ctermid(3S)          STANDARD I/O FUNCTIONS           ctermid(3S)



NAME
     ctermid - generate file name for terminal

SYNOPSIS
     #include <stdio.h>

     char *ctermid (char *s);

DESCRIPTION
     ctermid generates the path name 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 Lctermid elements; the path name is  placed  in  this
     array  and  the  value  of  s  is  returned.   The  constant
     Lctermid is defined in the stdio.h header file.

SEE ALSO
     ttyname(3C).

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  file  name.   Thus
     ttyname  is  useful only if the process already has at least
     one file open to a terminal.
























          Last change: C Programming Language Utilities         1