.\" Copyright (c) 1995 Jim Van Zandt <jrv@vanzandt.mv.com>
.\"
.\" This is free documentation; you can redistribute it and/or
.\" modify it under the terms of the GNU General Public License as
.\" published by the Free Software Foundation; either version 2 of
.\" the License, or (at your option) any later version.
.\"
.\" The GNU General Public License's references to "object code"
.\" and "executables" are to be interpreted as the output of any
.\" document formatting or typesetting system, including
.\" intermediate and printed output.
.\"
.\" This manual 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 General Public License for more details.
.\"
.\" You should have received a copy of the GNU General Public
.\" License along with this manual; if not, write to the Free
.\" Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111,
.\" USA.
.\"
.\" Modified 2001-12-13, Martin Schulze <joey@infodrom.org>
.\" Added ttyname_r, aeb, 2002-07-20
.\"
.TH TTYNAME 3 2008-07-14 "Linux" "Linux Programmer's Manual"
.SH NAME
ttyname, ttyname_r \- return name of a terminal
.SH SYNOPSIS
.nf
.B #include <unistd.h>
.sp
.BI "char *ttyname(int " fd );

.BI "int ttyname_r(int " fd ", char *" buf ", size_t " buflen );
.fi
.SH DESCRIPTION
The function
.BR ttyname ()
returns a pointer to the null-terminated pathname of the terminal device
that is open on the file descriptor \fIfd\fP, or NULL on error
(for example, if \fIfd\fP is not connected to a terminal).
The return value may point to static data, possibly overwritten by the
next call.
The function
.BR ttyname_r ()
stores this pathname in the buffer
.I buf
of length
.IR buflen .
.SH "RETURN VALUE"
The function
.BR ttyname ()
returns a pointer to a pathname on success.
On error, NULL is returned, and
.I errno
is set appropriately.
The function
.BR ttyname_r ()
returns 0 on success, and an error number upon error.
.SH ERRORS
.BR ttyname_r ():
.TP
.B EBADF
Bad file descriptor.
.TP
.B ENOTTY
File descriptor does not refer to a terminal device.
.TP
.B ERANGE
.I buflen
was too small to allow storing the pathname.
.SH "CONFORMING TO"
4.2BSD, POSIX.1-2001.
.SH "SEE ALSO"
.BR fstat (2),
.BR ctermid (3),
.BR isatty (3)
.SH COLOPHON
This page is part of release 3.44 of the Linux
.I man-pages
project.
A description of the project,
and information about reporting bugs,
can be found at
http://www.kernel.org/doc/man-pages/.