usr/src/lib/libbc/libc/sys/4.2/truncate.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #pragma ident   "%Z%%M% %I%     %E% SMI"
  28
  29 #include "chkpath.h"
  30 #include <sys/syscall.h>
  31 #include <unistd.h>
  32 #include <errno.h>
  33 #include <sys/fcntl.h>
  34 #include <sys/param.h>
  35
  36 int
  37 truncate(char *path, off_t length)
  38 {
  39         int fd, ret = 0;
  40
  41         CHKNULL(path);
  42
  43         if (strcmp(path, "/etc/mtab") == 0 || strcmp(path, "/etc/fstab") == 0) {
  44                 errno = ENOENT;
  45                 return (-1);
  46         }
  47         if ((fd = open(path, O_WRONLY)) == -1) {
  48                 return (-1);
  49         }
  50
  51         if (ftruncate(fd, length) == -1) {
  52                 close(fd);
  53                 return (-1);
  54         }
  55         close(fd);
  56         return (0);
  57 }