Henry,
I haven't followed this thread closely, but you can install J (and all your
J code, both general utilities and application) on the USB drive itself.
Then you run it directly from the drive, rather than trying to have the
hard-drive installation of J "find" the scripts on the USB drive.
I did this for years on CDs; we'd capture a day's worth of trading
activity in JMF files, and copy the files, the application, the utility
scripts, and the entire J installation onto a CD (using an automated
script), along with a batch file that ran everything from its working
directory (using %CD%).
This method allowed us to avoid the problem of trying to reload old data or
scripts in newer (possibly incompatible) versions of J. We were able to
identically reproduce the application as it was running on its trading
day, with all its trade data and code, for reporting, auditing, debugging,
backtesting, etc purposes.
However, I understand your situation is slightly more complex:
> above is incompatible with Edit|Configure|Folders
I, like Oleg, recommend you put your scripts under the J installation
(here, on the USB drive), so that you *can* use relative paths. You can
then use Edit|Configure|Folders to register your zip folder with that
relative path (prefix the folder destination with ~, which means "relative
to my J root"), something like Name:"zip" and Folder:"~user\zip". Would
that work for you?
If not, and you're willing fiddle with the standard library a little bit,
here's another approach you can take. Use Edit|Configure|Folders to
register your zip folder with the absolute path X:\path\to\your\scripts .
Literally use the "X:" instead of a real drive letter (I hope you don't
use an X: drive [1]), as in Name:"zip" and Folder:"X:\blah\blah\zip".
( (2{.BINPATH) , 2&}. )"_^:('X:' -: 2&{.)
Then modify ~system\extras\util\cfgread.ijs to resolve "X:" to the USB
drive letter (i.e. where J is installed & running from); specifically the
2nd to last line of the function cutfolders (the 26th line of the file)
from:
pth=. deb each (ndx+1) }.each j
to
pth=. ( (2{.BINPATH) , 2&}. )"_^:('X:' -: 2&{.) deb each (ndx+1)
}.each j
which will replace any "X:"s with the actual drive J is running from,
according to BINPATH , which is a special, executable-set variable
identifing J's binary directory. Or you could do the old MYFILENAME =.
(4!:3'') {::~ 4!:4{.;:'cutfolders' and replace BINPATH with MYFILENAME
.
Now you just have to figure out how to give the user a shortcut & icon that
points to an application (batch file) on a unknown drive....
-Dan
[1] Of course, if you do already use X: you could select another, unused
drive letter as a placeholder. I just picked X: because X looks like a
variable.
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