和错误会更好：它们必须单独处理。

（*）对于某些命令（此处为StartInfo.Arguments），您必须添加/c directive，否则该过程会冻结WaitForExit()。

2：异步示例 

static void runCommand() 
{
    //* Create your Process
    Process process = new Process();
    process.StartInfo.FileName = "cmd.exe";
    process.StartInfo.Arguments = "/c DIR";
    process.StartInfo.UseShellExecute = false;
    process.StartInfo.RedirectStandardOutput = true;
    process.StartInfo.RedirectStandardError = true;
    //* Set your output and error (asynchronous) handlers
    process.OutputDataReceived += new DataReceivedEventHandler(OutputHandler);
    process.ErrorDataReceived += new DataReceivedEventHandler(OutputHandler);
    //* Start process and handlers
    process.Start();
    process.BeginOutputReadLine();
    process.BeginErrorReadLine();
    process.WaitForExit();
}

static void OutputHandler(object sendingProcess, DataReceivedEventArgs outLine) 
{
    //* Do your stuff with the output (write to console/log/StringBuilder)
    Console.WriteLine(outLine.Data);
}

如果您不需要对输出进行复杂的操作，可以绕过OutputHandler方法，只需直接添加处理程序：

//* Set your output and error (asynchronous) handlers
process.OutputDataReceived += (s, e) => Console.WriteLine(e.Data);
process.ErrorDataReceived += (s, e) => Console.WriteLine(e.Data);

答案 2 :(得分：8)

好吧，对于任何想要读错误和输出的人来说，但是在其他答案（比如我）中提供的任何解决方案都会遇到死锁，这是我在阅读标准输出属性的MSDN解释后构建的解决方案。

答案基于T30的代码：

static void runCommand()
{
    //* Create your Process
    Process process = new Process();
    process.StartInfo.FileName = "cmd.exe";
    process.StartInfo.Arguments = "/c DIR";
    process.StartInfo.UseShellExecute = false;
    process.StartInfo.RedirectStandardOutput = true;
    process.StartInfo.RedirectStandardError = true;
    //* Set ONLY ONE handler here.
    process.ErrorDataReceived += new DataReceivedEventHandler(OutputHandler);
    //* Start process
    process.Start();
    //* Read one element asynchronously
    process.BeginErrorReadLine();
    //* Read the other one synchronously
    string output = process.StandardOutput.ReadToEnd();
    Console.WriteLine(output);
    process.WaitForExit();
}

static void OutputHandler(object sendingProcess, DataReceivedEventArgs outLine) 
{
    //* Do your stuff with the output (write to console/log/StringBuilder)
    Console.WriteLine(outLine.Data);
}

答案 3 :(得分：7)

执行此操作的标准.NET方法是从Process {StandardOutput流中读取。链接的MSDN文档中有一个示例。类似地，您可以阅读StandardError，并写信至StandardInput。

答案 4 :(得分：4)

您可以使用共享内存进行通信，请查看MemoryMappedFile

您将主要使用“using”语句在父进程中创建内存映射文件mmf，然后创建第二个进程，直到它终止并让它使用{{mmf将结果写入BinaryWriter 1}}，然后使用父进程从mmf读取结果，您也可以使用命令行参数传递mmf名称或硬编码。

确保在父进程中使用映射文件时，使子进程在父进程中释放映射文件之前将结果写入映射文件

实施例： 父进程

    private static void Main(string[] args)
    {
        using (MemoryMappedFile mmf = MemoryMappedFile.CreateNew("memfile", 128))
        {
            using (MemoryMappedViewStream stream = mmf.CreateViewStream())
            {
                BinaryWriter writer = new BinaryWriter(stream);
                writer.Write(512);
            }

            Console.WriteLine("Starting the child process");
            // Command line args are separated by a space
            Process p = Process.Start("ChildProcess.exe", "memfile");

            Console.WriteLine("Waiting child to die");

            p.WaitForExit();
            Console.WriteLine("Child died");

            using (MemoryMappedViewStream stream = mmf.CreateViewStream())
            {
                BinaryReader reader = new BinaryReader(stream);
                Console.WriteLine("Result:" + reader.ReadInt32());
            }
        }
        Console.WriteLine("Press any key to continue...");
        Console.ReadKey();
    }

