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

Last change on this file since 10 was 9, checked in by Mattia Monga, 13 years ago

Minix 3.1.2a

File size: 2.2 KB
Line 
1/* printroot - print root device on stdout Author: Bruce Evans */
2
3/* This program figures out what the root device is by doing a stat on it, and
4 * then searching /dev until it finds an entry with the same device number.
5 * A typical use (probably the only use) is in /etc/rc for initializing
6 * /etc/mtab, as follows:
7 *
8 * /usr/bin/printroot >/etc/mtab
9 *
10 * 9 Dec 1989 - clean up for 1.5 - full prototypes (BDE)
11 * 15 Oct 1989 - avoid ACK cc bugs (BDE):
12 * - sizeof "foo" is 2 (from wrong type char *) instead of 4
13 * - char foo[10] = "bar"; allocates 4 bytes instead of 10
14 * 1 Oct 1989 - Minor changes by Andy Tanenbaum
15 * 5 Oct 1992 - Use readdir (kjb)
16 * 26 Nov 1994 - Flag -r: print just the root device (kjb)
17 */
18
19#include <sys/types.h>
20#include <sys/stat.h>
21#include <fcntl.h>
22#include <limits.h>
23#include <stdlib.h>
24#include <string.h>
25#include <unistd.h>
26#include <minix/minlib.h>
27#include <dirent.h>
28
29static char DEV_PATH[] = "/dev/"; /* #define would step on sizeof bug */
30static char MESSAGE[] = " / "; /* ditto */
31#define UNKNOWN_DEV "/dev/unknown"
32#define ROOT "/"
33int rflag;
34
35_PROTOTYPE(int main, (int argc, char **argv));
36_PROTOTYPE(void done, (char *name, int status));
37
38int main(argc, argv)
39int argc;
40char **argv;
41{
42 DIR *dp;
43 struct dirent *entry;
44 struct stat filestat, rootstat;
45 static char namebuf[sizeof DEV_PATH + NAME_MAX];
46
47 rflag = (argc > 1 && strcmp(argv[1], "-r") == 0);
48
49 if (stat(ROOT, &rootstat) == 0 && (dp = opendir(DEV_PATH)) != (DIR *) NULL) {
50 while ((entry = readdir(dp)) != (struct dirent *) NULL) {
51 strcpy(namebuf, DEV_PATH);
52 strcat(namebuf, entry->d_name);
53 if (stat(namebuf, &filestat) != 0) continue;
54 if ((filestat.st_mode & S_IFMT) != S_IFBLK) continue;
55 if (filestat.st_rdev != rootstat.st_dev) continue;
56 done(namebuf, 0);
57 }
58 }
59 done(UNKNOWN_DEV, 1);
60 return(0); /* not reached */
61}
62
63void done(name, status)
64char *name;
65int status;
66{
67 int v;
68
69 write(1, name, strlen(name));
70 if (rflag) {
71 write(1, "\n", 1);
72 exit(status);
73 }
74 write(1, MESSAGE, sizeof MESSAGE - 1);
75 v = fsversion(name, "printroot"); /* determine file system version */
76 if (v == 1)
77 write(1, "1 rw\n", 5);
78 else if (v == 2)
79 write(1, "2 rw\n", 5);
80 else if (v == 3)
81 write(1, "3 rw\n", 5);
82 else
83 write(1, "0 rw\n", 5);
84 exit(status);
85}
Note: See TracBrowser for help on using the repository browser.