pipe-cooler.c

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <time.h>

typedef unsigned char byte_t;

double timestamp_now() {
	struct timespec t_time;
	double m_time;

	if (clock_gettime(CLOCK_MONOTONIC, &t_time) < 0)
		return 0.0;

	m_time = (double)t_time.tv_sec + ((double)t_time.tv_nsec / 1000000000.0);
	return m_time;
}

int main(int argc, char**argv) {
	char buffer[256];
	double cTime = 0.0, lTime = 0.0;
	int limit=1; // defaults to 1 sec
	byte_t raw_mode = 0;
	unsigned int read;

	if (argc>1) { // Argument 1 is interperted as Hz or B/s with -r
		limit=atoi(argv[1]);
	}
	if (argc>2) { // Argument 2 is binary mode
		if (strcmp(argv[2], "-b") == 0) {
			raw_mode = 1;
		}
	}

	setvbuf(stdout,NULL,_IONBF,0);
  
	if (!raw_mode) {
		while ((fgets(buffer, sizeof(buffer), stdin)) != NULL) {
			cTime = timestamp_now();
			if (cTime - lTime >= (1.0 / limit)) {
				fputs(buffer, stdout);
				lTime = cTime;
			}
		}
	}
	else {
		while ((read = fread(buffer, limit, 1, stdin)) > 0) {
			fwrite(buffer, limit, 1, stdout);
			sleep(1);
		}
	}

  return 0;
}