1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 /* Copyright (c) 1988 AT&T */
28 /* All Rights Reserved */
29
30 /*
31 * ttyname(f): return "/dev/X" (where X is a relative pathname
32 * under /dev/), which is the name of the tty character special
33 * file associated with the file descriptor f, or NULL if the
34 * pathname cannot be found.
35 *
36 * Ttyname tries to find the tty file by matching major/minor
37 * device, file system ID, and inode numbers of the file
38 * descriptor parameter to those of files in the /dev/ directory.
39 *
40 * It attempts to find a match on major/minor device numbers,
41 * file system ID, and inode numbers, but failing to match on
42 * all three, settles for just a match on device numbers and
43 * file system ID.
44 *
45 * To achieve higher performance and more flexible functionality,
46 * ttyname first looks for the tty file in the directories specified
47 * in the configuration file /etc/ttysrch. Entries in /etc/ttysrch
48 * may be qualified to specify that a partial match may be acceptable.
49 * This further improves performance by allowing an entry which
50 * matches major/minor and file system ID, but not inode number
51 * without searching the entire /dev tree. If /etc/ttysrch does not
52 * exist, ttyname looks in a default list of directories. If after
53 * looking in the most likely places, ttyname still cannot find the
54 * tty file, it recursively searches thru the rest of the /dev/
55 * directory.
56 *
57 * In addition to the public interfaces, ttyname() & ttyname_r(), which
58 * do the lookup based on an open file descriptor,
59 * the private interface _ttyname_dev() does the lookup based on a
60 * major/minor device. It follows the same order of lookup rules and
61 * returns similar information, but matches on just the major/minor
62 * device numbers.
63 */
64
65 #pragma weak _ttyname = ttyname
66
67 #include "lint.h"
68 #include "mtlib.h"
69 #include "libc.h"
70 #include "_libc_gettext.h"
71 #include <sys/sysmacros.h>
72 #include <sys/types.h>
73 #include <dirent.h>
74 #include <fcntl.h>
75 #include <sys/stat.h>
76 #include <stdlib.h>
77 #include <ctype.h>
78 #include <string.h>
79 #include <stdio.h>
80 #include <unistd.h>
81 #include <thread.h>
82 #include <synch.h>
83 #include <errno.h>
84 #include <limits.h>
85 #include <sys/mkdev.h>
86 #include "tsd.h"
87
88 typedef struct entry {
89 char *name;
90 int flags;
91 } entry_t;
92
93 typedef struct special {
94 const char *spcl_name; /* device name */
95 dev_t spcl_rdev; /* matching major/minor devnum */
96 dev_t spcl_fsdev; /* devnum of containing FS */
97 ino_t spcl_inum; /* inum of entry in FS */
98 } spcl_t;
99
100 static int srch_dir(const entry_t path, int match_mask, int depth,
101 const entry_t skip_dirs[], struct stat64 *fsb);
102 static const entry_t *get_pri_dirs(void);
103 static char *ispts(struct stat64 *fsb, int match_mask);
104 static char *ispty(struct stat64 *fsb, int match_mask);
105 static void itoa(int i, char *ptr);
106 static char *_ttyname_common(struct stat64 *fsp, char *buffer,
