/* Determine name of a terminal.
Copyright (C) 2010-2023 Free Software Foundation, Inc.
This file is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of the
License, or (at your option) any later version.
This file is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program. If not, see . */
/* Written by Bruno Haible , 2010. */
#include
#include
#include
#include
#include
#if defined __ANDROID__
# include
#endif
int
ttyname_r (int fd, char *buf, size_t buflen)
#undef ttyname_r
{
#if defined __ANDROID__
/* On Android, read the result from the /proc file system. */
if (!isatty (fd))
/* We rely on isatty to set errno properly (i.e. EBADF or ENOTTY). */
return errno;
else if (buflen == 0)
return ERANGE;
else
{
char procfile[14+11+1];
char largerbuf[512];
ssize_t ret;
sprintf (procfile, "/proc/self/fd/%d", fd);
ret = (buflen < sizeof (largerbuf)
? readlink (procfile, largerbuf, sizeof (largerbuf))
: readlink (procfile, buf, buflen <= INT_MAX ? buflen : INT_MAX));
if (ret < 0)
return errno;
if ((size_t) ret >= buflen)
return ERANGE;
if (buflen < sizeof (largerbuf))
memcpy (buf, largerbuf, (size_t) ret);
buf[(size_t) ret] = '\0';
return 0;
}
#elif HAVE_TTYNAME_R
/* When ttyname_r exists, use it. */
/* This code is multithread-safe. */
/* On Solaris, ttyname_r always fails if buflen < 128. On OSF/1 5.1,
ttyname_r ignores the buffer size and assumes the buffer is large enough.
So provide a buffer that is large enough. */
char largerbuf[512];
# if HAVE_POSIXDECL_TTYNAME_R
int err =
(buflen < sizeof (largerbuf)
? ttyname_r (fd, largerbuf, sizeof (largerbuf))
: ttyname_r (fd, buf, buflen <= INT_MAX ? buflen : INT_MAX));
if (err != 0)
return err;
if (buflen < sizeof (largerbuf))
{
size_t namelen = strlen (largerbuf) + 1;
if (namelen > buflen)
return ERANGE;
memcpy (buf, largerbuf, namelen);
}
# else
char *name =
(buflen < sizeof (largerbuf)
? ttyname_r (fd, largerbuf, sizeof (largerbuf))
: ttyname_r (fd, buf, buflen <= INT_MAX ? buflen : INT_MAX));
if (name == NULL)
return errno;
if (name != buf)
{
size_t namelen = strlen (name) + 1;
if (namelen > buflen)
return ERANGE;
memmove (buf, name, namelen);
}
# endif
return 0;
#elif HAVE_TTYNAME
/* Note: This is not multithread-safe. */
char *name;
size_t namelen;
name = ttyname (fd);
if (name == NULL)
return errno;
namelen = strlen (name) + 1;
if (namelen > buflen)
return ERANGE;
memcpy (buf, name, namelen);
return 0;
#else
/* Platforms like mingw: no ttys exist at all. */
return ENOTTY;
#endif
}