#define _GNU_SOURCE
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#define FALLOC_FL_PUNCH_HOLE		0x02
#define FALLOC_FL_KEEP_SIZE		0X01
int main(int argc, char **argv)
{
	int fd;
	int mode = 0; 
	int ret = 0;
        if (argc < 2) {
                _exit(1);
        }
	mode = (mode | FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE);  
	if ((fd = open(argv[1], O_RDWR)) < 0) {
              fprintf(stderr, "Cannot open file %s\n", argv[1]);
		_exit(1);
        }
	ret= fallocate(fd,mode,4096,4096);
	if( ret != 0)
		perror("Fallocate fail\n");
	printf("ret = %d\n",ret);
	close(fd);
	return 0;
}