hush/freeramdisk.c

74 lines
1.8 KiB
C

/* vi: set sw=4 ts=4: */
/*
* freeramdisk implementation for busybox
*
* Copyright (C) 2000 and written by Emanuele Caratti <wiz@iol.it>
* Adjusted a bit by Erik Andersen <andersee@debian.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <errno.h>
#include "internal.h"
/* From linux/fs.h */
#define BLKFLSBUF _IO(0x12,97) /* flush buffer cache */
static const char freeramdisk_usage[] =
"freeramdisk DEVICE\n"
#ifndef BB_FEATURE_TRIVIAL_HELP
"\nFrees all memory used by the specified ramdisk.\n"
#endif
;
extern int
freeramdisk_main(int argc, char **argv)
{
int f;
if (argc != 2 || *argv[1] == '-') {
usage(freeramdisk_usage);
}
if ((f = open(argv[1], O_RDWR)) == -1) {
fatalError( "cannot open %s: %s\n", argv[1], strerror(errno));
}
if (ioctl(f, BLKFLSBUF) < 0) {
fatalError( "failed ioctl on %s: %s\n", argv[1], strerror(errno));
}
/* Don't bother closing. Exit does
* that, so we can save a few bytes */
/* close(f); */
return(TRUE);
}
/*
Local Variables:
c-file-style: "linux"
c-basic-offset: 4
tab-width: 4
End:
*/