csci4061/notes/09-pipes-fifos-code/fill_pipe.c
Michael Zhang 041f660ccd
f
2018-01-29 17:28:37 -06:00

34 lines
854 B
C

// Demonstrates fillling a pipe which only occasionally gets read from
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#define BUFSIZE 1024
int main(int argc, char *argv[]){
int pip[2];
pipe(pip);
int pid = fork();
if(pid == 0){ // CHILD
char buf[BUFSIZE];
while(1){
sleep(1); // sleep then...
printf("Reading ...\n");
fflush(stdout);
read(pip[0], buf, BUFSIZE); // empty the pipe a bit
}
}
else{ // PARENT
for(int i=1; ; i++){ // keep writing to the pipe
char c = '-';
write(pip[1], &c, 1); // blocks when pipe is full
printf("Wrote %d so far\n",i);
fflush(stdout);
}
}
return 0;
}