Commit | Line | Data |
---|---|---|
87dccba9 | 1 | /* @(#)getcwd.c 4.2 (Berkeley) %G% */ |
9b6e6036 SL |
2 | |
3 | /* | |
4 | * Getwd | |
5 | */ | |
87dccba9 SL |
6 | #include <sys/param.h> |
7 | #include <sys/stat.h> | |
8 | #include <sys/dir.h> | |
9b6e6036 SL |
9 | |
10 | #define dot "." | |
11 | #define dotdot ".." | |
12 | ||
87dccba9 | 13 | static char *name; |
9b6e6036 | 14 | |
87dccba9 SL |
15 | static DIR *file; |
16 | static int off; | |
17 | static struct stat d, dd; | |
18 | static struct direct *dir; | |
9b6e6036 SL |
19 | |
20 | char * | |
21 | getwd(np) | |
87dccba9 | 22 | char *np; |
9b6e6036 | 23 | { |
87dccba9 SL |
24 | dev_t rdev; |
25 | ino_t rino; | |
9b6e6036 | 26 | |
87dccba9 | 27 | off = -1; |
9b6e6036 SL |
28 | *np++ = '/'; |
29 | name = np; | |
30 | stat("/", &d); | |
31 | rdev = d.st_dev; | |
32 | rino = d.st_ino; | |
33 | for (;;) { | |
34 | stat(dot, &d); | |
35 | if (d.st_ino==rino && d.st_dev==rdev) | |
36 | goto done; | |
37 | if ((file = opendir(dotdot)) == NULL) | |
38 | prexit("getwd: cannot open ..\n"); | |
39 | fstat(file->dd_fd, &dd); | |
40 | chdir(dotdot); | |
41 | if(d.st_dev == dd.st_dev) { | |
42 | if(d.st_ino == dd.st_ino) | |
43 | goto done; | |
44 | do | |
45 | if ((dir = readdir(file)) == NULL) | |
46 | prexit("getwd: read error in ..\n"); | |
47 | while (dir->d_ino != d.st_ino); | |
48 | } | |
49 | else do { | |
50 | if ((dir = readdir(file)) == NULL) | |
51 | prexit("getwd: read error in ..\n"); | |
52 | stat(dir->d_name, &dd); | |
53 | } while(dd.st_ino != d.st_ino || dd.st_dev != d.st_dev); | |
54 | closedir(file); | |
55 | cat(); | |
56 | } | |
57 | done: | |
58 | name--; | |
59 | if (chdir(name) < 0) | |
60 | prexit("getwd: can't change back\n"); | |
61 | return (name); | |
62 | } | |
63 | ||
64 | cat() | |
65 | { | |
66 | register i, j; | |
67 | ||
68 | i = -1; | |
69 | while (dir->d_name[++i] != 0); | |
70 | if ((off+i+2) > 1024-1) | |
71 | return; | |
72 | for(j=off+1; j>=0; --j) | |
73 | name[j+i+1] = name[j]; | |
74 | if (off >= 0) | |
75 | name[i] = '/'; | |
76 | off=i+off+1; | |
77 | name[off] = 0; | |
78 | for(--i; i>=0; --i) | |
79 | name[i] = dir->d_name[i]; | |
80 | } | |
81 | ||
82 | prexit(cp) | |
83 | char *cp; | |
84 | { | |
85 | write(2, cp, strlen(cp)); | |
86 | exit(1); | |
87 | } |