ctermid(3S)                                           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.

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
     refers to the terminal if used as a filename.  For this
     reason, ttyname is useful only if the process already has at
     least one file open to a terminal.

SEE ALSO
     ttyname(3C)























January 1992                                                    1