HISTORY lessons ...

[MaartenG]

The behaviour of HISTORY is in some aspects different from the descriptions in the helpfiles:

/A Add a command to the history list. This performs the same function as the Ctrl-K key at the command line.

If you try - for example - to add echo %PATH to the history list, HISTORY /A echo %PATH will expand the %PATH varaible before adding it to the history list. Ctrl-K will add the original "echo %PATH" to the list.

Workaround: use backquotes around the command, like this:

HISTORY /A `echo %PATH`

In my opinion this is something the HISTORY command should take care of.


Furthermore, consider these two batchfiles:

@history /F
@history /A echo Hoi
@delay 1

@history

@history /F
@KEYSTACK /W3 "echo Hoi"
@delay 1
@KEYSTACK /W3 Ctrl-K
@delay 1

@history

(I had to add some delays because of timing issues)

In the first script there is a echo Hoi in the history list; in the second there is nothing, except when you quit the batch-file. Then it *is* on the history list....

Workaround: Couldn't find one.


And then there is the %@HISTORY function.
Don't try echo %@HISTORY[0]. It will cause a loop, because it will expand echo %@HISTORY[0] to echo echo %@HISTORY[0] ,etcetera.

Workaround: use "@" to prevent this command from being added to the history list, like this:

@echo %@HISTORY[0]

Or, if you want a certain sequence of commands to be re-executed:

DO nmbr = 12 to 7 BY -1
   @%@HISTORY[%nmbr]
ENDDO