Modifying Line Characteristics

Modifying Line Characteristics

You can modify TTY line characteristics using an IRIX editor, such as vi, to edit /etc/inittab.

The /etc/inittab file contains configuration instructions for the /etc/init command. The general format of a line entry in the /etc/inittab file is as follows:

identification:level:action:process

The four colon-separated fields are as follows:

identification: A unique one or two character identifier for the line entry.
level: The run-level(s) in which the entry is to be performed.
action: How /etc/init treats the process field (refer to the inittab(4) reference page for complete information).
process: The shell command to be executed.

/etc/inittab contains several entries that spawn getty processes. The following example is a selection of such entries from a sample /etc/inittab:

t1:23:respawn:/etc/getty -s console ttyd1 co_9600 
t2:23:respawn:/etc/getty ttyd2 co_9600

There are at least three things you might want to do to an inittab entry for a TTY line:

Change the action. Two actions that apply to TTY lines are ''respawn'' and ''off'' (see the inittab(4) reference page for complete information on this field).
Add or change arguments to /etc/getty in the process field. A frequently used argument is -tnn. This tells getty to hang up if nothing is received within nn seconds. It's good practice to use the -t argument on dialup lines.
Add or change comments. You can start your comments after a pound sign (#), and insert comments inline after a semi-colon (;).