Function nc::getpid

source · 
pub unsafe fn getpid() -> pid_t
Expand description

Get the process ID (PID) of the calling process.

§Example

let pid = unsafe { nc::getpid() };
assert!(pid > 0);
Examples found in repository?
examples/prctl.rs (line 16)
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fn main() {
    let process_name = "rust-001";
    let pid = unsafe { nc::getpid() };
    println!("pid: {}, process name: {}", pid, &process_name);
    set_process_name(process_name).unwrap();

    let mask = nc::sigset_t::default();
    let _ret = unsafe { nc::rt_sigsuspend(&mask, size_of::<nc::sigset_t>()) };
}
More examples
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examples/resource_limit.rs (line 8)
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fn get_file_limit() {
    let pid = unsafe { nc::getpid() };
    let mut res_limit = nc::rlimit64_t::default();
    let ret = unsafe { nc::prlimit64(pid, nc::RLIMIT_NOFILE, None, Some(&mut res_limit)) };
    assert!(ret.is_ok());
    if ret.is_err() {
        eprintln!("Failed to get file resource limitation!");
    } else {
        println!(
            "Limit of open files, current: {}, max: {}",
            res_limit.rlim_cur, res_limit.rlim_max
        );
    }
}

fn set_file_limit() {
    let pid = unsafe { nc::getpid() };
    let res_limit = nc::rlimit64_t {
        rlim_cur: 512,
        rlim_max: 1024,
    };
    let ret = unsafe { nc::prlimit64(pid, nc::RLIMIT_NOFILE, Some(&res_limit), None) };
    if ret.is_err() {
        eprintln!("Failed to update file resource limitation!");
    } else {
        println!(
            "Update limit of open files, current: {}, max: {}",
            res_limit.rlim_cur, res_limit.rlim_max
        );
    }
}

fn main() {
    let pid = unsafe { nc::getpid() };
    println!("pid: {}", pid);

    get_file_limit();
    set_file_limit();
    get_file_limit();

    let mask = nc::sigset_t::default();
    let _ret = unsafe { nc::rt_sigsuspend(&mask, size_of::<nc::sigset_t>()) };
}
examples/pidfd.rs (line 27)
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fn run_main() {
    const STDOUT_FD: i32 = 1;

    let pid = unsafe { nc::fork() };
    assert!(pid.is_ok());
    if pid == Ok(0) {
        let curr_pid = unsafe { nc::getpid() };
        println!("In child process, pid: {}", curr_pid);
        let path = "/tmp/nc-pidfdopen";
        let fd = unsafe {
            nc::openat(
                nc::AT_FDCWD,
                path,
                nc::O_CREAT | nc::O_WRONLY | nc::O_TRUNC,
                0o644,
            )
        };
        assert!(fd.is_ok());
        let fd = fd.unwrap();
        let ret = unsafe { nc::dup3(fd, STDOUT_FD, 0) };
        assert!(ret.is_ok());
        println!("[child] stdout redirected to file!");

        let t = nc::timespec_t {
            tv_sec: 2,
            tv_nsec: 0,
        };
        unsafe {
            let ret = nc::nanosleep(&t, None);
            assert!(ret.is_ok());
            let ret = nc::close(fd);
            assert!(ret.is_ok());
            let ret = nc::unlinkat(nc::AT_FDCWD, path, 0);
            assert!(ret.is_ok());
            nc::exit(0);
        }
    }

    let pid = pid.unwrap();
    println!("[parent] child pid: {}", pid);

    let t = nc::timespec_t {
        tv_sec: 2,
        tv_nsec: 0,
    };
    let ret = unsafe { nc::nanosleep(&t, None) };
    assert!(ret.is_ok());

    let pidfd = unsafe { nc::pidfd_open(pid, 0) };
    assert!(pidfd.is_ok());
    let pidfd = pidfd.unwrap();

    let ret = unsafe { nc::pidfd_getfd(pidfd, STDOUT_FD, 0) };
    println!("ret: {:?}", ret);
    if let Err(errno) = ret {
        eprintln!("pidfd_getfd() failed, err: {}", nc::strerror(errno));
    }
    let child_stdout_fd = ret.unwrap();
    let msg = "Hello, msg from parent process\n";
    let ret = unsafe { nc::write(child_stdout_fd, msg.as_ptr() as usize, msg.len()) };
    assert!(ret.is_ok());
    let nwrite = ret.unwrap();
    assert_eq!(nwrite as usize, msg.len());

    let mut info = nc::siginfo_t::default();
    let ret = unsafe { nc::pidfd_send_signal(pidfd, nc::SIGKILL, &mut info, 0) };
    println!("ret: {:?}", ret);
    if let Err(errno) = ret {
        eprintln!("pidfd_send_signal() failed, err: {}", nc::strerror(errno));
    }

    unsafe {
        let ret = nc::close(pidfd);
        assert!(ret.is_ok());
        let ret = nc::close(child_stdout_fd);
        assert!(ret.is_ok());
    }
}