107 uint_t match_mask);
108
109
110 #define MAX_DEV_PATH TTYNAME_MAX
111 #define MAX_SRCH_DEPTH 4
112
113 #define MATCH_MM 1
114 #define MATCH_FS 2
115 #define MATCH_INO 4
116 #define MATCH_ALL 7
117
118 #define DEV "/dev"
119 #define TTYSRCH "/etc/ttysrch"
120 #define PTS "/dev/pts"
121
122 static const entry_t dev_dir =
123 { "/dev", MATCH_ALL };
124
125 static const entry_t def_srch_dirs[] = { /* default search list */
126 { "/dev/pts", MATCH_ALL },
127 { "/dev/vt", MATCH_ALL },
128 { "/dev/term", MATCH_ALL },
129 { "/dev/zcons", MATCH_ALL },
130 { NULL, 0 }
131 };
132
133 static char *dir_buf; /* directory buffer for ttysrch body */
134 static entry_t *dir_vec; /* directory vector for ttysrch ptrs */
135 static size_t dir_size; /* ttysrch file size */
136 static timestruc_t dir_mtim; /* ttysrch file modification time */
137 static char rbuf[MAX_DEV_PATH]; /* perfect match file name */
138 static char dev_rbuf[MAX_DEV_PATH]; /* partial match file name */
139 static int dev_flag; /* if set, dev + rdev match was found */
140 static spcl_t special_case[] = {
141 "/dev/tty", 0, 0, 0,
142 "/dev/console", 0, 0, 0,
143 "/dev/conslog", 0, 0, 0,
144 "/dev/systty", 0, 0, 0,
145 "/dev/wscons", 0, 0, 0,
146 "/dev/msglog", 0, 0, 0,
147 };
148 #define NUMSPECIAL (sizeof (special_case) / sizeof (spcl_t))
149 static spcl_t ptmspecial = {
150 "/dev/ptmx", 0, 0, 0
151 };
152 static dev_t ptcdev = NODEV;
153 static dev_t ptsldev = NODEV;
154
155 char *
_ttyname_dev(dev_t rdev,char * buffer,size_t buflen)156 _ttyname_dev(dev_t rdev, char *buffer, size_t buflen)
157 {
158 struct stat64 fsb = { 0 };
159
160 fsb.st_rdev = rdev;
161
162 if (buflen < MAX_DEV_PATH) {
163 errno = ERANGE;
164 return (NULL);
165 }
166
167 return (_ttyname_common(&fsb, buffer, MATCH_MM));
168 }
169
170 /*
171 * POSIX.1c Draft-6 version of the function ttyname_r.
172 * It was implemented by Solaris 2.3.
173 */
174 char *
ttyname_r(int f,char * buffer,int buflen)175 ttyname_r(int f, char *buffer, int buflen)
176 {
177 struct stat64 fsb; /* what we are searching for */
178 /*
179 * do we need to search anything at all? (is fildes a char special tty
180 * file?)
181 */
182 if (fstat64(f, &fsb) < 0) {
183 errno = EBADF;
184 return (0);
185 }
186 if ((isatty(f) == 0) ||
187 ((fsb.st_mode & S_IFMT) != S_IFCHR)) {
188 errno = ENOTTY;
189 return (0);
190 }
191
192 if (buflen < MAX_DEV_PATH) {
193 errno = ERANGE;
194 return (0);
195 }
196
197 return (_ttyname_common(&fsb, buffer, MATCH_ALL));
198 }
199
200 static char *
_ttyname_common(struct stat64 * fsp,char * buffer,uint_t match_mask)201 _ttyname_common(struct stat64 *fsp, char *buffer, uint_t match_mask)
202 {
203 struct stat64 tfsb;
204 const entry_t *srch_dirs; /* priority directories */
205 spcl_t *spclp;
206 int i;
207 int found = 0;
208 int dirno = 0;
209 int is_pts = 0;
210 char *retval = NULL;
211 char *pt = NULL;
212
213 /*
214 * We can't use lmutex_lock() here because we call malloc()/free()
215 * and _libc_gettext(). Use the brute-force callout_lock_enter().
