58 lines
1.4 KiB
C
58 lines
1.4 KiB
C
|
/*
|
||
|
|
* asynctest.c: use async notification to read stdin
|
||
|
|
*
|
||
|
|
* Copyright (C) 2001 Alessandro Rubini and Jonathan Corbet
|
||
|
|
* Copyright (C) 2001 O'Reilly & Associates
|
||
|
|
*
|
||
|
|
* The source code in this file can be freely used, adapted,
|
||
|
|
* and redistributed in source or binary form, so long as an
|
||
|
|
* acknowledgment appears in derived source files. The citation
|
||
|
|
* should list that the code comes from the book "Linux Device
|
||
|
|
* Drivers" by Alessandro Rubini and Jonathan Corbet, published
|
||
|
|
* by O'Reilly & Associates. No warranty is attached;
|
||
|
|
* we cannot take responsibility for errors or fitness for use.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <stdio.h>
|
||
|
|
#include <stdlib.h>
|
||
|
|
#include <string.h>
|
||
|
|
#include <unistd.h>
|
||
|
|
#include <signal.h>
|
||
|
|
#include <fcntl.h>
|
||
|
|
|
||
|
|
int gotdata=0;
|
||
|
|
void sighandler(int signo)
|
||
|
|
{
|
||
|
|
if (signo==SIGIO)
|
||
|
|
gotdata++;
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
char buffer[4096];
|
||
|
|
|
||
|
|
int main(int argc, char **argv)
|
||
|
|
{
|
||
|
|
int count;
|
||
|
|
struct sigaction action;
|
||
|
|
|
||
|
|
memset(&action, 0, sizeof(action));
|
||
|
|
action.sa_handler = sighandler;
|
||
|
|
action.sa_flags = 0;
|
||
|
|
|
||
|
|
sigaction(SIGIO, &action, NULL);
|
||
|
|
|
||
|
|
fcntl(STDIN_FILENO, F_SETOWN, getpid());
|
||
|
|
fcntl(STDIN_FILENO, F_SETFL, fcntl(STDIN_FILENO, F_GETFL) | FASYNC);
|
||
|
|
|
||
|
|
while(1) {
|
||
|
|
/* this only returns if a signal arrives */
|
||
|
|
sleep(86400); /* one day */
|
||
|
|
if (!gotdata)
|
||
|
|
continue;
|
||
|
|
count=read(0, buffer, 4096);
|
||
|
|
/* buggy: if avail data is more than 4kbytes... */
|
||
|
|
write(1,buffer,count);
|
||
|
|
gotdata=0;
|
||
|
|
}
|
||
|
|
}
|