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Very often, the programmer or the text writer has to repeat some complex editing action over a series of similar blocks of text. This is where macros come in.
A macro is a stored sequence of commands. Any sequence of commands
you find yourself repeating is an excellent candidate for being made
into a macro. You could create a macro by editing a document that only
contains valid ne
commands and saving it, but by far the easiest way to create
a macro is to have ne
record your actions. ne
allows you
to record macros and then play them (execute the commands they contain)
many times. You can save them on disk for future use, edit them, or bind
them to any key. You could even reconfigure each key of your keyboard to
play a complex macro if you wanted to.
ne
can have any number of named macros loaded at the same time.
It can also have one unnamed macro in its current macro buffer.
The named macros are typically loaded from disk files, while the
current macro buffer is where your recorded macro is held before you
save it or record over it.
Recording a macro is very simple. The keystroke <Control>-T
starts and stops recording a macro. When you start recording a macro,
ne
clears the current macro buffer and starts recording all
your actions (with a few exceptions). You can see that you are recording
a macro if an 'R' appears on the status bar. When you stop the
recording process (again using <Control>-T), you can play the
macro with the 'Play Once' item of the 'Macros' menu or with
the <f9> key. If you want to repeat the action many times, the
Play
command allows you to specify a number of times to repeat
the macro. You can always interrupt the macro's execution with
<Control>-\.
A recorded macro has no name. It's just an anonymous sequence of
commands in the current macro buffer, and it will go away when you
exit ne
or record another macro. If you want to save your
recorded macro for future use, you can give it a name and save it with
the 'Save Macro...' menu item or the SaveMacro
command. The
macro is saved as a file in your current directory by default or
whatever directory you specify when prompted for the macro's name. If
you save it in your ~/.ne directory then it will be easy to
access it later from any other directory. The 'Open Macro...' menu item
and the OpenMacro
command load a macro from a file into the
current macro buffer just as if you just Record
ed it.
Any macro can be loaded from a file and played with the 'Play Macro...'
menu item or the Macro
command. (This won't modify any recorded
anonymous macro that may be in the current macro buffer;
OpenMacro
does that.) Useful macros can be permanently bound to a
keystroke as explained in Key Bindings. Moreover, whenever a
command line does not specify one of ne
's built in commands, it is
assumed to specify the name of a macro to execute. Thus, you can execute
macros just by typing their file names. Include a path if the macro
file's directory is different from your current directory or your
~/.ne directory.
If the first attempt to open a macro fails, ne
checks for a macro
with the given name in your ~/.ne directory. This allows you
to program simple extensions to ne
's language. For instance, all
automatic preferences macros—which are just specially named macros
that contain only commands to set preferences flags—can be executed
just by typing their names. For example, if you have an automatic
preference for the 'doc' extension for example, you can set
ne
's flags exactly as if you loaded a file ending with
'.doc' by typing the command doc#ap
.
In general, it is a good idea to save frequently used macros in
~/.ne so that you can invoke them by name without specifying
a path regardless of your current directory. On the other hand, if you
have a macro that is customized for one document or a set of documents
that you store in one directory, then you might want to save the
macro in that directory as well. If you do, then you would want to
cd
to that directory before you start ne
so that you can
access that macro without specifying a path.
If your macro has the same name as one of ne
's built-in commands,
you can only access it with the Macro
name command.
Built-in command names are always found first before ne
command
interpreter looks for macros.
The system administrator may make some macros available from
ne
's global directory. See Arguments.
Since loading a macro each time it is invoked would be a rather slow and expensive process, once a macro has been executed it is cached internally. Subsequent invocations of the macro will used the cached version.
Warning: the macro names are not case
sensitive or path sensitive. ne
only caches the file name of a
macro, not the path name, and uses a case insensitive comparison. That
is, if you invoke ~/foobar/macro, a subsequent call for
/usr/MACRO will use the cached version of ~/foobar/macro.
You can clear the cache by using the UnloadMacros
command.
See UnloadMacros.
The behaviour of macros may vary with different preferences. If the user
changes the AutoIndent and WordWrap flags, for example, new lines and new
text may not appear in the same way they would have when a macro was
recorded. Good general purpose macros avoid such problems by using the
PushPrefs
command first. This preserves the user's preferences.
Then they set any preferences that could affect their behaviour. Once
that is taken care of they get on with the actual work for which they
were intended. Finally, they use the PopPrefs
command to restore
the user's preferences. Note that if a macro is stopped before it
restores the preferences (either by the user pressing
<Control>-\ or by a command failing) then that responsibility
falls on the user.