TTYNAME(3P) POSIX Programmer's Manual TTYNAME(3P)PROLOG
This manual page is part of the POSIX Programmer's Manual. The Linux
implementation of this interface may differ (consult the corresponding
Linux manual page for details of Linux behavior), or the interface may
not be implemented on Linux.
NAME
ttyname, ttyname_r — find the pathname of a terminal
SYNOPSIS
#include <unistd.h>
char *ttyname(int fildes);
int ttyname_r(int fildes, char *name, size_t namesize);
DESCRIPTION
The ttyname() function shall return a pointer to a string containing a
null-terminated pathname of the terminal associated with file descrip‐
tor fildes. The application shall not modify the string returned. The
returned pointer might be invalidated or the string content might be
overwritten by a subsequent call to ttyname().
The ttyname() function need not be thread-safe.
The ttyname_r() function shall store the null-terminated pathname of
the terminal associated with the file descriptor fildes in the charac‐
ter array referenced by name. The array is namesize characters long
and should have space for the name and the terminating null character.
The maximum length of the terminal name shall be {TTY_NAME_MAX}.
RETURN VALUE
Upon successful completion, ttyname() shall return a pointer to a
string. Otherwise, a null pointer shall be returned and errno set to
indicate the error.
If successful, the ttyname_r() function shall return zero. Otherwise,
an error number shall be returned to indicate the error.
ERRORS
The ttyname() function may fail if:
EBADF The fildes argument is not a valid file descriptor.
ENOTTY The file associated with the fildes argument is not a terminal.
The ttyname_r() function may fail if:
EBADF The fildes argument is not a valid file descriptor.
ENOTTY The file associated with the fildes argument is not a terminal.
ERANGE The value of namesize is smaller than the length of the string
to be returned including the terminating null character.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
The term ``terminal'' is used instead of the historical term ``terminal
device'' in order to avoid a reference to an undefined term.
The thread-safe version places the terminal name in a user-supplied
buffer and returns a non-zero value if it fails. The non-thread-safe
version may return the name in a static data area that may be overwrit‐
ten by each call.
FUTURE DIRECTIONS
None.
SEE ALSO
The Base Definitions volume of POSIX.1‐2008, <unistd.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
cal and Electronics Engineers, Inc and The Open Group. (This is
POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online
at http://www.unix.org/online.html .
Any typographical or formatting errors that appear in this page are
most likely to have been introduced during the conversion of the source
files to man page format. To report such errors, see https://www.ker‐
nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2013 TTYNAME(3P)
