use err/warn(3); getbsize no longer needs the program name

[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   5.14 (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 <db.h>
#include <string.h>
#include <paths.h>

static char buf[sizeof(_PATH_DEV) + MAXNAMLEN] = _PATH_DEV;
static char *oldttyname __P((int, struct stat *));

char *
ttyname(fd)
       int fd;
{
       struct stat sb;
       struct sgttyb ttyb;
       DB *db;
       DBT data, key;
       struct {
               mode_t type;
               dev_t dev;
       } bkey;

       /* 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 = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL)) {
               bkey.type = S_IFCHR;
               bkey.dev = sb.st_rdev;
               key.data = &bkey;
               key.size = sizeof(bkey);
               if (!(db->get)(db, &key, &data, 0)) {
                       bcopy(data.data,
                           buf + sizeof(_PATH_DEV) - 1, data.size);
                       (void)(db->close)(db);
                       return (buf);
               }
               (void)(db->close)(db);
       }
       return (oldttyname(fd, &sb));
}

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

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

       while (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);
               return (buf);
       }
       (void)closedir(dp);
       return (NULL);
}