Execute a command in rust and wait for n seconds

help
1

I am using the following to execute a command and then wait to see if it results in a Segmentation Fault. However sometimes the command that gets executed goes in an infinite loop. I need to put a timeout for 5 seconds so that I am not waiting indefinitely.

    let mut put_command = Command::new(program_name).stdin(Stdio::piped()).spawn().unwrap();
    write!(put_command.stdin.as_mut().unwrap(), "{}", inputtext).unwrap();    
    let one_sec = Duration::from_secs(1);
    let status = put_command.wait().unwrap();
    match status.signal() {
        Some(signal) if signal == libc::SIGSEGV => {
            println!("the process resulted in segmentation fault");
        }
        _ => (),
     
    }

I tried using wait_timeout as following:

        let one_sec = Duration::from_secs(1);
        let status = put_command.wait_timeout(one_sec).unwrap();

but I get the following error during compile time:

error[E0599]: no method named `signal` found for enum `Option` in the current scope
  --> src/main.rs:72:22
   |
72 |         match status.signal() {
   |                      ^^^^^^ method not found in `Option<ExitStatus>`

Please advise.

2

Here’s the documentation for the trait method I understand you to be using: https://docs.rs/wait-timeout/latest/wait_timeout/trait.ChildExt.html.

That method returns a std::io::Result<Option<ExitStatus>>. So, you need to handle the possibility of an Err in addition to the Ok containing the Option.

Adding a second unwrap call like this would work for now:

let status = put_command.wait_timeout(one_sec).unwrap().unwrap();

But you should of course consider whether panicking is the best way to handle that case, at some point.

3

status is not of type ExitStatus, it's an Option, you have to handle that.

5

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