This program tests the poll.c example file systsem.
Compile with:
gcc -Wall poll_client.c -o poll_client
Source code
#include <config.h>
#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;
}
Definition in file poll_client.c.