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)

Linux man-pages 6.7                                2023-10-31                                         ptsname(3)