HP-UX System Administrator's Guide: Configuration Management

# /usr/sbin/ch_rc -a -p NOLOGIN=1 /etc/default/security
# /usr/sbin/ch_rc -a -p NOLOGIN=0 /etc/default/security
Changing Login Special Characters
As many users discover to their frustration, UNIX was originally developed on TeleType
machines that had no backspace operation. Consequently, the process of editing input
data was performed by printing characters: #, delete one character and @, delete the
line. Interrupt was defined as Rubout (ASCII DEL). This situation has carried over to
the process of logging in to a system. #, @, and DEL are still the HP-UX default login
control characters today.
Once they have logged in, users get around this inconvenience by including the stty
command in their .profile and .login scripts to change DEL, #, and @ to commonly
used control characters, such as ETX (Ctrl-C), backspace (Ctrl-H), and NAK (Ctrl-U),
respectively.
You can change the login control characters used by such programs as getty, rlogin,
ssh, and telnet. To do this, you use stty to set the desired parameters on a special
device file named /dev/ttyconf. See stty(1) for details.
The /dev/ttyconf file provides a way to change the default behavior for all logins
by all users. /dev/ttyconf represents a terminal device and maintains a set of all the
terminal control characters that can be displayed by stty. The parameters of any
terminal device file can be viewed and modified by passing the file as input to the stty
command.
When a system is rebooted, the contents of /dev/ttyconf are reset to the default
values, as displayed here by stty with the -a option:
# stty -a < /dev/ttyconf
min = 4; time = 0;
intr = DEL; quit = ^\; erase = #; kill = @
eof = ^D; eol = ^@; eol2 <undef>; swtch <undef>
stop = ^S; start = ^Q; susp <undef>; dsusp <undef>
werase <undef>; lnext <undef>
To change any of the displayed parameters, execute stty with the appropriate options.
For example, to change the system defaults for intr, erase, and kill to Ctrl-C,
Ctrl-H, and Ctrl-U, respectively, enter the command:
# stty intr ^C erase ^H kill ^U < /dev/ttyconf
To see just the variations from the defaults, enter stty without options:
# stty < /dev/ttyconf
intr = ^C; erase = ^H; kill = ^U;
swtch <undef>;
Unlike the other login commands, the getty command does not automatically use
/dev/ttyconf; it requires the -f option. In the /etc/inittab file, add the -f option
to each getty command. The next time the terminal device is reopened, getty will
Changing Login Special Characters 37