Name
ptsname, ptsname_r - get the name of the slave pseudoterminalLibrary
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 descriptorfd
. 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 |
T} | Thread safety | MT-Unsafe race:ptsname |
T} | 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)).