libevent/sample/event-test.c

/*
 * XXX This sample code was once meant to show how to use the basic Libevent
 * interfaces, but it never worked on non-Unix platforms, and some of the
 * interfaces have changed since it was first written.  It should probably
 * be removed or replaced with something better.
 *
 * Compile with:
 * cc -I/usr/local/include -o event-test event-test.c -L/usr/local/lib -levent
 */

#include <event2/event-config.h>

#include <sys/types.h>
#include <sys/stat.h>
#ifndef WIN32
#include <sys/queue.h>
#include <unistd.h>
#include <sys/time.h>
#else
#include <winsock2.h>
#include <windows.h>
#endif
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>

#include <event.h>

static void
fifo_read(int fd, short event, void *arg)
{
	char buf[255];
	int len;
	struct event *ev = arg;
#ifdef WIN32
	DWORD dwBytesRead;
#endif

	/* Reschedule this event */
	event_add(ev, NULL);

	fprintf(stderr, "fifo_read called with fd: %d, event: %d, arg: %p\n",
		fd, event, arg);
#ifdef WIN32
	len = ReadFile((HANDLE)fd, buf, sizeof(buf) - 1, &dwBytesRead, NULL);

	/* Check for end of file. */
	if (len && dwBytesRead == 0) {
		fprintf(stderr, "End Of File");
		event_del(ev);
		return;
	}

	buf[dwBytesRead] = '\0';
#else
	len = read(fd, buf, sizeof(buf) - 1);

	if (len == -1) {
		perror("read");
		return;
	} else if (len == 0) {
		fprintf(stderr, "Connection closed\n");
		return;
	}

	buf[len] = '\0';
#endif
	fprintf(stdout, "Read: %s\n", buf);
}

int
main(int argc, char **argv)
{
	struct event evfifo;
#ifdef WIN32
	HANDLE socket;
	/* Open a file. */
	socket = CreateFileA("test.txt",	/* open File */
			GENERIC_READ,		/* open for reading */
			0,			/* do not share */
			NULL,			/* no security */
			OPEN_EXISTING,		/* existing file only */
			FILE_ATTRIBUTE_NORMAL,	/* normal file */
			NULL);			/* no attr. template */

	if (socket == INVALID_HANDLE_VALUE)
		return 1;

#else
	struct stat st;
	const char *fifo = "event.fifo";
	int socket;

	if (lstat(fifo, &st) == 0) {
		if ((st.st_mode & S_IFMT) == S_IFREG) {
			errno = EEXIST;
			perror("lstat");
			exit(1);
		}
	}

	unlink(fifo);
	if (mkfifo(fifo, 0600) == -1) {
		perror("mkfifo");
		exit(1);
	}

	/* Linux pipes are broken, we need O_RDWR instead of O_RDONLY */
#ifdef __linux
	socket = open(fifo, O_RDWR | O_NONBLOCK, 0);
#else
	socket = open(fifo, O_RDONLY | O_NONBLOCK, 0);
#endif

	if (socket == -1) {
		perror("open");
		exit(1);
	}

	fprintf(stderr, "Write data to %s\n", fifo);
#endif
	/* Initalize the event library */
	event_init();

	/* Initalize one event */
#ifdef WIN32
	event_set(&evfifo, (int)socket, EV_READ, fifo_read, &evfifo);
#else
	event_set(&evfifo, socket, EV_READ, fifo_read, &evfifo);
#endif

	/* Add it to the active events, without a timeout */
	event_add(&evfifo, NULL);

	event_dispatch();
#ifdef WIN32
	CloseHandle(socket);
#endif
	return (0);
}