Function evcxr::runtime_hook

source · 
pub fn runtime_hook()
Expand description

Binaries can call this just after staring. If we detect that we’re actually running as a subprocess, control will not return. There are two kinds of subprocesses that we may be acting as (1) the process that loads and runs the user code and (2) a wrapper around rustc.

Examples found in repository?
examples/example_eval.rs (line 14)
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fn main() -> Result<(), Error> {
    // You must call ```evcxr::runtime_hook()``` at the top of main, otherwise
    // the library becomes a fork-bomb.
    evcxr::runtime_hook();

    let (mut context, outputs) = EvalContext::new()?;
    context.eval("let mut s = String::new();")?;
    context.eval(r#"s.push_str("Hello, ");"#)?;
    context.eval(r#"s.push_str("World!");"#)?;
    context.eval(r#"println!("{}", s);"#)?;

    // For this trivial example, we just receive a single line of output from
    // the code that was run. In a more complex case, we'd likely want to have
    // separate threads waiting for output on both stdout and stderr.
    if let Ok(line) = outputs.stdout.recv() {
        println!("{line}");
    }

    Ok(())
}