163 lines
3.3 KiB
C
163 lines
3.3 KiB
C
/*
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* This sample code shows how to use Libevent to read from a named pipe.
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* XXX This code could make better use of the Libevent interfaces.
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*
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* XXX This does not work on Windows; ignore everything inside the _WIN32 block.
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*
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* On UNIX, compile with:
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* cc -I/usr/local/include -o event-read-fifo event-read-fifo.c \
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* -L/usr/local/lib -levent
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*/
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#include <event2/event-config.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#ifndef _WIN32
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#include <sys/queue.h>
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#include <unistd.h>
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#include <sys/time.h>
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#include <signal.h>
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#else
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#include <winsock2.h>
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#include <windows.h>
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#endif
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#include <fcntl.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <string.h>
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#include <errno.h>
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#include <event2/event.h>
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static void
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fifo_read(evutil_socket_t fd, short event, void *arg)
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{
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char buf[255];
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int len;
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struct event *ev = arg;
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#ifdef _WIN32
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DWORD dwBytesRead;
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#endif
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fprintf(stderr, "fifo_read called with fd: %d, event: %d, arg: %p\n",
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(int)fd, event, arg);
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#ifdef _WIN32
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len = ReadFile((HANDLE)fd, buf, sizeof(buf) - 1, &dwBytesRead, NULL);
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/* Check for end of file. */
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if (len && dwBytesRead == 0) {
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fprintf(stderr, "End Of File");
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event_del(ev);
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return;
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}
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buf[dwBytesRead] = '\0';
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#else
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len = read(fd, buf, sizeof(buf) - 1);
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if (len <= 0) {
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if (len == -1)
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perror("read");
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else if (len == 0)
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fprintf(stderr, "Connection closed\n");
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event_del(ev);
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event_base_loopbreak(event_get_base(ev));
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return;
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}
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buf[len] = '\0';
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#endif
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fprintf(stdout, "Read: %s\n", buf);
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}
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/* On Unix, cleanup event.fifo if SIGINT is received. */
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#ifndef _WIN32
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static void
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signal_cb(evutil_socket_t fd, short event, void *arg)
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{
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struct event_base *base = arg;
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event_base_loopbreak(base);
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}
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#endif
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int
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main(int argc, char **argv)
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{
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struct event *evfifo;
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struct event_base* base;
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#ifdef _WIN32
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HANDLE socket;
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/* Open a file. */
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socket = CreateFileA("test.txt", /* open File */
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GENERIC_READ, /* open for reading */
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0, /* do not share */
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NULL, /* no security */
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OPEN_EXISTING, /* existing file only */
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FILE_ATTRIBUTE_NORMAL, /* normal file */
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NULL); /* no attr. template */
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if (socket == INVALID_HANDLE_VALUE)
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return 1;
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#else
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struct event *signal_int;
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struct stat st;
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const char *fifo = "event.fifo";
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int socket;
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if (lstat(fifo, &st) == 0) {
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if ((st.st_mode & S_IFMT) == S_IFREG) {
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errno = EEXIST;
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perror("lstat");
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exit(1);
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}
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}
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unlink(fifo);
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if (mkfifo(fifo, 0600) == -1) {
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perror("mkfifo");
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exit(1);
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}
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socket = open(fifo, O_RDONLY | O_NONBLOCK, 0);
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if (socket == -1) {
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perror("open");
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exit(1);
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}
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fprintf(stderr, "Write data to %s\n", fifo);
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#endif
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/* Initialize the event library */
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base = event_base_new();
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/* Initialize one event */
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#ifdef _WIN32
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evfifo = event_new(base, (evutil_socket_t)socket, EV_READ|EV_PERSIST, fifo_read,
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event_self_cbarg());
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#else
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/* catch SIGINT so that event.fifo can be cleaned up */
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signal_int = evsignal_new(base, SIGINT, signal_cb, base);
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event_add(signal_int, NULL);
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evfifo = event_new(base, socket, EV_READ|EV_PERSIST, fifo_read,
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event_self_cbarg());
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#endif
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/* Add it to the active events, without a timeout */
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event_add(evfifo, NULL);
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event_base_dispatch(base);
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event_base_free(base);
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#ifdef _WIN32
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CloseHandle(socket);
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#else
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close(socket);
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unlink(fifo);
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#endif
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libevent_global_shutdown();
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return (0);
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}
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