1 /* Copyright (C) 1991-1993,1996-2002,2006,2009,2010
2 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
23 #include <sys/types.h>
31 #include <kernel-features.h>
34 /* Is this used anywhere? It is not exported. */
38 static char *getttyname (const char *dev
, dev_t mydev
,
39 ino64_t myino
, int save
, int *dostat
)
43 libc_freeres_ptr (static char *getttyname_name
);
46 internal_function attribute_compat_text_section
47 getttyname (const char *dev
, dev_t mydev
, ino64_t myino
, int save
, int *dostat
)
49 static size_t namelen
;
53 size_t devlen
= strlen (dev
) + 1;
55 dirstream
= __opendir (dev
);
56 if (dirstream
== NULL
)
62 /* Prepare for the loop. If we already have a buffer copy the directory
63 name we look at into it. */
65 *((char *) __mempcpy (getttyname_name
, dev
, devlen
- 1)) = '/';
67 while ((d
= __readdir64 (dirstream
)) != NULL
)
68 if ((d
->d_fileno
== myino
|| *dostat
)
69 && strcmp (d
->d_name
, "stdin")
70 && strcmp (d
->d_name
, "stdout")
71 && strcmp (d
->d_name
, "stderr"))
73 size_t dlen
= _D_ALLOC_NAMLEN (d
);
74 if (devlen
+ dlen
> namelen
)
76 free (getttyname_name
);
77 namelen
= 2 * (devlen
+ dlen
); /* Big enough. */
78 getttyname_name
= malloc (namelen
);
79 if (! getttyname_name
)
82 /* Perhaps it helps to free the directory stream buffer. */
83 (void) __closedir (dirstream
);
86 *((char *) __mempcpy (getttyname_name
, dev
, devlen
- 1)) = '/';
88 memcpy (&getttyname_name
[devlen
], d
->d_name
, dlen
);
89 if (__xstat64 (_STAT_VER
, getttyname_name
, &st
) == 0
90 #ifdef _STATBUF_ST_RDEV
91 && S_ISCHR (st
.st_mode
) && st
.st_rdev
== mydev
93 && d
->d_fileno
== myino
&& st
.st_dev
== mydev
97 (void) __closedir (dirstream
);
99 __ttyname
= getttyname_name
;
102 return getttyname_name
;
106 (void) __closedir (dirstream
);
112 /* Static buffer in `ttyname'. */
113 libc_freeres_ptr (static char *ttyname_buf
);
116 /* Return the pathname of the terminal FD is open on, or NULL on errors.
117 The returned storage is good only until the next call to this function. */
121 static size_t buflen
;
123 struct stat64 st
, st1
;
129 /* isatty check, tcgetattr is used because it sets the correct
130 errno (EBADF resp. ENOTTY) on error. */
131 if (__builtin_expect (__tcgetattr (fd
, &term
) < 0, 0))
134 if (__fxstat64 (_STAT_VER
, fd
, &st
) < 0)
137 /* We try using the /proc filesystem. */
138 *_fitoa_word (fd
, __stpcpy (procname
, "/proc/self/fd/"), 10, 0) = '\0';
143 ttyname_buf
= (char *) malloc (buflen
+ 1);
144 if (ttyname_buf
== NULL
)
151 ssize_t len
= __readlink (procname
, ttyname_buf
, buflen
);
152 if (__builtin_expect (len
== -1 && errno
== ENOENT
, 0))
158 if (__builtin_expect (len
!= -1
159 #ifndef __ASSUME_PROC_SELF_FD_SYMLINK
160 /* This is for Linux 2.0. */
161 && ttyname_buf
[0] != '['
165 if ((size_t) len
>= buflen
)
168 #define UNREACHABLE_LEN strlen ("(unreachable)")
169 if (len
> UNREACHABLE_LEN
170 && memcmp (ttyname_buf
, "(unreachable)", UNREACHABLE_LEN
) == 0)
172 memmove (ttyname_buf
, ttyname_buf
+ UNREACHABLE_LEN
,
173 len
- UNREACHABLE_LEN
);
174 len
-= UNREACHABLE_LEN
;
177 /* readlink need not terminate the string. */
178 ttyname_buf
[len
] = '\0';
180 /* Verify readlink result, fall back on iterating through devices. */
181 if (ttyname_buf
[0] == '/'
182 && __xstat64 (_STAT_VER
, ttyname_buf
, &st1
) == 0
183 #ifdef _STATBUF_ST_RDEV
184 && S_ISCHR (st1
.st_mode
)
185 && st1
.st_rdev
== st
.st_rdev
187 && st1
.st_ino
== st
.st_ino
188 && st1
.st_dev
== st
.st_dev
194 if (__xstat64 (_STAT_VER
, "/dev/pts", &st1
) == 0 && S_ISDIR (st1
.st_mode
))
196 #ifdef _STATBUF_ST_RDEV
197 name
= getttyname ("/dev/pts", st
.st_rdev
, st
.st_ino
, save
, &dostat
);
199 name
= getttyname ("/dev/pts", st
.st_dev
, st
.st_ino
, save
, &dostat
);
208 if (!name
&& dostat
!= -1)
210 #ifdef _STATBUF_ST_RDEV
211 name
= getttyname ("/dev", st
.st_rdev
, st
.st_ino
, save
, &dostat
);
213 name
= getttyname ("/dev", st
.st_dev
, st
.st_ino
, save
, &dostat
);
217 if (!name
&& dostat
!= -1)
220 #ifdef _STATBUF_ST_RDEV
221 name
= getttyname ("/dev", st
.st_rdev
, st
.st_ino
, save
, &dostat
);
223 name
= getttyname ("/dev", st
.st_dev
, st
.st_ino
, save
, &dostat
);