#include<stdio.h>
int main(void)
{
char *file = "hoge.dat";
FILE *fp;
fp = fopen(file, "w");
if (fp == NULL) {
printf("open error %s", file);
} else {
setbuf(fp, NULL);
int i = 0;
for (i = 0; i < 0x7FFFFFFF; i++) {
fprintf(fp, "%d\n", i);
}
}
fclose(fp);
}