Process.start：如何獲得輸出？

Question

我想從我的 Mono/.NET 應用程序運行外部命令行程序。 例如，我想運行mencoder 。 是否可以：

1. 要獲取命令行 shell 輸出，並將其寫在我的文本框中？
2. 要獲取數值以顯示經過時間的進度條？

Answer 1

當您適當地創建Process對象集StartInfo ：

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

然后啟動該過程並從中讀取：

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()將字符串轉換為數值。 如果您讀取的字符串中存在無效數字字符，您可能需要先進行一些字符串操作。

Answer 2

您可以同步或異步處理您的輸出。

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();
}

請注意，最好同時處理輸出和錯誤：它們必須分開處理。

(*) 對於某些命令（此處為StartInfo.Arguments ），您必須添加/c指令，否則進程會在WaitForExit()中凍結。

2. 異步示例

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);
}

如果你不需要對輸出做復雜的操作，你可以繞過 OutputHandler 方法，只需直接內聯添加處理程序：

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

Answer 3

好的，對於那些想要同時讀取錯誤和輸出但在其他答案中提供的任何解決方案（如我）陷入僵局的人來說，這是我在閱讀 MSDN 對StandardOutput屬性的解釋后構建的解決方案。

答案基於 T30 的代碼：

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

Answer 4

執行此操作的標准 .NET 方法是從 Process 的StandardOutput流中讀取。 鏈接的 MSDN 文檔中有一個示例。 類似地，您可以從StandardError讀取，並寫入StandardInput 。

Answer 5

1. 可以獲得進程的命令行 shell 輸出，如下所述： http : //www.c-sharpcorner.com/UploadFile/edwinlima/SystemDiagnosticProcess12052005035444AM/SystemDiagnosticProcess.aspx

2. 這取決於mencoder。 如果它在命令行上輸出此狀態，則是 :)

Answer 6

您可以使用共享內存為 2 個進程進行通信，請查看MemoryMappedFile

您將主要使用“using”語句在父進程中創建一個內存映射文件mmf然后創建第二個進程直到它終止並讓它使用BinaryWriter將結果寫入mmf ，然后使用父進程從mmf讀取結果，您還可以使用命令行參數或硬編碼傳遞mmf名稱。

確保在父進程中使用映射文件時，您讓子進程在父進程中釋放映射文件之前將結果寫入映射文件

示例：父進程

    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();
    }

子進程

    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，您需要創建一個包含 2 個項目的解決方案，然后從 %childDir%/bin/debug 獲取子進程的構建結果並將其復制到 %parentDirectory%/bin/debug 然后運行父項目

childDir和parentDirectory是你的項目在電腦上的文件夾名稱祝你好運:)

Answer 7

您可以使用以下代碼記錄進程輸出：

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) { 
}

Answer 8

如何啟動一個進程（例如 bat 文件、perl 腳本、控制台程序）並將其標准輸出顯示在 Windows 窗體上：

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();    

您可以在此鏈接上找到ProcessCaller ： 啟動進程並顯示其標准輸出

Answer 9

在 win 和 linux 中對我有用的解決方案是以下內容

// 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 };
            }
        }

Answer 10

System.Diagnostics.Process並不是最愉快的，因此您可能想嘗試CliWrap 。 它提供了許多不同的輸出模型，包括管道、緩沖和實時流。 以下是一些示例（取自自述文件）。

只需啟動一個命令行可執行文件：

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)

啟動命令行可執行文件並在內存中緩沖 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)

使用手動管道配置啟動命令行可執行文件：

using CliWrap

var buffer = new StringBuilder();

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

以事件流的形式啟動命令行可執行文件：

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;
    }
}

Answer 11

我在調用Process.StandardOutput.ReadLine和Process.StandardOutput.ReadToEnd時遇到了臭名昭著的死鎖問題。

我的目標/用例很簡單。 啟動一個進程並重定向它的輸出，這樣我就可以捕獲該輸出並將其通過 .NET Core 的ILogger<T>記錄到控制台，並將重定向的輸出附加到文件日志中。

這是我使用內置異步事件處理程序Process.OutputDataReceived和Process.ErrorDataReceived解決方案。

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);