/*
   bigfile.c - Make a big file that doesn't actually take up any disk space.
   To build on 64-bit Linux: "make bigfile"
   To build on 32-bit Linux: 
   make bigfile "CFLAGS=-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64"
   To build on Solaris:  "make bigfile CFLAGS=-xarch=generic64"
   F. da Cruz, Columbia University, 24 Dec 2005
*/
#include <stdio.h>
#include <sys/types.h>
main() {
    FILE * fp;
    off_t offset;
    offset = 3000000000LL;		/* > 2^31 */
    offset = 4300000000LL;		/* > 2^32 */
    if ((int)(sizeof(off_t)) < 8) {
	printf("sizeof off_t is %d - can't make big files\n",
	       (int)(sizeof(off_t))
	       );
    }
    printf("sizeof off_t: %d\n", (int)(sizeof(off_t)));
    /* Create the file */
    if (!(fp = fopen("BIGFILE","w"))) {
	perror("fopen BIGFILE\n");
	exit(1);
    }
    /* Seek to a spot at the desired offset */
    /* (This gets EINVAL errors on old Linux versions like RH6.1 */
    /* even though off_t is 64 bits). */
    if (fseeko(fp,offset,SEEK_SET) < 0) {
	perror("fseeko");
	exit(1);
    }
    /* Write one byte at the far end */
    if (fputc('x',fp) == EOF) {
	perror("fputc");
	exit(1);
    }
    fclose(fp);
    exit(0);
}