Created
March 21, 2020 09:41
-
-
Save hechen0/1bbc107793ec6cc3b00cbe7d3a54dd29 to your computer and use it in GitHub Desktop.
poll example
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
#include <stdio.h> | |
#include <unistd.h> | |
#include <poll.h> | |
#define TIMEOUT 5 /* poll timeout, in seconds */ | |
int main (void) { | |
struct pollfd fds[2]; | |
int ret; | |
/* watch stdin for input */ | |
fds[0].fd = STDIN_FILENO; | |
fds[0].events = POLLIN; | |
/* watch stdout for ability to write (almost always true) */ | |
fds[1].fd = STDOUT_FILENO; | |
fds[1].events = POLLOUT; | |
/* All set, block! */ | |
ret = poll (fds, 2, TIMEOUT * 1000); | |
if (ret == −1) { | |
perror ("poll"); | |
return 1; | |
} | |
if (!ret) { | |
printf ("%d seconds elapsed.\n", TIMEOUT); | |
return 0; | |
} | |
if (fds[0].revents & POLLIN) | |
printf ("stdin is readable\n"); | |
if (fds[1].revents & POLLOUT) | |
printf ("stdout is writable\n"); | |
return 0; | |
} | |
/* | |
$ ./poll | |
stdout is writable | |
$ ./poll < some_file | |
stdin is readable | |
stdout is writable | |
*/ |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment