typo

[unix-history] / usr / src / lib / libc / gen / ttyname.c

/*
* Copyright (c) 1988 The Regents of the University of California.
* All rights reserved.
*
* %sccs.include.redist.c%
*/

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)ttyname.c   5.8 (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <dirent.h>
#include <sgtty.h>
#include <ndbm.h>
#include <unistd.h>
#include <paths.h>

static char buf[sizeof(_PATH_DEV) + MAXNAMLEN] = _PATH_DEV;

char *
ttyname(fd)
       int fd;
{
       struct stat sb;
       struct sgttyb ttyb;
       DBM *db;
       datum dp, key;
       static char *__oldttyname();

       /* Must be a terminal. */
       if (ioctl(fd, TIOCGETP, &ttyb) < 0)
               return(NULL);
       /* Must be a character device. */
       if (fstat(fd, &sb) || !S_ISCHR(sb.st_mode))
               return(NULL);

       if (!(db = dbm_open(_PATH_DEVDB, O_RDONLY, 0)))
               return(__oldttyname(fd, &sb));
       key.dptr = (char *)&sb.st_rdev;
       key.dsize = sizeof(sb.st_rdev);
       dp = dbm_fetch(db, key);
       if (!dp.dptr)
               return(__oldttyname(fd, &sb));
       bcopy(dp.dptr, buf + sizeof(_PATH_DEV) - 1, dp.dsize);
       return(buf);
}

static char *
__oldttyname(fd, sb)
       int fd;
       struct stat *sb;
{
       register struct dirent *dirp;
       register DIR *dp;
       struct stat dsb;
       char *rval, *strcpy();

       if ((dp = opendir(_PATH_DEV)) == NULL)
               return(NULL);

       for (rval = NULL; dirp = readdir(dp);) {
               if (dirp->d_fileno != sb->st_ino)
                       continue;
               bcopy(dirp->d_name, buf + sizeof(_PATH_DEV) - 1,
                   dirp->d_namlen + 1);
               if (stat(buf, &dsb) || sb->st_dev != dsb.st_dev ||
                   sb->st_ino != dsb.st_ino)
                       continue;
               (void)closedir(dp);
               rval = buf;
               break;
       }
       (void)closedir(dp);
       return(rval);
}