Return Result of an IF executed by the Command Prompt (CMD) in C #

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Return Result of an IF executed by the Command Prompt (CMD) in C #

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#1 by (1 votes)

1

Hello, I'm trying to get a return from an IF line of the Command Prompt (CMD) with Visual Studio 2015 in C #, but I'm not getting it.

The following code executes the CMD, inserts the directory path containing a C ++ (.cpp) file, and using the MinGW compiler, compiles and generates the executable (.exe) or error message occurs. Using IF EXIST, confirm whether the executable was created or not. But the return of the IF that indicates if the file was found or not found, not being able to return the result in which it will be used in a variable that will be validated in the future.

using System;
using System.Windows.Forms;
using System.Diagnostics;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void btnExecutar_Click(object sender, EventArgs e)
        {            
            string aspasDuplas = lblAspasDuplas.Text;
            string retornar;

            ProcessStartInfo processStartInfo = new ProcessStartInfo("cmd.exe");
            processStartInfo.RedirectStandardInput = true;
            processStartInfo.RedirectStandardOutput = true;
            processStartInfo.UseShellExecute = false;
            processStartInfo.CreateNoWindow = true; // Não mostrar janela do cmd        

            Process process = Process.Start(processStartInfo);
            process.StandardInput.WriteLine(@"cd C:\Users\Desktop\ConsoleApplication1\ConsoleApplication1");
            process.StandardInput.WriteLine(@"g++ -o Source Source.cpp");
            process.StandardInput.WriteLine(@"IF EXIST " + aspasDuplas + "Source.exe" + aspasDuplas + " (ECHO found) ELSE (ECHO not found)");

            retornar = process.StandardOutput.ReadLine();

            process.StandardInput.WriteLine(@"exit");
            process.WaitForExit(); // espera o cmd.exe terminar

            txtRetorno.Text = retornar;
        }
    }
}

But your Return text is Always:

Microsoft Windows [versÆo 10.0.16299.248]

Use the ReadToEnd command instead of ReadLine:

Process process = Process.Start(processStartInfo);
process.StandardInput.WriteLine(@"cd C:\Users\Desktop\ConsoleApplication1\ConsoleApplication1");
process.StandardInput.WriteLine(@"g++ -o Source Source.cpp");
process.StandardInput.WriteLine(@"IF EXIST " + aspasDuplas + "Source.exe" + aspasDuplas + " (ECHO found) ELSE (ECHO not found)");            
process.StandardInput.WriteLine(@"exit");

retornar = process.StandardOutput.ReadToEnd();

process.WaitForExit(); // espera o cmd.exe terminar

txtRetorno.Text = retornar;

But your return is all CMD writing:

Microsoft Windows [versÆo 10.0.16299.248]
(c) 2017 Microsoft Corporation. Todos os direitos reservados.

C:\Users\Desktop\WindowsFormsApplication1\WindowsFormsApplication1\bin\Debug>cd C:\Users\Desktop\ConsoleApplication1\ConsoleApplication1

C:\Users\Desktop\ConsoleApplication1\ConsoleApplication1>g++ -o Source Source.cpp

C:\Users\Desktop\ConsoleApplication1\ConsoleApplication1>IF EXIST "Source.exe" (ECHO found) ELSE (ECHO not found)
not found

C:\Users\Desktop\ConsoleApplication1\ConsoleApplication1>exit

If someone can help me get only the IF return (found or not found). Thank you in advance for those who help.

c# cmd return visual-studio-2015 prompt

asked by anonymous 29.08.2018 / 14:59

1 answer

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score 1 · Accepted Answer

Instead of validating for IF of the file exists, you can always remove it after the process terminates if:

// espera o cmd.exe terminar
process.WaitForExit();

string strFile = @"C:\Users\Desktop\ConsoleApplication1\ConsoleApplication1\Source.exe";

if(File.Exists(strFile)
    File.Delete(strFile);

Refactored code:

private void btnExecutar_Click(object sender, EventArgs e)
{
    string strPasta = @"C:\Users\Desktop\ConsoleApplication1\ConsoleApplication1";
    string strFicheiro = $"{strPasta}\Source.exe";
    string retornar = string.Empty;

    try
    {
        ProcessStartInfo processStartInfo = new ProcessStartInfo("cmd.exe")
        {
            RedirectStandardInput = true,
            RedirectStandardOutput = true,
            UseShellExecute = false,
            CreateNoWindow = true
        };

        Process process = Process.Start(processStartInfo);

        process.StandardInput.WriteLine($"cd {strPasta}");
        process.StandardInput.WriteLine("g++ -o Source Source.cpp");

        retornar = process.StandardOutput.ReadLine();

        process.StandardInput.WriteLine("exit");
        process.WaitForExit();
    }
    catch (Exception ex)
    {
        throw ex;
    }
    finally
    {
        if (File.Exists(strFicheiro))
            File.Delete(strFicheiro);

        txtRetorno.Text = retornar;
    }
}