deallocvt.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * disalloc.c - aeb - 940501 - Disallocate virtual terminal(s)
   4  * Renamed deallocvt.
   5  */
   6 #include "internal.h"
   7 #include <stdlib.h>
   8 #include <stdio.h>
   9 #include <fcntl.h>
  10 #include <sys/types.h>
  11 #include <sys/ioctl.h>
  12
  13 /* From <linux/vt.h> */
  14 #define VT_DISALLOCATE  0x5608  /* free memory associated to vt */
  15
  16 const char deallocvt_usage[] =
  17         "deallocvt N\n"
  18 #ifndef BB_FEATURE_TRIVIAL_HELP
  19          "\nDeallocate unused virtual terminal /dev/ttyN\n"
  20 #endif
  21          ;
  22
  23 int deallocvt_main(int argc, char *argv[])
  24 {
  25         int fd, num, i;
  26
  27         if ((argc != 2) || (**(argv + 1) == '-'))
  28                 usage(deallocvt_usage);
  29
  30         fd = get_console_fd("/dev/console");
  31
  32         if (argc == 1) {
  33                 /* deallocate all unused consoles */
  34                 if (ioctl(fd, VT_DISALLOCATE, 0)) {
  35                         perror("VT_DISALLOCATE");
  36                         exit( FALSE);
  37                 }
  38         } else
  39                 for (i = 1; i < argc; i++) {
  40                         num = atoi(argv[i]);
  41                         if (num == 0)
  42                                 errorMsg("0: illegal VT number\n");
  43                         else if (num == 1)
  44                                 errorMsg("VT 1 cannot be deallocated\n");
  45                         else if (ioctl(fd, VT_DISALLOCATE, num)) {
  46                                 perror("VT_DISALLOCATE");
  47                                 errorMsg("could not deallocate console %d\n", num);
  48                                 exit( FALSE);
  49                         }
  50                 }
  51         return( TRUE);
  52 }