x11r4 man page for ptsname

PTSNAME(3)						     Linux Programmer's Manual							PTSNAME(3)

NAME
       ptsname, ptsname_r - get the name of the slave pseudoterminal

SYNOPSIS
       #include <stdlib.h>

       char *ptsname(int fd);
       int ptsname_r(int fd, char *buf, size_t buflen);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       ptsname():
	   Since glibc 2.24:
	       _XOPEN_SOURCE >= 500 ||
		   (_XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED)
	   Glibc 2.23 and earlier:
	       _XOPEN_SOURCE

       ptsname_r():
	   _GNU_SOURCE

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-termi-
       nated 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.  (This error is returned only for glibc 2.25 and earlier.)

       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
       ptsname():
	POSIX.1-2001, POSIX.1-2008.

       ptsname() is part of the UNIX 98 pseudoterminal support (see pts(4)).

       ptsname_r()  is a Linux extension, that is proposed for inclusion in the next major revision of POSIX.1 (Issue 8).  A version of this func-
       tion 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 4.15 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/.

								    2017-09-15								PTSNAME(3)