// Take a look at the license at the top of the repository in the LICENSE file.

#[cfg(feature = "user")]

pub(crate) fn cstr_to_rust(c: *const libc::c_char) -> Option<String> {

    cstr_to_rust_with_size(c, None)

}

#[cfg(any(feature = "disk", feature = "system", feature = "user"))]

#[allow(dead_code)]

pub(crate) fn cstr_to_rust_with_size(

    c: *const libc::c_char,

    size: Option<usize>,

) -> Option<String> {

    if c.is_null() {

        return None;

    }

    let (mut s, max) = match size {

        Some(len) => (Vec::with_capacity(len), len as isize),

        None => (Vec::new(), isize::MAX),

    };

    let mut i = 0;

    unsafe {

        loop {

            let value = *c.offset(i) as u8;

            if value == 0 {

                break;

            }

            s.push(value);

            i += 1;

            if i >= max {

                break;

            }

        }

        String::from_utf8(s).ok()

    }

}

#[cfg(all(

    feature = "system",

    not(any(

        target_os = "ios",

        all(target_os = "macos", feature = "apple-sandbox",)

    ))

))]

pub(crate) fn wait_process(pid: crate::Pid) -> Option<std::process::ExitStatus> {

    use std::os::unix::process::ExitStatusExt;

    let mut status = 0;

    // attempt waiting

    unsafe {

        if retry_eintr!(libc::waitpid(pid.0, &mut status, 0)) < 0 {

            // attempt failed (non-child process) so loop until process ends

            let duration = std::time::Duration::from_millis(10);

            while libc::kill(pid.0, 0) == 0 {

                std::thread::sleep(duration);

            }

        }

        Some(std::process::ExitStatus::from_raw(status))

    }

}