子进程

    private static void Main(string[] args)
    {
        Console.WriteLine("Child process started");
        string mmfName = args[0];

        using (MemoryMappedFile mmf = MemoryMappedFile.OpenExisting(mmfName))
        {
            int readValue;
            using (MemoryMappedViewStream stream = mmf.CreateViewStream())
            {
                BinaryReader reader = new BinaryReader(stream);
                Console.WriteLine("child reading: " + (readValue = reader.ReadInt32()));
            }
            using (MemoryMappedViewStream input = mmf.CreateViewStream())
            {
                BinaryWriter writer = new BinaryWriter(input);
                writer.Write(readValue * 2);
            }
        }

        Console.WriteLine("Press any key to continue...");
        Console.ReadKey();
    }

要使用此示例，您需要创建一个包含2个项目的解决方案，然后从％childDir％/ bin / debug获取子进程的构建结果并将其复制到％parentDirectory％/ bin / debug然后运行父项目

childDir和parentDirectory是电脑上项目的文件夹名称 祝你好运：）

答案 5 :(得分：3)

  1. 可以按照此处所述获取流程的命令行shell输出：http://www.c-sharpcorner.com/UploadFile/edwinlima/SystemDiagnosticProcess12052005035444AM/SystemDiagnosticProcess.aspx

  2. 这取决于mencoder。如果它在命令行输出此状态，则是：）

答案 6 :(得分：1)

如何启动进程（例如bat文件，perl脚本，控制台程序）并在Windows窗体上显示其标准输出：

processCaller = new ProcessCaller(this);
//processCaller.FileName = @"..\..\hello.bat";
processCaller.FileName = @"commandline.exe";
processCaller.Arguments = "";
processCaller.StdErrReceived += new DataReceivedHandler(writeStreamInfo);
processCaller.StdOutReceived += new DataReceivedHandler(writeStreamInfo);
processCaller.Completed += new EventHandler(processCompletedOrCanceled);
processCaller.Cancelled += new EventHandler(processCompletedOrCanceled);
// processCaller.Failed += no event handler for this one, yet.

this.richTextBox1.Text = "Started function.  Please stand by.." + Environment.NewLine;

// the following function starts a process and returns immediately,
// thus allowing the form to stay responsive.
processCaller.Start();

您可以在此链接上找到ProcessCaller：Launching a process and displaying its standard output

答案 7 :(得分：0)

在win和linux上对我有用的解决方案是

// GET api/values
        [HttpGet("cifrado/{xml}")]
        public ActionResult<IEnumerable<string>> Cifrado(String xml)
        {
            String nombreXML = DateTime.Now.ToString("ddMMyyyyhhmmss").ToString();
            String archivo = "/app/files/"+nombreXML + ".XML";
            String comando = " --armor --recipient bibankingprd@bi.com.gt  --encrypt " + archivo;
            try{
                System.IO.File.WriteAllText(archivo, xml);                
                //String comando = "C:\\GnuPG\\bin\\gpg.exe --recipient licorera@local.com --armor --encrypt C:\\Users\\Administrador\\Documents\\pruebas\\nuevo.xml ";
                ProcessStartInfo startInfo = new ProcessStartInfo() {FileName = "/usr/bin/gpg",  Arguments = comando }; 
                Process proc = new Process() { StartInfo = startInfo, };
                proc.StartInfo.RedirectStandardOutput = true;
                proc.StartInfo.RedirectStandardError = true;
                proc.Start();
                proc.WaitForExit();
                Console.WriteLine(proc.StandardOutput.ReadToEnd());
                return new string[] { "Archivo encriptado", archivo + " - "+ comando};
            }catch (Exception exception){
                return new string[] { archivo, "exception: "+exception.ToString() + " - "+ comando };
            }
        }

答案 8 :(得分：0)

我在调用 Process.StandardOutput.ReadLine 和 Process.StandardOutput.ReadToEnd 时遇到了臭名昭著的死锁问题。

我的目标/用例很简单。启动一个进程并重定向它的输出，以便我可以捕获该输出并将其通过 .NET Core 的 ILogger<T> 记录到控制台，并将重定向的输出附加到文件日志中。

这是我使用内置异步事件处理程序 Process.OutputDataReceived 和 Process.ErrorDataReceived 的解决方案。

var p = new Process
{
    StartInfo = new ProcessStartInfo(
        command.FileName, command.Arguments
    )
    {
        RedirectStandardOutput = true,
        RedirectStandardError = true,
        UseShellExecute = false,
    }
};


