Why did we limit the command window history length?

Daniel asked why the size of the history seems to have a limit of around 256K in VFP9, but no limit in VFP7 (or VFP8).

It was limited to fix this bug report from a customer Oct 2003.

Things to notice about the bug report:

It’s just code that can be copy/pasted/run with no fuss
It’s a bare minimum of code: not multimegabyte files of code (A 4 GigHz processor can execute about a billion instructions per second. Which one of those billions has the problem?)
It clearly demonstrates the issue
It says what Observed, and Expected behaviors are

(1) Run these commands from a new .PRG:

COPY FILE HOME(7) + [_COMMAND.PRG] TO HOME(7) + [_COMMAND.mine]

STRTOFILE(REPLICATE([MODIFY COMMAND test]+CHR(13)+ ;

[MODIFY FORM test]+CHR(13)+[? VERSION()]+CHR(13), ;

199999),HOME(7) + [_COMMAND.BAK])

o = NEWOBJECT([_shellexecute],HOME() + [\ffc\_environ.vcx])

o.shellexecute(HOME(7),HOME(7),[])

(2) You now have a Windows Explorer window open to your user data directory. Delete _COMMAND.PRG and then rename _COMMAND.BAK to COMMAND.PRG.

(4) Open VFP again...

=== OBSERVED ===

VFP takes a long time to start and when it does, it is using about 325megs of memory.

=== EXPECTED ===

Either a linearly increasing memory usage or limiting _command.prg to a sensible size like 1 MB.

=== COMMENTS ===

To clean up, exit VFP, delete _COMMAND.PRG and rename _command.MINE to _COMMAND.PRG

Comments

Anonymous
January 27, 2006
Hello Calvin,
When using the Environment Manager Task Pane in VFP9 SP1, how can I get the command window to reload the previous command set when changing from one project to another. Each project is stored in a separate folder with its own foxuser.dbf.
Thanks,
Kent
Anonymous
January 27, 2006
Hi Kent, Unfortunately, the Command window contents are initialized only when the Command window is first shown. You could perhaps use a project hook to change _command.prg contents and shut/down/restart VFP