216 */
217 callout_lock_enter();
218
219 /*
220 * match special cases
221 */
222
223 for (spclp = special_case, i = 0; i < NUMSPECIAL; spclp++, i++) {
224 if ((spclp->spcl_inum | spclp->spcl_fsdev |
225 spclp->spcl_rdev) == 0) {
226 if (stat64(spclp->spcl_name, &tfsb) != 0)
227 continue;
228 spclp->spcl_rdev = tfsb.st_rdev;
229 spclp->spcl_fsdev = tfsb.st_dev;
230 spclp->spcl_inum = tfsb.st_ino;
231 }
232 if (match_mask == MATCH_MM) {
233 if (spclp->spcl_rdev == fsp->st_rdev) {
234 retval = strcpy(rbuf, spclp->spcl_name);
235 goto out;
236 }
237 } else if (spclp->spcl_fsdev == fsp->st_dev &&
238 spclp->spcl_rdev == fsp->st_rdev &&
239 spclp->spcl_inum == fsp->st_ino) {
240 retval = strcpy(rbuf, spclp->spcl_name);
241 goto out;
242 }
243 }
244 /*
245 * additional special case: ptm clone device
246 * ptm devs have no entries in /dev
247 * if major number matches, just short circuit any further lookup
248 * NOTE: the minor number of /dev/ptmx is the ptm major number
249 */
250 spclp = &ptmspecial;
251 if ((spclp->spcl_inum | spclp->spcl_fsdev | spclp->spcl_rdev) == 0) {
252 if (stat64(spclp->spcl_name, &tfsb) == 0) {
253 spclp->spcl_rdev = tfsb.st_rdev;
254 spclp->spcl_fsdev = tfsb.st_dev;
255 spclp->spcl_inum = tfsb.st_ino;
256 }
257 }
258 if ((spclp->spcl_rdev != 0) &&
259 (minor(spclp->spcl_rdev) == major(fsp->st_rdev)))
260 goto out;
261
262 /*
263 * additional special case: pty dev
264 * one of the known default pairs of /dev/ptyXX or /dev/ttyXX
265 */
266 if ((retval = ispty(fsp, match_mask)) != NULL)
267 goto out;
268
269 /*
270 * search the priority directories
271 */
272
273
274 srch_dirs = get_pri_dirs();
275 dev_flag = 0;
276
277 while ((!found) && (srch_dirs[dirno].name != NULL)) {
278
279 /*
280 * if /dev is one of the priority directories, only
281 * search its top level(set depth = MAX_SEARCH_DEPTH)
282 */
283
284 /*
285 * Is /dev/pts then just do a quick check. We don't have
286 * to stat the entire /dev/pts dir.
287 */
288 if (strcmp(PTS, srch_dirs[dirno].name) == 0) {
289 if ((pt = ispts(fsp, match_mask)) != NULL) {
290 is_pts = 1;
291 found = 1;
292 }
293 } else {
294 found = srch_dir(srch_dirs[dirno], match_mask,
295 ((strcmp(srch_dirs[dirno].name, dev_dir.name)
296 == 0) ? MAX_SRCH_DEPTH : 1), 0, fsp);
297 }
298 dirno++;
299 }
300
301 /*
302 * search the /dev/ directory, skipping priority directories
303 */
304 if (!found)
305 found = srch_dir(dev_dir, match_mask, 0, srch_dirs, fsp);
306
307
308 /*
309 * return
310 */
311
312 if (found) {
313 if (is_pts)
314 retval = pt;
315 else
316 retval = rbuf;
317 } else if (dev_flag)
318 retval = dev_rbuf;
319 else
320 retval = NULL;
321 out: retval = (retval ? strcpy(buffer, retval) : NULL);
322 callout_lock_exit();
323 return (retval);
324 }
325
326 /*
327 * POSIX.1c standard version of the function ttyname_r.
328 * User gets it via static ttyname_r from the header file.
329 */
330 int
__posix_ttyname_r(int fildes,char * name,size_t namesize)331 __posix_ttyname_r(int fildes, char *name, size_t namesize)
332 {
333 int nerrno = 0;
334 int oerrno = errno;
335 int namelen;
336
337 errno = 0;
338
339 if (namesize > INT_MAX)
