ttyinit, ttyrestore, erasechar, killchar - initialize and restore
terminal for I/O
The ttyinit function initializes escape(C-3) and getkey for
terminal input and output. The TERM environment variable must
contain the name of a terminal in the terminal definition. The
string TERM is used to access the terminal definition file, if
the terminal definition file is used. This can be done by the
Ttyinit reads the terminal definition named by TERM. If there is
no environment variable TERM, ttyinit returns -1. If the terminal
named by the TERM name is not defined, ttyinit returns 0 (zero).
Ttyinit returns 1 on success. Any program using getkey, escape or
termparm must first call ttyinit to determine that there is a
valid terminal type defined. If there is a valid terminal
definition file, it is loaded into program memory and used for
all calls to escape, getkey, and termparm.
Normally input is read from the keyboard one line at a time. The
ttyinit function sets the terminal driver so that characters can
be read when they are typed rather than waiting until the RETURN
key is pressed. The ttyinit function also disables character
echoing, so it is the responsibility of the program calling
ttyinit to echo typed characters.
The ttyrestore function restores the terminal state as it was
before ttyinit was called. The first time the ttyinit function is
called, it saves the current terminal state before it changes it,
and ttyrestore uses this to reset the terminal.
The erasechar function returns the character that is typed when a
character should be erased. The killchar function returns the
character that is typed when a line should be erased. The ttyinit
function disables character erasing and line killing that is
normally performed. These functions are used to determine what
characters are typed to erase a character or erase a line, so
that they can be simulated by the program using ttyinit.
The intrchar functions returns the character that is typed to
interrupt the process. Ttyinit does not disable interrupt
The functions ttyinit and ttyrestore are not utilized in the
Chapter 2, Terminal Independent I/O
C/Base Reference Manual Chapter 11, Creating Terminal Definitions