CTERMID(3S)                          SysV                          CTERMID(3S)



NAME
     ctermid - generate filename for terminal

SYNOPSIS
     #include <stdio.h>
     char *ctermid (s)
     char *s;

DESCRIPTION
     ctermid generates the pathname of the controlling terminal for the
     current process, and stores it in a string.

     If s is a NULL pointer, the string is stored in an internal static area,
     the contents of which are overwritten at the next call to ctermid, and
     the address of which is returned.  Otherwise, s is assumed to point to a
     character array of at least L_ctermid elements; the pathname is placed in
     this array and the value of s is returned.  The constant L_ctermid is
     defined in the <stdio.h> header file.

DIAGNOSTICS
     Upon successful completion, the ctermid function returns the address of
     the generated pathname.  Otherwise, an empty string is returned.

NOTES
     The difference between ctermid and ttyname(3C) is that ttyname must be
     handed a file descriptor and returns the actual name of the terminal
     associated with that file descriptor, while ctermid returns a string
     (/dev/tty) that will refer to the terminal if used as a filename.  Thus
     ttyname is useful only if the process already has at least one file open
     to a terminal.

SEE ALSO
     ttyname(3C).