NAME

       ttyname, ttyname_r - find the pathname of a terminal

SYNOPSIS

       #include <unistd.h>

       char *ttyname(int fildes);

       int ttyname_r(int fildes, char *name, size_t namesize);

DESCRIPTION

       The  ttyname()  function  shall  return a pointer to a string containing a null-terminated
       pathname of the terminal associated with file descriptor  fildes.  The  return  value  may
       point to static data whose content is overwritten by each call.

       The  ttyname()  function  need  not  be  reentrant.  A function that is not required to be
       reentrant is not required to be thread-safe.

       The ttyname_r()  function  shall  store  the  null-terminated  pathname  of  the  terminal
       associated  with the file descriptor fildes in the character array referenced by name. The
       array is namesize characters long and should have space for the name and  the  terminating
       null character. The maximum length of the terminal name shall be {TTY_NAME_MAX}.

RETURN VALUE

       Upon  successful  completion,  ttyname()  shall return a pointer to a string. Otherwise, a
       null pointer shall be returned and errno set to indicate the error.

       If successful, the ttyname_r() function shall return  zero.  Otherwise,  an  error  number
       shall be returned to indicate the error.

ERRORS

       The ttyname() function may fail if:

       EBADF  The fildes argument is not a valid file descriptor.

       ENOTTY The fildes argument does not refer to a terminal.

       The ttyname_r() function may fail if:

       EBADF  The fildes argument is not a valid file descriptor.

       ENOTTY The fildes argument does not refer to a terminal.

       ERANGE The  value  of  namesize  is  smaller  than the length of the string to be returned
              including the terminating null character.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       None.

RATIONALE

       The term ``terminal'' is used instead of the historical term ``terminal device'' in  order
       to avoid a reference to an undefined term.

       The  thread-safe  version places the terminal name in a user-supplied buffer and returns a
       non-zero value if it fails. The non-thread-safe version may return the name  in  a  static
       data area that may be overwritten by each call.

FUTURE DIRECTIONS

       None.

SEE ALSO

       The Base Definitions volume of IEEE Std 1003.1-2001, <unistd.h>

COPYRIGHT

       Portions  of  this  text  are  reprinted  and  reproduced in electronic form from IEEE Std
       1003.1, 2003 Edition, Standard for Information Technology  --  Portable  Operating  System
       Interface  (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 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 .