PROLOG

       This  manual  page  is part of the POSIX Programmer's Manual.  The Linux implementation of
       this interface may differ (consult the corresponding Linux  manual  page  for  details  of
       Linux behavior), or the interface may not be implemented on Linux.

NAME

       ptsname — get name of the slave pseudo-terminal device

SYNOPSIS

       #include <stdlib.h>

       char *ptsname(int fildes);

DESCRIPTION

       The  ptsname()  function  shall  return  the  name  of  the  slave  pseudo-terminal device
       associated with a master pseudo-terminal device. The fildes argument is a file  descriptor
       that  refers  to  the  master  device.  The ptsname() function shall return a pointer to a
       string containing the pathname of the corresponding slave device.

       The ptsname() function need not be thread-safe.

RETURN VALUE

       Upon successful completion, ptsname() shall return a pointer to a string which is the name
       of  the  pseudo-terminal slave device. Upon failure, ptsname() shall return a null pointer
       and may set errno.  This could occur if fildes is an invalid file  descriptor  or  if  the
       slave device name does not exist in the file system.

       The  application  shall  not  modify  the  string  returned. The returned pointer might be
       invalidated or the string content might be overwritten by a subsequent call to  ptsname().
       The  returned  pointer  and  the  string  content might also be invalidated if the calling
       thread is terminated.

ERRORS

       The ptsname() function may fail if:

       EBADF  The fildes argument is not a valid file descriptor.

       ENOTTY The file associated with the  fildes  argument  is  not  a  master  pseudo-terminal
              device.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       None.

RATIONALE

       See the RATIONALE section for posix_openpt().

FUTURE DIRECTIONS

       None.

SEE ALSO

       grantpt(), open(), posix_openpt(), ttyname(), unlockpt()

       The Base Definitions volume of POSIX.1‐2017, <stdlib.h>

COPYRIGHT

       Portions  of  this  text  are  reprinted  and  reproduced in electronic form from IEEE Std
       1003.1-2017, Standard for Information Technology -- Portable  Operating  System  Interface
       (POSIX),  The  Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by
       the Institute of Electrical and Electronics Engineers, Inc and The  Open  Group.   In  the
       event  of  any  discrepancy  between this version and the original IEEE and The Open Group
       Standard, the original IEEE and The Open Group  Standard  is  the  referee  document.  The
       original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

       Any  typographical  or  formatting errors that appear in this page are most likely to have
       been introduced during the conversion of the source files to man page  format.  To  report
       such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .