source: trunk/minix/commands/simple/umount.c@ 10

/* umount - unmount a file system               Author: Andy Tanenbaum */

#define _MINIX 1                /* for proto of the non-POSIX umount() */
#define _POSIX_SOURCE 1         /* for PATH_MAX from limits.h */

#include <sys/types.h>
#include <sys/svrctl.h>
#include <fcntl.h>
#include <errno.h>
#include <limits.h>
#include <minix/minlib.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <stdio.h>

_PROTOTYPE(int main, (int argc, char **argv));
_PROTOTYPE(void update_mtab, (char *devname));
_PROTOTYPE(void usage, (void));
_PROTOTYPE(void tell, (char *this));

static char mountpoint[PATH_MAX+1];

int main(argc, argv)
int argc;
char *argv[];
{
  int sflag = 0;

  while (argc > 1 && argv[1][0] == '-') {
        char *opt = argv[1]+1;
        while (*opt) if (*opt++ == 's') sflag = 1; else usage();
        argc--;
        argv++;
  }
  if (argc != 2) usage();
  if ((sflag ? svrctl(MMSWAPOFF, NULL) : umount(argv[1])) < 0) {
        if (errno == EINVAL)
                std_err("Device not mounted\n");
        else
                perror("umount");
        exit(1);
  }
  update_mtab(argv[1]);
  tell(argv[1]);
  tell(" unmounted");
  if (*mountpoint != '\0') {
        tell(" from ");
        tell(mountpoint);
  }
  tell("\n");
  return(0);
}

void update_mtab(devname)
char *devname;
{
/* Remove an entry from /etc/mtab. */
  int n;
  char special[PATH_MAX+1], mounted_on[PATH_MAX+1], version[10], rw_flag[10];

  if (load_mtab("umount") < 0) {
        std_err("/etc/mtab not updated.\n");
        exit(1);
  }
  while (1) {
        n = get_mtab_entry(special, mounted_on, version, rw_flag);
        if (n < 0) break;
        if (strcmp(devname, special) == 0) {
                strcpy(mountpoint, mounted_on);
                continue;
        }
        (void) put_mtab_entry(special, mounted_on, version, rw_flag);
  }
  n = rewrite_mtab("umount");
  if (n < 0) {
        std_err("/etc/mtab not updated.\n");
        exit(1);
  }
}

void usage()
{
  std_err("Usage: umount [-s] special\n");
  exit(1);
}

void tell(this)
char *this;
{
  write(1, this, strlen(this));
}