Generates the path name of the controlling terminal.
Standard C Library (libc.a)
#include <stdio.h>
char *ctermid ( String)
char *String;
The ctermid subroutine generates the path name of the controlling terminal for the current process and stores it in a string.
The difference between the ctermid and ttyname subroutines is that the ttyname subroutine must be handed a file descriptor and returns the actual name of the terminal associated with that file descriptor. The ctermid subroutine returns a string (the /dev/tty file) that refers to the terminal if used as a file name. Thus, the ttyname subroutine is useful only if the process already has at least one file open to a terminal.
| Item | Description |
|---|---|
| String | If the String parameter is a null pointer, the string
is stored in an internal static area and the address is returned.
The next call to the ctermid subroutine overwrites the contents
of the internal static area. If the String parameter is not a null pointer, it points to a character array of at least L_ctermid elements as defined in the stdio.h file. The path name is placed in this array and the value of the String parameter is returned. |