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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | ATTRIBUTES | CONFORMING TO | NOTES | SEE ALSO | COLOPHON |
TTYNAME(3) Linux Programmer's Manual TTYNAME(3)
ttyname, ttyname_r - return name of a terminal
#include <unistd.h>
char *ttyname(int fd);
int ttyname_r(int fd, char *buf, size_t buflen);
The function ttyname() returns a pointer to the null-terminated
pathname of the terminal device that is open on the file descriptor
fd, or NULL on error (for example, if fd is not connected to a
terminal). The return value may point to static data, possibly
overwritten by the next call. The function ttyname_r() stores this
pathname in the buffer buf of length buflen.
The function ttyname() returns a pointer to a pathname on success.
On error, NULL is returned, and errno is set appropriately. The
function ttyname_r() returns 0 on success, and an error number upon
error.
EBADF Bad file descriptor.
ENOTTY File descriptor does not refer to a terminal device.
ERANGE (ttyname_r()) buflen was too small to allow storing the
pathname.
ENODEV File descriptor refers to a slave pseudoterminal device but
the corresponding pathname could not be found (see NOTES).
For an explanation of the terms used in this section, see
attributes(7).
┌────────────┬───────────────┬────────────────────────┐
│Interface │ Attribute │ Value │
├────────────┼───────────────┼────────────────────────┤
│ttyname() │ Thread safety │ MT-Unsafe race:ttyname │
├────────────┼───────────────┼────────────────────────┤
│ttyname_r() │ Thread safety │ MT-Safe │
└────────────┴───────────────┴────────────────────────┘
POSIX.1-2001, POSIX.1-2008, 4.2BSD.
A process that keeps a file descriptor that refers to a pts(4) device
open when switching to another mount namespace that uses a different
/dev/ptmx instance may still accidentally find that a device path of
the same name for that file descriptor exists. However, this device
path refers to a different device and thus can't be used to access
the device that the file descriptor refers to. Calling ttyname() or
ttyname_r() on the file descriptor in the new mount namespace will
cause these functions to return NULL and set errno to ENODEV.
tty(1), fstat(2), ctermid(3), isatty(3), pts(4)
This page is part of release 4.12 of the Linux man-pages project. A
description of the project, information about reporting bugs, and the
latest version of this page, can be found at
https://www.kernel.org/doc/man-pages/.
Linux 2017-05-03 TTYNAME(3)
Pages that refer to this page: ctermid(3), getttyent(3), getutent(3), isatty(3), openpty(3), ptsname(3), ttyslot(3)