poll_client.c

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/*
  FUSE fselclient: FUSE select example client
  Copyright (C) 2008       SUSE Linux Products GmbH
  Copyright (C) 2008       Tejun Heo <teheo@suse.de>
 
  This program can be distributed under the terms of the GNU GPLv2.
  See the file COPYING.
*/
 
#include <sys/select.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
 
#define FSEL_FILES      16
 
int main(void)
{
        static const char hex_map[FSEL_FILES] = "0123456789ABCDEF";
        int fds[FSEL_FILES];
        int i, nfds, tries;
 
        for (i = 0; i < FSEL_FILES; i++) {
                char name[] = { hex_map[i], '\0' };
                fds[i] = open(name, O_RDONLY);
                if (fds[i] < 0) {
                        perror("open");
                        return 1;
                }
        }
        nfds = fds[FSEL_FILES - 1] + 1;
 
        for(tries=0; tries < 16; tries++) {
                static char buf[4096];
                fd_set rfds;
                int rc;
 
                FD_ZERO(&rfds);
                for (i = 0; i < FSEL_FILES; i++)
                        FD_SET(fds[i], &rfds);
 
                rc = select(nfds, &rfds, NULL, NULL, NULL);
 
                if (rc < 0) {
                        perror("select");
                        return 1;
                }
 
                for (i = 0; i < FSEL_FILES; i++) {
                        if (!FD_ISSET(fds[i], &rfds)) {
                                printf("_:   ");
                                continue;
                        }
                        printf("%X:", i);
                        rc = read(fds[i], buf, sizeof(buf));
                        if (rc < 0) {
                                perror("read");
                                return 1;
                        }
                        printf("%02d ", rc);
                }
                printf("\n");
        }
        return 0;
}