// Asynchronously pushes StdOut and StdErr lines to a thread safe FIFO queue
var logQueue = new ConcurrentQueue<string>();
p.OutputDataReceived += (sender, args) => logQueue.Enqueue(args.Data);
p.ErrorDataReceived += (sender, args) => logQueue.Enqueue(args.Data);

// Start the process and begin streaming StdOut/StdErr
p.Start();
p.BeginOutputReadLine();
p.BeginErrorReadLine();

// Loop until the process has exited or the CancellationToken is triggered
do
{
    var lines = new List<string>();
    while (logQueue.TryDequeue(out var log))
    {
        lines.Add(log);
        _logger.LogInformation(log)
    }
    File.AppendAllLines(_logFilePath, lines);

    // Asynchronously sleep for some time
    try
    {
        Task.Delay(5000, stoppingToken).Wait(stoppingToken);
    }
    catch(OperationCanceledException) {}

} while (!p.HasExited && !stoppingToken.IsCancellationRequested);

答案 9 :(得分：0)

System.Diagnostics.Process 使用起来不是很愉快，因此您可能想尝试 CliWrap。它提供了许多不同的输出模型，包括管道、缓冲和实时流。以下是一些示例（摘自自述文件）。

只需启动一个命令行可执行文件：

using CliWrap;

var result = await Cli.Wrap("path/to/exe")
    .WithArguments("--foo bar")
    .WithWorkingDirectory("work/dir/path")
    .ExecuteAsync();
    
// Result contains:
// -- result.ExitCode        (int)
// -- result.StartTime       (DateTimeOffset)
// -- result.ExitTime        (DateTimeOffset)
// -- result.RunTime         (TimeSpan)

启动命令行可执行文件并在内存中缓冲 stdout/stderr：

using CliWrap;
using CliWrap.Buffered;

// Calling `ExecuteBufferedAsync()` instead of `ExecuteAsync()`
// implicitly configures pipes that write to in-memory buffers.
var result = await Cli.Wrap("path/to/exe")
    .WithArguments("--foo bar")
    .WithWorkingDirectory("work/dir/path")
    .ExecuteBufferedAsync();

// Result contains:
// -- result.StandardOutput  (string)
// -- result.StandardError   (string)
// -- result.ExitCode        (int)
// -- result.StartTime       (DateTimeOffset)
// -- result.ExitTime        (DateTimeOffset)
// -- result.RunTime         (TimeSpan)

使用手动管道配置启动命令行可执行文件：

using CliWrap

var buffer = new StringBuilder();

var result = await Cli.Wrap("foo")
    .WithStandardOutputPipe(PipeTarget.ToFile("output.txt"))
    .WithStandardErrorPipe(PipeTarget.ToStringBuilder(buffer))
    .ExecuteAsync();

启动一个命令行可执行文件作为事件流：

using CliWrap;
using CliWrap.EventStream;

var cmd = Cli.Wrap("foo").WithArguments("bar");

await foreach (var cmdEvent in cmd.ListenAsync())
{
    switch (cmdEvent)
    {
        case StartedCommandEvent started:
            _output.WriteLine($"Process started; ID: {started.ProcessId}");
            break;
        case StandardOutputCommandEvent stdOut:
            _output.WriteLine($"Out> {stdOut.Text}");
            break;
        case StandardErrorCommandEvent stdErr:
            _output.WriteLine($"Err> {stdErr.Text}");
            break;
        case ExitedCommandEvent exited:
            _output.WriteLine($"Process exited; Code: {exited.ExitCode}");
            break;
    }
}

答案 10 :(得分：-1)

您可以使用以下代码记录过程输出：

ProcessStartInfo pinfo = new ProcessStartInfo(item);
pinfo.CreateNoWindow = false;
pinfo.UseShellExecute = true;
pinfo.RedirectStandardOutput = true;
pinfo.RedirectStandardInput = true;
pinfo.RedirectStandardError = true;
pinfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Normal;
var p = Process.Start(pinfo);
p.WaitForExit();
Process process = Process.Start(new ProcessStartInfo((item + '>' + item + ".txt"))
{
    UseShellExecute = false,
    RedirectStandardOutput = true
});
process.WaitForExit();
string output = process.StandardOutput.ReadToEnd();
if (process.ExitCode != 0) { 
}
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