Eleven Basic Commands
To work properly, all terminals must have the following eleven commands. Termcap descriptions that have only these eleven basic descriptions usually work, although they lack extra features such as function keys and video attributes. These eleven descriptions form the core of the termcap description.
Windows: Although the Ingres forms‑based tools are generally run on an 80 x 25 monitor, Ingres runs on a monitor larger than 80 x 25 (to a maximum of 200 x 100). Applications can be created to use the entire larger-size screen. To enable use of a larger screen, change the co and li entries in the termcap file to the correct values for your screen.
The eleven commands are as follows:
co
The number of columns on the screen. Without this command there is no way to know how wide to make a form. This command is numeric and must always be followed by a number.
VT100 Example: co#80
li
The number of rows down the screen. This command is numeric and must always be followed by a number.
VT100 Example: li#24
bs
This terminal can backspace using Control-H. This is a Boolean command. Include it if your terminal can backspace using Control‑H.
bc
Sequence to use if the terminal does not use Control-H. You cannot use bc and bs together.
cd
Clears to the end of the display. Sequences to clear everything from the cursor down.
VT100 Example: cd=\E[J
ce
Clears to the end of the line. Sequences to clear everything from the cursor to the end of the line. (Not used in Windows environment.)
VT100 Example: ce=\E[K
cl
Clears the entire screen. (Not used in Windows environment.)
VT100 Example: cl=\E[;H\E[2J
cm
Moves the cursor to an Ingres-specified location. For more information and examples of this command, see the discussion following this table.
nd
Nondestructive space. This string specifies the command for moving the cursor right one space without overwriting the contents of the screen at that point.
VT100 Example: nd=\E[C
is
Terminal initialization string. This includes any sequences needed to set up the terminal prior to running a forms program. (Not used in Windows environment.)
VT100 Example:
is=\E\E[?3l\E[?4l\E[?7l\E[?8h
This terminal initialization string example does the following:
• \E puts the terminal in keypad numeric mode.
• \E[?3l puts terminal into 80‑column mode.
• \E[?4l puts terminal into jump mode.
• \E[?7l turns wraparound off.
• \E[?8h turns on autorepeat.
The command is not always needed, but for most terminals it is needed for tailoring the setup to your needs.
tc
Entry of a similar terminal. It allows you to use all the capabilities listed for another terminal without rewriting them. This command is actually optional, but is so useful that it has been listed as one of the basic commands. This capability must always be the last capability in the description. This rule, which exists so that duplicated commands can be unambiguously defined, is the only exception to the general rule that commands can be presented in any order.
Example:
(tek4115): dk|tk4115|tek‑4115|tektronix4115:\:ld@:tc=vt100f:
In this example, the tek4115 is given all the commands from the vt100f description, except the ld command to initialize the boxing characters. Proper use of this command can make writing termcap descriptions much easier.