2.9BSD - /usr/src/lib/c/gen/ttyname.c

   1: /*	@(#)ttyname.c	2.1	SCCS id keyword	*/
   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
   9: #include <sys/types.h>
  10: #include <sys/dir.h>
  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;
  22:     struct direct db;
  23:     static char rbuf[32];
  24:     register df;
  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);
  32:     if ((df = open(dev, 0)) < 0)
  33:         return(NULL);
  34:     while (read(df, (char *)&db, sizeof(db)) == sizeof(db)) {
  35:         if (db.d_ino == 0)
  36:             continue;
  37:         if (db.d_ino != fsb.st_ino)
  38:             continue;
  39:         strcpy(rbuf, dev);
  40:         strcat(rbuf, db.d_name);
  41:         if (stat(rbuf, &tsb) < 0)
  42:             continue;
  43:         if (tsb.st_dev==fsb.st_dev && tsb.st_ino==fsb.st_ino) {
  44:             close(df);
  45:             return(rbuf);
  46:         }
  47:     }
  48:     close(df);
  49:     return(NULL);
  50: }

Defined functions

Defined variables

Defined macros