descreen

来自「ftam等标准协议服务器和客户端的源代码。」· 代码 · 共 58 行

Depending on the method you have used to connect to the Directory Service,
the system may or may not know what sort of terminal (or terminal
emulation) you are using.  If information about your terminal type is 
not available to the program when you connect initially - this will be 
the case if you connect using a PAD - the system will assume that you are 
using a standard sized screen of 24 rows of 80 columns.

The program will work quite adequately with these default settings.  There
is, however, some benefit in providing information to the system about the
type of terminal you are using, as the program attempts to use 
"inverse-video" for displaying its prompts.

The SETTINGS help screen allows you to enter or adjust your terminal type
as well as some of the values associated with your terminal.  This help 
screen displays the current settings of certain variables.  This information
might look as below:

VARIABLE     VALUE           DESCRIPTION
  NAME
termtype     vt100  The user's terminal type
invvideo        on  Prompts in inverse video if possible
cols            80  The width of the user's screen in columns
lines           24  The depth of the user's screen in lines

Having displayed the information, you will be asked if you wish to modify 
any of the settings, thus:

  Do you want to change any settings (y/n) ?

If you respond with a y, you will then be prompted in turn for the name 
of the variable you wish to modify, and the value you wish the variable 
to take.  The following dialogue would allow you to adjust the terminal type
to vt220.

  Do you want to change any settings (y/n) ?  y
  Enter name of variable you wish to modify:  termtype
  Enter value of variable:  vt220

A few notes to help you along:

Entering <CR> on its own anywhere will default to no change.

You only have to enter as many characters of the variable name as are 
sufficient to disambiguate it from other variables - in all the cases above,
a single letter suffices!

Note that adjusting the terminal type will adjust the size of screen 
variables automatically to the standard values for that terminal type.
This may do the wrong thing in the case of variable sized terminal 
emulations such as "xterm".

If you find that the terminal emulation is not behaving correctly - this 
is not uncommon - try resetting the terminal type to "dumb" for a basic 
service.

invvideo is a boolean variable, and takes values "on" and "off"