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 * 6 * 9 Dec 1989 - clean up for 1.5 - full prototypes (BDE) 7 * 15 Oct 1989 - avoid ACK cc bugs (BDE): 8 * - sizeof "foo" is 2 (from wrong type char *) instead of 4 9 * - char foo[10] = "bar"; allocates 4 bytes instead of 10 10 * 1 Oct 1989 - Minor changes by Andy Tanenbaum 11 * 5 Oct 1992 - Use readdir (kjb) 12 * 26 Nov 1994 - Flag -r: print just the root device (kjb) 13 */ 14 15 #include <sys/types.h> 16 #include <sys/stat.h> 17 #include <fcntl.h> 18 #include <limits.h> 19 #include <stdlib.h> 20 #include <string.h> 21 #include <unistd.h> 22 #include <minix/minlib.h> 23 #include <dirent.h> 24 25 static char DEV_PATH[] = "/dev/"; /* #define would step on sizeof bug */ 26 static char MESSAGE[] = " / "; /* ditto */ 27 #define UNKNOWN_DEV "/dev/unknown" 28 #define ROOT "/" 29 int rflag; 30 31 int main(int argc, char **argv); 32 void done(char *name, int status); 33 34 int main(argc, argv) 35 int argc; 36 char **argv; 37 { 38 DIR *dp; 39 struct dirent *entry; 40 struct stat filestat, rootstat; 41 static char namebuf[sizeof DEV_PATH + NAME_MAX]; 42 43 rflag = (argc > 1 && strcmp(argv[1], "-r") == 0); 44 45 if (stat(ROOT, &rootstat) == 0 && (dp = opendir(DEV_PATH)) != (DIR *) NULL) { 46 while ((entry = readdir(dp)) != (struct dirent *) NULL) { 47 strcpy(namebuf, DEV_PATH); 48 strcat(namebuf, entry->d_name); 49 if (stat(namebuf, &filestat) != 0) continue; 50 if ((filestat.st_mode & S_IFMT) != S_IFBLK) continue; 51 if (filestat.st_rdev != rootstat.st_dev) continue; 52 done(namebuf, 0); 53 } 54 } 55 done(UNKNOWN_DEV, 1); 56 return(0); /* not reached */ 57 } 58 59 void done(name, status) 60 char *name; 61 int status; 62 { 63 int v; 64 65 write(1, name, strlen(name)); 66 if (rflag) { 67 write(1, "\n", 1); 68 exit(status); 69 } 70 write(1, MESSAGE, sizeof MESSAGE - 1); 71 v = fsversion(name, "printroot"); /* determine file system version */ 72 switch (v) { 73 case FSVERSION_MFS1: write(1, "1 rw\n", 5); break; 74 case FSVERSION_MFS2: write(1, "2 rw\n", 5); break; 75 case FSVERSION_MFS3: write(1, "3 rw\n", 5); break; 76 case FSVERSION_EXT2: write(1, "ext2 rw\n", 8); break; 77 default: write(1, "0 rw\n", 5); break; 78 } 79 exit(status); 80 } 81