340 namelen = INT_MAX;
341 else
342 namelen = (int)namesize;
343
344 if (ttyname_r(fildes, name, namelen) == NULL) {
345 if (errno == 0)
346 nerrno = EINVAL;
347 else
348 nerrno = errno;
349 }
350 errno = oerrno;
351 return (nerrno);
352 }
353
354 /*
355 * Checks if the name is under /dev/pts directory
356 */
357 static char *
ispts(struct stat64 * fsb,int match_mask)358 ispts(struct stat64 *fsb, int match_mask)
359 {
360 static char buf[MAX_DEV_PATH];
361 struct stat64 stb;
362
363 (void) strcpy(buf, "/dev/pts/");
364 itoa(minor(fsb->st_rdev), buf+strlen(buf));
365
366 if (stat64(buf, &stb) != 0)
367 return (NULL);
368
369 if (match_mask == MATCH_MM) {
370 if (stb.st_rdev == fsb->st_rdev)
371 return (buf);
372 } else if (stb.st_rdev == fsb->st_rdev && stb.st_dev == fsb->st_dev &&
373 stb.st_ino == fsb->st_ino)
374 return (buf);
375
376 return (NULL);
377 }
378
379 /*
380 * Checks if the dev is a known pty master or slave device
381 */
382 #define MAXDEFAULTPTY 48
383
384 static char *
ispty(struct stat64 * fsb,int match_mask)385 ispty(struct stat64 *fsb, int match_mask)
386 {
387 static char buf[16]; /* big enough for "/dev/XtyXX" */
388 struct stat64 stb;
389 minor_t dmin;
390 char prefix;
391
392 if (ptsldev == NODEV && stat64("/dev/ttyp0", &stb) == 0)
393 ptsldev = stb.st_rdev;
394
395 /*
396 * check for a ptsl dev (/dev/ttyXX)
397 */
398 prefix = 't';
399 if (major(fsb->st_rdev) != major(ptsldev)) {
400 /*
401 * not a ptsl, check for a ptc
402 */
403 if (ptcdev == NODEV && stat64("/dev/ptyp0", &stb) == 0)
404 ptcdev = stb.st_rdev;
405
406 /*
407 * check for a ptc dev (/dev/ptyXX)
408 */
409 prefix = 'p';
410 if (major(fsb->st_rdev) != major(ptcdev))
411 return (NULL);
412 }
413
414 /*
415 * check if minor number is in the known range
416 */
417 dmin = minor(fsb->st_rdev);
418 if (dmin > MAXDEFAULTPTY)
419 return (NULL);
420
421 /*
422 * modify name based on minor number
423 */
424 (void) snprintf(buf, sizeof (buf), "/dev/%cty%c%c",
425 prefix, 'p' + dmin / 16, "0123456789abcdef"[dmin % 16]);
426
427 if (stat64(buf, &stb) != 0)
428 return (NULL);
429
430 if (match_mask == MATCH_MM) {
431 if (stb.st_rdev == fsb->st_rdev)
432 return (buf);
433 } else if (stb.st_rdev == fsb->st_rdev &&
434 stb.st_dev == fsb->st_dev &&
435 stb.st_ino == fsb->st_ino)
436 return (buf);
437
438 return (NULL);
439 }
440
441
442 /*
443 * Converts a number to a string (null terminated).
444 */
445 static void
itoa(int i,char * ptr)446 itoa(int i, char *ptr)
447 {
448 int dig = 0;
449 int tempi;
450
451 tempi = i;
452 do {
453 dig++;
454 tempi /= 10;
455 } while (tempi);
456
457 ptr += dig;
458 *ptr = '\0';
459 while (--dig >= 0) {
460 *(--ptr) = i % 10 + '0';
461 i /= 10;
462 }
463 }
464
465 /*
466 * srch_dir() searches directory path and all directories under it up
467 * to depth directories deep for a file described by a stat structure
468 * fsb. It puts the answer into rbuf. If a match is found on device
469 * number only, the file name is put into dev_rbuf and dev_flag is set.
470 *
471 * srch_dir() returns 1 if a match (on device and inode) is found,
472 * or 0 otherwise.
