cs350/user/testbin/bigfile/bigfile.c

/*
 * Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009
 *	The President and Fellows of Harvard College.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Create a large file in small increments.
 *
 * Should work on emufs (emu0:) once the basic system calls are done,
 * and should work on SFS when the file system assignment is
 * done. Sufficiently small files should work on SFS even before that
 * assignment.
 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <err.h>

static char buffer[100];

int
main(int argc, char *argv[])
{
	const char *filename;
	int i, size;
	int fileid;
	int len;

	if (argc != 3) {
		errx(1, "Usage: bigfile <filename> <size>");
	}

	filename = argv[1];
	size = atoi(argv[2]);

	printf("Creating a file of size %d\n", size);

	fileid = open(filename, O_WRONLY|O_CREAT|O_TRUNC);
	if (fileid < 0) {
		err(1, "%s: create", filename);
	}

	i=0;
	while (i<size) {
		snprintf(buffer, sizeof(buffer), "%-10d", i);
		len = write(fileid, buffer, strlen(buffer));
		if (len<0) {
			err(1, "%s: write", filename);
		}
		i += len;
	}	

	close(fileid);

	return 0;
}