Command Line Interface 41
Displaying Characteristics of the Command Line
The command line interface provides a pausing function. If the information to be
displayed exceeds one screen, users have three choices, as shown in Table6.
History Command
The command line interface provides a function similar to that of the DosKey.
Commands entered by users are automatically saved by the command line interface
and you can invoke and execute them at any time later. The history command buffer
is defaulted as 10. That is, the command line interface stores 10 history commands
for each user. The operations are shown in Table 7.
Cursor keys can be used to retrieve the history commands in Windows 3.X Terminal
and Telnet. However, in Windows 9X HyperTerminal, the up and down cursor keys
and do not work, because Windows 9X HyperTerminal defines the two keys
differently. In this case, use the combination keys <Ctrl+P> and <Ctrl+N> instead for
the same purpose.
Common Command Line Error Messages
Incorrectly entered commands will cause error messages to be reported to users. The
common error messages are listed in Table8.
Tabl e 6 Functions of Displaying
Key or Command Function
Press <Ctrl+C> when the display pauses Stop displaying and executing command.
Enter a space when the display pauses Continue to display the next screen of
information.
Press <Enter> when the display pauses Continue to display the next line of
information.
Tabl e 7 Retrieving History Command
Operation Key Result
Display history command display
history-command
Display history command by
user inputting
Retrieve the previous history
command
Up cursor key <> or <Ctrl+P> Retrieve the previous history
command, if there is any.
Retrieve the next history
command
Down cursor key <> or
<Ctrl+N>
Retrieve the next history
command, if there is any.
Tabl e 8 Common Command Line Error Messages
Error messages Causes
Unrecognized command ■Cannot find the command
■Cannot find the keyword
■Wrong parameter type
■The value of the parameter exceeds the range
Incomplete command The command is incomplete.
Too many parameters Too many parameters have been entered.
Ambiguous command The parameters entered are not specific.