fast_writer | slow_reader

fast_writer.c

#include <stdio.h>
int main(int argc, char** argv) {
    char buf[256];
    for(int i = 0; i < 1000000; i++){
        fprintf(stdout, "line %d\n", i);
        fprintf(stderr, "[wr] line %d writed\n", i);
    }
}

launch.sh

#!/bin/bash
gcc -o slow_reader slow_reader.c
gcc -o fast_writer fast_writer.c

./fast_writer | ./slow_reader

slow_reader.c

#include <stdio.h>
#include <unistd.h>
int main(int argc, char** argv) {
    char *line = NULL;
    size_t size;
    while(getline(&line, &size, stdin) != -1) {
        printf("[rd] %s", line);
        usleep(1000);
    }
}