release/src/router/busybox/util-linux/freeramdisk.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * freeramdisk and fdflush implementations for busybox
   4  *
   5  * Copyright (C) 2000 and written by Emanuele Caratti <wiz@iol.it>
   6  * Adjusted a bit by Erik Andersen <andersen@codepoet.org>
   7  * Unified with fdflush by Tito Ragusa <farmatito@tiscali.it>
   8  *
   9  * Licensed under GPLv2, see file LICENSE in this source tree.
  10  */
  11
  12 //usage:#define freeramdisk_trivial_usage
  13 //usage:       "DEVICE"
  14 //usage:#define freeramdisk_full_usage "\n\n"
  15 //usage:       "Free all memory used by the specified ramdisk"
  16 //usage:
  17 //usage:#define freeramdisk_example_usage
  18 //usage:       "$ freeramdisk /dev/ram2\n"
  19 //usage:
  20 //usage:#define fdflush_trivial_usage
  21 //usage:       "DEVICE"
  22 //usage:#define fdflush_full_usage "\n\n"
  23 //usage:       "Force floppy disk drive to detect disk change"
  24
  25 #include <sys/mount.h>
  26 #include "libbb.h"
  27
  28 /* From <linux/fd.h> */
  29 #define FDFLUSH  _IO(2,0x4b)
  30
  31 int freeramdisk_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  32 int freeramdisk_main(int argc UNUSED_PARAM, char **argv)
  33 {
  34         int fd;
  35
  36         fd = xopen(single_argv(argv), O_RDWR);
  37
  38         // Act like freeramdisk, fdflush, or both depending on configuration.
  39         ioctl_or_perror_and_die(fd, (ENABLE_FREERAMDISK && applet_name[1] == 'r')
  40                         || !ENABLE_FDFLUSH ? BLKFLSBUF : FDFLUSH, NULL, "%s", argv[1]);
  41
  42         if (ENABLE_FEATURE_CLEAN_UP) close(fd);
  43
  44         return EXIT_SUCCESS;
  45 }