ttyname(3C)                    DG/UX 5.4R3.00                    ttyname(3C)


NAME
       ttyname, ttynamer, isatty - find name of a terminal

SYNOPSIS
       #include <stdlib.h>

       char *ttyname (int fildes);

       char *ttynamer (int fildes, char *buffer, int buflen);

       int isatty (int fildes);

DESCRIPTION
       ttyname and ttynamer return a pointer to a string containing the
       null-terminated pathname of the terminal device associated with file
       descriptor fildes.  Instead of returning static data, ttynamer
       returns the string into the location pointed to by buffer. The return
       value of ttynamer is the same as buffer. buffer has a length of
       buflen characters.  If ttynamer detects an error, a NULL is returned
       and errno is set to indicate the error.

       isatty returns 1 if fildes is associated with a terminal device, 0
       otherwise.


   Considerations for Threads Programming
                     +----------+-----------------------------+
                     |          |                      async- |
                     |function  | reentrant   cancel   cancel |
                     |          |              point    safe  |
                     +----------+-----------------------------+
                     |isatty    |     Y          N        N   |
                     |ttyname   |     N          -        -   |
                     |ttynamer |     Y          Y        N   |
                     +----------+-----------------------------+

FILES
       /dev/*

DIAGNOSTICS
       ttyname and ttynamer return a NULL pointer if fildes does not
       describe a terminal device in directory /dev.

   Errors
       If the following condition occurs, ttyname, ttynamer, and isatty
       return NULL and set errno to the corresponding value:

       [ERANGE]  The value of buflen is smaller than the length of the
                 string to be returned.

       [EBADF]   The value of fildes is not a valid file descriptor.

       [ENOTTY]  The value of fildes does not refer to a terminal device.




Licensed material--property of copyright holder(s)                         1

ttyname(3C)                    DG/UX 5.4R3.00                    ttyname(3C)


SEE ALSO
       reentrant(3), ttyslot(3C), ttysrch(4M).

NOTES
       The function ttynamer is available only in the shared library,
       libc.so.

       The return value for ttyname and isatty points to static data whose
       content is overwritten by each call.
















































Licensed material--property of copyright holder(s)                         2