//io.c

// a single header file is required

#include <ev.h>

#include <stdio.h> // for puts

// every watcher type has its own typedef'd struct

// with the name ev_TYPE

ev_io stdin_watcher;

ev_timer timeout_watcher;

// all watcher callbacks have a similar signature

// this callback is called when data is readable on stdin

static void stdin_cb (EV_P_ ev_io *w, int revents) {

    puts ("stdin ready");

    // for one-shot events, one must manually stop the watcher

    // with its corresponding stop function.

    ev_io_stop (EV_A_ w);

    // this causes all nested ev_run's to stop iterating

    ev_break (EV_A_ EVBREAK_ALL);

}

// another callback, this time for a time-out

static void timeout_cb (EV_P_ ev_timer *w, int revents) {

    puts ("timeout");

    // this causes the innermost ev_run to stop iterating

    ev_break (EV_A_ EVBREAK_ONE);

} 

int main (void) {

    // use the default event loop unless you have special needs

    struct ev_loop *loop = EV_DEFAULT;

    // initialise an io watcher, then start it

    // this one will watch for stdin to become readable

    ev_io_init (&stdin_watcher, stdin_cb,

            /* STDIN_FILENO*/ , EV_READ);

    ev_io_start (loop, &stdin_watcher);

    // initialise a timer watcher, then start it

    // simple non-repeating 5.5 second timeout

    ev_timer_init (&timeout_watcher, timeout_cb, 5.5, .);

    ev_timer_start (loop, &timeout_watcher);

    // now wait for events to arrive

    ev_run (loop, );

    // break was called, so exit

    return ;

}

gcc -c -o io.o io.c

gcc -o io io.o -lev

$ ./io

$ timeout

$ ./io

$

$ stdin ready