xref: /csrg-svn/lib/libc/gen/ttyname.c (revision 39113)
11994Swnj /*
235450Sbostic  * Copyright (c) 1988 The Regents of the University of California.
335450Sbostic  * All rights reserved.
435450Sbostic  *
535450Sbostic  * Redistribution and use in source and binary forms are permitted
635450Sbostic  * provided that the above copyright notice and this paragraph are
735450Sbostic  * duplicated in all such forms and that any documentation,
835450Sbostic  * advertising materials, and other materials related to such
935450Sbostic  * distribution and use acknowledge that the software was developed
1035450Sbostic  * by the University of California, Berkeley.  The name of the
1135450Sbostic  * University may not be used to endorse or promote products derived
1235450Sbostic  * from this software without specific prior written permission.
1335450Sbostic  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
1435450Sbostic  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
1535450Sbostic  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
161994Swnj  */
171994Swnj 
1835450Sbostic #if defined(LIBC_SCCS) && !defined(lint)
19*39113Sbostic static char sccsid[] = "@(#)ttyname.c	5.4 (Berkeley) 09/11/89";
2035450Sbostic #endif /* LIBC_SCCS and not lint */
2135450Sbostic 
2235450Sbostic #include <sys/types.h>
236715Smckusick #include <sys/dir.h>
241994Swnj #include <sys/stat.h>
2535450Sbostic #include <sgtty.h>
26*39113Sbostic #include <paths.h>
271994Swnj 
281994Swnj char *
2935450Sbostic ttyname(fd)
3035450Sbostic 	int fd;
311994Swnj {
3235450Sbostic 	register struct direct *dirp;
3335450Sbostic 	register DIR *dp;
3435450Sbostic 	struct stat sb1, sb2;
3535450Sbostic 	struct sgttyb ttyb;
36*39113Sbostic 	static char buf[sizeof(_PATH_DEV) + MAXNAMLEN] = _PATH_DEV;
3735450Sbostic 	char *rval, *strcpy();
381994Swnj 
3935450Sbostic 	if (ioctl(fd, TIOCGETP, &ttyb) < 0)
401994Swnj 		return(NULL);
4135450Sbostic 	if (fstat(fd, &sb1) < 0 || (sb1.st_mode&S_IFMT) != S_IFCHR)
421994Swnj 		return(NULL);
43*39113Sbostic 	if ((dp = opendir(_PATH_DEV)) == NULL)
441994Swnj 		return(NULL);
4535450Sbostic 	for (rval = NULL; dirp = readdir(dp);) {
4635450Sbostic 		if (dirp->d_ino != sb1.st_ino)
471994Swnj 			continue;
48*39113Sbostic 		(void)strcpy(buf + sizeof(_PATH_DEV) - 1, dirp->d_name);
4935450Sbostic 		if (stat(buf, &sb2) < 0 || sb1.st_dev != sb2.st_dev ||
5035450Sbostic 		    sb1.st_ino != sb1.st_ino)
511994Swnj 			continue;
5235450Sbostic 		closedir(dp);
5335450Sbostic 		rval = buf;
5435450Sbostic 		break;
551994Swnj 	}
5635450Sbostic 	closedir(dp);
5735450Sbostic 	return(rval);
581994Swnj }
59