473 *
474 */
475
476 static int
srch_dir(const entry_t path,int match_mask,int depth,const entry_t skip_dirs[],struct stat64 * fsb)477 srch_dir(const entry_t path, /* current path */
478 int match_mask, /* flags mask */
479 int depth, /* current depth (/dev = 0) */
480 const entry_t skip_dirs[], /* directories not needing searching */
481 struct stat64 *fsb) /* the file being searched for */
482 {
483 DIR *dirp;
484 struct dirent64 *direntp;
485 struct stat64 tsb;
486 char file_name[MAX_DEV_PATH];
487 entry_t file;
488 char *last_comp;
489 int found = 0;
490 int dirno = 0;
491 size_t path_len;
492
493 file.name = file_name;
494 file.flags = path.flags & match_mask;
495 if (file.flags == 0)
496 file.flags = match_mask;
497
498 /*
499 * do we need to search this directory? (always search /dev at depth 0)
500 */
501 if ((skip_dirs != NULL) && (depth != 0))
502 while (skip_dirs[dirno].name != NULL)
503 if (strcmp(skip_dirs[dirno++].name, path.name) == 0)
504 return (0);
505
506 /*
507 * open directory
508 */
509 if ((dirp = opendir(path.name)) == NULL) {
510 return (0);
511 }
512
513 path_len = strlen(path.name);
514 (void) strcpy(file_name, path.name);
515 last_comp = file_name + path_len;
516 *last_comp++ = '/';
517
518 /*
519 * read thru the directory
520 */
521 while ((!found) && ((direntp = readdir64(dirp)) != NULL)) {
522 /*
523 * skip "." and ".." entries, if present
524 */
525 if (direntp->d_name[0] == '.' &&
526 (strcmp(direntp->d_name, ".") == 0 ||
527 strcmp(direntp->d_name, "..") == 0))
528 continue;
529
530 /*
531 * if the file name (path + "/" + d_name + NULL) would be too
532 * long, skip it
533 */
534 if ((path_len + strlen(direntp->d_name) + 2) > MAX_DEV_PATH)
535 continue;
536
537 (void) strcpy(last_comp, direntp->d_name);
538 if (stat64(file_name, &tsb) < 0)
539 continue;
540
541 if (strcmp(file_name, "/dev/vt/active") == 0)
542 continue;
543
544 /*
545 * skip "/dev/syscon" because it may be an invalid link after
546 * single user mode.
547 */
548 if (strcmp(file_name, "/dev/syscon") == 0)
549 continue;
550
551 /*
552 * if a file is a directory and we are not too deep, recurse
553 */
554 if ((tsb.st_mode & S_IFMT) == S_IFDIR)
555 if (depth < MAX_SRCH_DEPTH)
556 found = srch_dir(file, match_mask, depth+1,
557 skip_dirs, fsb);
558 else
559 continue;
560
561 /*
562 * else if it is not a directory, is it a character special
563 * file?
564 */
565 else if ((tsb.st_mode & S_IFMT) == S_IFCHR) {
566 int flag = 0;
567 if (match_mask & MATCH_FS &&
568 tsb.st_dev == fsb->st_dev)
569 flag |= MATCH_FS;
570 if (match_mask & MATCH_MM &&
571 tsb.st_rdev == fsb->st_rdev)
572 flag |= MATCH_MM;
573 if (match_mask & MATCH_INO &&
574 tsb.st_ino == fsb->st_ino)
575 flag |= MATCH_INO;
576
577 if ((flag & file.flags) == file.flags) {
578 (void) strcpy(rbuf, file.name);
579 found = 1;
580 } else if ((flag & (MATCH_MM | MATCH_FS)) ==
581 (MATCH_MM | MATCH_FS)) {
582
583 /*
584 * no (inodes do not match), but save the name
585 * for later
586 */
587 (void) strcpy(dev_rbuf, file.name);
588 dev_flag = 1;
589 }
590 }
591 }
592 (void) closedir(dirp);
593 return (found);
594 }
595
596
597 /*
598 * get_pri_dirs() - returns a pointer to an array of strings, where each string
599 * is a priority directory name. The end of the array is marked by a NULL
600 * pointer. The priority directories' names are obtained from the file
601 * /etc/ttysrch if it exists and is readable, or if not, a default hard-coded
602 * list of directories.
603 *
604 * /etc/ttysrch, if used, is read in as a string of characters into memory and
605 * then parsed into strings of priority directory names, omitting comments and
606 * blank lines.
