ttyname.3c (2010 09)

t
ttyname(3C) ttyname(3C)
NAME
ttyname( ), ttyname_r( ), isatty( ) - find name of a terminal
SYNOPSIS
#include <unistd.h>
char *ttyname(int fildes);
int ttyname_r(int fildes, char *buffer, size_t buflen);
int isatty(int fildes);
DESCRIPTION
ttyname() returns a pointer to a string containing the null-terminated path name of the terminal dev-
ice associated with file descriptor fildes.
isatty() returns 1 if fildes is associated with a terminal device, 0 otherwise.
Reentrant Interfaces
ttyname_r() returns the result string in the supplied buffer. The buffer is buflen characters long and
should have space for the name and the terminating null character. The maximum length of the terminal
name is
TTY_NAME_MAX.
RETURN VALUE
ttyname() returns a NULL pointer if fildes does not describe a terminal device in directory /dev
.
ttyname_r() returns a zero upon success and an error number upon failure.
ERRORS
isatty() and ttyname() fail if any of the following conditions are encountered:
[EBADF] The fildes argument is invalid.
[ENOTTY] An inappropriate I/O control operation has been attempted.
APPLICATION USAGE
The return value for
ttyname() points to static data whose content is overwritten by each call.
WARNINGS
For streams ptys,
ttyname() and isatty() do not consider master ptys to be tty devices. It should
also be noted that ttyname() returns a pointer to the master pty name for all master pty devices. This
is a result of device files being linked together.
Users of
ttyname_r() should also note that the prototype of this function has changed in this release
for conformance with the POSIX.1c Threads standard. The old prototype of ttyname_r() is supported
for compatibility with existing DCE applications only.
FILES
/dev/*
/dev/pty/*
SEE ALSO
thread_safety(5).
STANDARDS CONFORMANCE
ttyname(): AES, SVID2, SVID3, XPG2, XPG3, XPG4, FIPS 151-2, POSIX.1
ttyname_r():POSIX.1c
isatty(): AES, SVID2, SVID3, XPG2, XPG3, XPG4, FIPS 151-2, POSIX.1
HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1