ptsname(3) — Linux manual page
ptsname(3) Library Functions Manual ptsname(3)
NAME
ptsname, ptsname_r - get the name of the slave pseudoterminal
LIBRARY
Standard C library (libc, -lc)
SYNOPSIS
#include <stdlib.h>
char *ptsname(int fd);
int ptsname_r(int fd, char buf[.buflen], size_t buflen);
Feature Test Macro Requirements for glibc (see
feature_test_macros(7)):
ptsname():
Since glibc 2.24:
_XOPEN_SOURCE >= 500
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
the file descriptor 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, an error number
is returned 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.
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 │
└──────────────────────┴───────────────┴────────────────────────┘
VERSIONS
A version of ptsname_r() 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.
STANDARDS
ptsname():
POSIX.1-2008.
ptsname_r() is a Linux extension, that is proposed for inclusion
in the next major revision of POSIX.1 (Issue 8).
HISTORY
ptsname():
POSIX.1-2001. glibc 2.1.
ptsname() is part of the UNIX 98 pseudoterminal support (see
pts(4)).
SEE ALSO
grantpt(3), posix_openpt(3), ttyname(3), unlockpt(3), pts(4),
pty(7)
COLOPHON
This page is part of the man-pages (Linux kernel and C library
user-space interface documentation) project. Information about
the project can be found at
⟨https://www.kernel.org/doc/man-pages/⟩. If you have a bug report
for this manual page, see
⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
This page was obtained from the tarball man-pages-6.9.1.tar.gz
fetched from
⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on
2024-06-26. If you discover any rendering problems in this HTML
version of the page, or you believe there is a better or more up-
to-date source for the page, or you have corrections or
improvements to the information in this COLOPHON (which is not
part of the original manual page), send a mail to
man-pages@man7.org
Linux man-pages 6.9.1 2024-05-02 ptsname(3)
Pages that refer to this page: TIOCPKT(2const), getpt(3), grantpt(3), posix_openpt(3), unlockpt(3), pts(4), pty(7)