607 *
608 */
609
610 #define START_STATE 1
611 #define COMMENT_STATE 2
612 #define DIRNAME_STATE 3
613 #define FLAG_STATE 4
614 #define CHECK_STATE 5
615
616 #define COMMENT_CHAR '#'
617 #define EOLN_CHAR '\n'
618
619 static const entry_t *
get_pri_dirs(void)620 get_pri_dirs(void)
621 {
622 int fd, state;
623 size_t sz;
624 ssize_t size;
625 struct stat64 sb;
626 char *buf, *ebuf;
627 entry_t *vec;
628
629 /*
630 * if no /etc/ttysrch, use defaults
631 */
632 if ((fd = open(TTYSRCH, 0)) < 0)
633 return (def_srch_dirs);
634
635 if (fstat64(fd, &sb) < 0) {
636 (void) close(fd);
637 return (def_srch_dirs);
638 }
639
640 sz = (size_t)sb.st_size;
641 if (dir_vec != NULL && sz == dir_size &&
642 sb.st_mtim.tv_sec == dir_mtim.tv_sec &&
643 sb.st_mtim.tv_nsec == dir_mtim.tv_nsec) {
644 /*
645 * size & modification time match
646 * no need to reread TTYSRCH
647 * just return old pointer
648 */
649 (void) close(fd);
650 return (dir_vec);
651 }
652 buf = realloc(dir_buf, sz + 1);
653 if (buf != NULL) {
654 dir_buf = buf;
655 size = read(fd, dir_buf, sz);
656 }
657 (void) close(fd);
658
659 if (buf == NULL || size < 0) {
660 if (dir_vec != NULL) {
661 free(dir_vec);
662 dir_vec = NULL;
663 }
664 return ((entry_t *)def_srch_dirs);
665 }
666 dir_size = sz;
667 dir_mtim = sb.st_mtim;
668
669 /*
670 * ensure newline termination for buffer. Add an extra
671 * entry to dir_vec for null terminator
672 */
673 ebuf = &dir_buf[size];
674 *ebuf++ = '\n';
675 for (sz = 1, buf = dir_buf; buf < ebuf; ++buf)
676 if (*buf == '\n')
677 ++sz;
678
679 sz *= sizeof (*dir_vec);
680 vec = realloc(dir_vec, sz);
681 if (vec == NULL) {
682 if (dir_vec != NULL) {
683 free(dir_vec);
684 dir_vec = NULL;
685 }
686 return (def_srch_dirs);
687 }
688 dir_vec = vec;
689 state = START_STATE;
690 for (buf = dir_buf; buf < ebuf; ++buf) {
691 switch (state) {
692
693 case START_STATE:
694 if (*buf == COMMENT_CHAR) {
695 state = COMMENT_STATE;
696 break;
697 }
698 if (!isspace(*buf)) { /* skip leading white space */
699 state = DIRNAME_STATE;
700 vec->name = buf;
701 vec->flags = 0;
702 }
703 break;
704
705 case COMMENT_STATE:
706 if (*buf == EOLN_CHAR)
707 state = START_STATE;
708 break;
709
710 case DIRNAME_STATE:
711 if (*buf == EOLN_CHAR) {
712 state = CHECK_STATE;
713 *buf = '\0';
714 } else if (isspace(*buf)) {
715 /* skip trailing white space */
716 state = FLAG_STATE;
717 *buf = '\0';
718 }
719 break;
720
721 case FLAG_STATE:
722 switch (*buf) {
723 case 'M':
724 vec->flags |= MATCH_MM;
725 break;
726 case 'F':
727 vec->flags |= MATCH_FS;
728 break;
729 case 'I':
730 vec->flags |= MATCH_INO;
731 break;
732 case EOLN_CHAR:
733 state = CHECK_STATE;
734 break;
735 }
736 break;
737
738 case CHECK_STATE:
739 if (strncmp(vec->name, DEV, strlen(DEV)) != 0) {
740 int tfd = open("/dev/console", O_WRONLY);
741 if (tfd >= 0) {
742 char buf[256];
743 (void) snprintf(buf, sizeof (buf),
744 _libc_gettext(
745 "ERROR: Entry '%s' in /etc/ttysrch ignored.\n"), vec->name);
746 (void) write(tfd, buf, strlen(buf));
747 (void) close(tfd);
748 }
749 } else {
750 char *slash;
751 slash = vec->name + strlen(vec->name) - 1;
752 while (*slash == '/')
753 *slash-- = '\0';
754 if (vec->flags == 0)
755 vec->flags = MATCH_ALL;
756 vec++;
757 }
758 state = START_STATE;
759 /*
760 * This state does not consume a character, so
761 * reposition the pointer.
762 */
763 buf--;
764 break;
765
766 }
767 }
768 vec->name = NULL;
769 return (dir_vec);
770 }
771
772
773 char *
ttyname(int f)774 ttyname(int f)
775 {
776 char *ans = tsdalloc(_T_TTYNAME, MAX_DEV_PATH, NULL);
777
778 if (ans == NULL)
779 return (NULL);
780 return (ttyname_r(f, ans, MAX_DEV_PATH));
781 }
782