How can I detach a child process in C# on Linux so it doesn't terminate with the parent?

When you launch a process on Linux using Process.Start, the child process is started in the same process group as the parent process. When the parent ends, Linux usually sends a hangup (SIGHUP) signal to its entire process group, which causes the child to be terminated as well.

To avoid this, you must detach the child process from the parent’s session. One common solution is to use a shell command that runs the process with nohup (or disowns it) so it won’t be killed when the parent exits. For example, you can start your process like this:

CSHARPCopied
using System.Diagnostics;

var procStartInfo = new ProcessStartInfo
{
    FileName = "/bin/bash",
    Arguments = $"-c \"nohup {program} {arguments} > /dev/null 2>&1 &\"",
    UseShellExecute = false,
    CreateNoWindow = true,
    WorkingDirectory = workingDir
};

Process.Start(procStartInfo);

Explanation

• /bin/bash -c "..."
  By using bash with the -c option, you can execute a command line that uses shell features.

• nohup
  Prevents the process from being terminated when its parent ends (by ignoring the SIGHUP signal).

• Output redirection ( > /dev/null 2>&1 ) &
  Redirects standard output and error, and the trailing ampersand (&) causes the command to run in the background.

Using this approach, the launched process becomes detached from the parent and will continue running even after the parent process exits.