cmd/randfree_file/randfree_file.c

	randfree_file.c revision d583b39bfb4e2571d3e41097c5c357ffe353ad45
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Copyright (c) 2012 by Delphix. All rights reserved.
 */

#include "../file_common.h"

/*
 * Create a file with assigned size and then free the specified
 * section of the file
 */

static void usage(char *progname);

static void
usage(char *progname)
{
    (void) fprintf(stderr,
        "usage: %s [-l filesize] [-s start-offset]"
        "[-n section-len] filename\n", progname);
    exit(1);
}

int
main(int argc, char *argv[])
{
    char *filename = NULL;
    char *buf;
    size_t filesize = 0;
    off_t start_off = 0;
    off_t off_len = 0;
    int  fd, ch;
    struct flock fl;
    mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;

    while ((ch = getopt(argc, argv, "l:s:n:")) != EOF) {
        switch (ch) {
        case 'l':
            filesize = atoll(optarg);
            break;
        case 's':
            start_off = atoll(optarg);
            break;
        case 'n':
            off_len = atoll(optarg);
            break;
        default:
            usage(argv[0]);
            break;
        }
    }

    if (optind == argc - 1)
        filename = argv[optind];
    else
        usage(argv[0]);

    buf = (char *)malloc(filesize);

    if ((fd = open(filename, O_RDWR | O_CREAT | O_TRUNC, mode)) < 0) {
        perror("open");
        return (1);
    }
    if (write(fd, buf, filesize) < filesize) {
        perror("write");
        return (1);
    }
    fl.l_whence = SEEK_SET;
    fl.l_start = start_off;
    fl.l_len = off_len;
    if (fcntl(fd, F_FREESP, &fl) != 0) {
        perror("fcntl");
        return (1);
    }

    free(buf);
    return (0);
}