//
// Created by haraldwolff on 21.08.22.
//

#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/mman.h>
#include <getopt.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>

int main(int argc, char *argv[]){
	int ch;
	char filename[1024] = "";

	while ((ch = getopt(argc, argv, "f:"))!=-1){
		switch (ch){
			case 'f':
				strncpy(filename, optarg, 1024);
				break;
		}
	}

	if (!filename[0]){
		printf("need filename:   blockfill -f <filename>\n");
		exit(EXIT_FAILURE);
	}

	int f = open(filename, O_RDWR);
	if (f < 0)
	{
		printf("could not open %s (%s)\n", filename, strerror(errno));
		exit(EXIT_FAILURE);
	}
	long size = lseek(f, 0, SEEK_END);

	void *mm = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, f, 0);
	if (mm == MAP_FAILED){
		printf("could not mmap file.");
	} else {
		long offset = 0;
		u_int64_t *t = (u_int64_t *)mm;

		while (offset < size) {
			for (int n = 0; n < 512; n++) {
				t[ (offset >> 3) + n ] = offset;
			}
			offset += 4096;
			printf("\roffset: 0x%llx  %d%%", offset, (100 * offset / size));
		}
		printf("\n");

		munmap(mm, size);
	}
	close(f);

}