evio.c
A framework for building event based networking applications.
This is a C version of the original evio.
Install
Clone this respository and then use pkg.sh to import dependencies.
$ git clone https://github.com/tidwall/evio.c
$ cd evio.c/
$ pkg.sh import
Example
Here's a simple echo server. Save the following file to echo.c
#include <stdlib.h>
#include <stdio.h>
#include <assert.h>
#include "evio.h"
void serving(int64_t nano, const char **addrs, int naddrs, void *udata) {
for (int i = 0; i < naddrs; i++) {
printf("Serving at %s\n", addrs[i]);
}
}
void error(int64_t nano, const char *msg, bool fatal, void *udata) {
fprintf(stderr, "%s\n", msg);
}
int64_t tick(int64_t nano, void *udata) {
printf("Tick\n");
// next tick in 1 second. This can be any duration in nanoseconds.
return 1e9;
}
void opened(int64_t nano, struct evio_conn *conn, void *udata) {
printf("Connection opened: %s\n", evio_conn_addr(conn));
}
void closed(int64_t nano, struct evio_conn *conn, void *udata) {
printf("Connection closed: %s\n", evio_conn_addr(conn));
}
void data(int64_t nano, struct evio_conn *conn, const void *data, size_t len, void *udata) {
// echo back to the connection
evio_conn_write(conn, data, len);
}
int main() {
struct evio_events evs = {
.serving = serving,
.error = error,
.tick = tick,
.opened = opened,
.closed = closed,
.data = data,
};
// Any number of addresses can be bound to the appliation.
// Here we are listening on tcp port 9999 (ipv4 and ipv6), and at a local
// unix socket file named "socket".
// For ipv4 only use an ip address like tcp://127.0.0.1:9999
// For ipv6 use something like tcp://[::1]:9999
const char *addrs[] = {
"tcp://localhost:9999",
"unix://socket",
};
// Run the application. This is a forever operation.
evio_main(addrs, 2, evs, NULL);
}Then build and run the server
$ cc *.c && ./a.out
And connect
$ nc localhost 9999