Some corrections, some additions, some embellishments.
[oweals/busybox.git] / 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 "busybox.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 int deallocvt_main(int argc, char *argv[])
17 {
18         int fd, num, i;
19
20         //if ((argc > 2) || ((argv == 2) && (**(argv + 1) == '-')))
21         if (argc > 2)
22                 usage(deallocvt_usage);
23
24         fd = get_console_fd("/dev/console");
25
26         if (argc == 1) {
27                 /* deallocate all unused consoles */
28                 if (ioctl(fd, VT_DISALLOCATE, 0)) {
29                         perror("VT_DISALLOCATE");
30                         return EXIT_FAILURE;
31                 }
32         } else {
33                 for (i = 1; i < argc; i++) {
34                         num = atoi(argv[i]);
35                         if (num == 0)
36                                 error_msg("0: illegal VT number\n");
37                         else if (num == 1)
38                                 error_msg("VT 1 cannot be deallocated\n");
39                         else if (ioctl(fd, VT_DISALLOCATE, num)) {
40                                 perror("VT_DISALLOCATE");
41                                 error_msg_and_die("could not deallocate console %d\n", num);
42                         }
43                 }
44         }
45
46         return EXIT_SUCCESS;
47 }