Provided by: manpages-dev_4.04-2_all 

NAME
ptsname, ptsname_r - get the name of the slave pseudoterminal
SYNOPSIS
#define _XOPEN_SOURCE /* See feature_test_macros(7) */
#include <stdlib.h>
char *ptsname(int fd);
#define _GNU_SOURCE /* See feature_test_macros(7) */
#include <stdlib.h>
int ptsname_r(int fd, char *buf, size_t buflen);
DESCRIPTION
The ptsname() function returns the name of the slave pseudoterminal device corresponding to the master
referred to by fd.
The ptsname_r() function is the reentrant equivalent of ptsname(). It returns the name of the slave
pseudoterminal device as a null-terminated string in the buffer pointed to by buf. The buflen argument
specifies the number of bytes available in buf.
RETURN VALUE
On success, ptsname() returns a pointer to a string in static storage which will be overwritten by
subsequent calls. This pointer must not be freed. On failure, NULL is returned.
On success, ptsname_r() returns 0. On failure, a nonzero value is returned and errno is set to indicate
the error.
ERRORS
EINVAL (ptsname_r() only) buf is NULL.
ENOTTY fd does not refer to a pseudoterminal master device.
ERANGE (ptsname_r() only) buf is too small.
VERSIONS
ptsname() is provided in glibc since version 2.1.
ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7).
┌─────────────┬───────────────┬────────────────────────┐
│ Interface │ Attribute │ Value │
├─────────────┼───────────────┼────────────────────────┤
│ ptsname() │ Thread safety │ MT-Unsafe race:ptsname │
├─────────────┼───────────────┼────────────────────────┤
│ ptsname_r() │ Thread safety │ MT-Safe │
└─────────────┴───────────────┴────────────────────────┘
CONFORMING TO
POSIX.1-2001, POSIX.1-2008.
ptsname() is part of the UNIX 98 pseudoterminal support (see pts(4)).
ptsname_r() is a Linux extension. A version of this function is documented on Tru64 and HP-UX, but on
those implementations, -1 is returned on error, with errno set to indicate the error. Avoid using this
function in portable programs.
SEE ALSO
grantpt(3), posix_openpt(3), ttyname(3), unlockpt(3), pts(4), pty(7)
COLOPHON
This page is part of release 4.04 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
http://www.kernel.org/doc/man-pages/.
2015-08-08 PTSNAME(3)