projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 164a2d2d | 1 | /* @(#)ttyname.c 4.2 (Berkeley) %G% */ |
| b11ade1b BJ |
2 | /* |
| 3 | * ttyname(f): return "/dev/ttyXX" which the the name of the | |
| 4 | * tty belonging to file f. | |
| 5 | * NULL if it is not a tty | |
| 6 | */ | |
| 7 | ||
| 8 | #define NULL 0 | |
| 164a2d2d KM |
9 | #include <sys/param.h> |
| 10 | #include <sys/ndir.h> | |
| b11ade1b BJ |
11 | #include <sys/stat.h> |
| 12 | ||
| 13 | static char dev[] = "/dev/"; | |
| 14 | char *strcpy(); | |
| 15 | char *strcat(); | |
| 16 | ||
| 17 | char * | |
| 18 | ttyname(f) | |
| 19 | { | |
| 20 | struct stat fsb; | |
| 21 | struct stat tsb; | |
| 164a2d2d KM |
22 | register struct direct *db; |
| 23 | register DIR *df; | |
| b11ade1b | 24 | static char rbuf[32]; |
| b11ade1b BJ |
25 | |
| 26 | if (isatty(f)==0) | |
| 27 | return(NULL); | |
| 28 | if (fstat(f, &fsb) < 0) | |
| 29 | return(NULL); | |
| 30 | if ((fsb.st_mode&S_IFMT) != S_IFCHR) | |
| 31 | return(NULL); | |
| 164a2d2d | 32 | if ((df = opendir(dev)) == NULL) |
| b11ade1b | 33 | return(NULL); |
| 164a2d2d KM |
34 | while ((db = readdir(df)) != NULL) { |
| 35 | if (db->d_ino != fsb.st_ino) | |
| b11ade1b BJ |
36 | continue; |
| 37 | strcpy(rbuf, dev); | |
| 164a2d2d | 38 | strcat(rbuf, db->d_name); |
| b11ade1b BJ |
39 | if (stat(rbuf, &tsb) < 0) |
| 40 | continue; | |
| 164a2d2d KM |
41 | if (tsb.st_dev == fsb.st_dev && tsb.st_ino == fsb.st_ino) { |
| 42 | closedir(df); | |
| b11ade1b BJ |
43 | return(rbuf); |
| 44 | } | |
| 45 | } | |
| 164a2d2d | 46 | closedir(df); |
| b11ade1b BJ |
47 | return(NULL); |
| 48 | } |