Asmichi.ChildProcess 0.2.0

Asmichi.ChildProcess

A .NET library that provides functionality for creating child processes. Easier, less error-prone, more flexible than System.Diagnostics.Process at creating child processes.

This library can be obtained via NuGet.

Comparison with System.Diagnostics.Process

• Concentrates on creating a child process and obtaining its output.
  • Cannot query status of a process.
• More destinations of redirection:
  • NUL
  • File (optionally appended)
  • Pipe
  • Handle
• Less error-prone default values for redirection:
  • stdin to NUL
  • stdout to the current stdout
  • stderr to the current stderr
• Pipes are asynchronous; asynchronous reads and writes will be handled by IO completion ports.
• WaitForExitAsync.

License

The MIT License

Supported Runtimes

• .NET Core 3.1 or later

OS:

• win10-x86 (1803 or later)
• win10-x64 (1803 or later)
• linux-x64
  • GLIBC 2.x.y or later, LIBSTDCXX 3.x.y or later.
  • (Alpine Linux is not currently supported.)

Notes

• When overriding environment variables, it is recommended that you include basic environment variables such as SystemRoot, etc.

Assumptions on Runtimes

This library assumes that the underlying runtime has the following characteristics:

• Windows
  • The inner value of a SafeFileHandle is a file handle.
  • The inner value of a SafeWaitHandle is a handle that WaitForSingleObject can wait for.
  • The inner value of a SafeProcessHandle is a process handle.
• *nix
  • The inner value of a SafeFileHandle is a file descriptor.
  • The inner value of a SafeProcessHandle is a process id.
  • Socket.Handle returns a socket file descriptor.

Limitations

• More than 2^63 processes cannot be created.

Examples

See ChildProcess.Example for more examples.

Basic

var si = new ChildProcessStartInfo("cmd", "/C", "echo", "foo")
{
    StdOutputRedirection = OutputRedirection.OutputPipe,
};

using (var p = ChildProcess.Start(si))
{
    using (var sr = new StreamReader(p.StandardOutput))
    {
        // "foo"
        Console.Write(await sr.ReadToEndAsync());
    }
    await p.WaitForExitAsync();
    // ExitCode: 0
    Console.WriteLine("ExitCode: {0}", p.ExitCode);
}

Redirection to File

var si = new ChildProcessStartInfo("cmd", "/C", "set")
{
    StdOutputRedirection = OutputRedirection.File,
    StdOutputFile = "env.txt"
};

using (var p = ChildProcess.Start(si))
{
    await p.WaitForExitAsync();
}

// ALLUSERSPROFILE=C:\ProgramData
// ...
Console.WriteLine(File.ReadAllText("env.txt"));