Winrun redux

Several months ago, I wrote about using the program WINRUN in order to send data to Priority from a computer that is not running Priority. I wrote a program in Delphi that would accept barcodes (as read from a dumb barcode reader) and then would transmit them to Priority, invoking a procedure that could handle these barcodes. By the time I wrote that blog entry (in November), the Delphi program was working as designed.

That is, working until about a month ago, when we upgraded our version of Priority from 18.2 to 21.1 (a giant step that caused all kinds of problems). At first it seemed that the only change necessary to my program was to enclose the procedure name with quotation marks, but unfortunately this transpired to be not true. The program would work on a computer that was running Priority but would not work on a computer that was connected to the network and could access the Priority directories but was not running Priority.

With hindsight and after rereading the documentation, I could see that the problem was with accessing the tabula.ini file. Documented was a change in the environmental variable required for the program. Originally the variable was called TABULAINI and as I wrote then, this only has to be done once on the computer. In the mean time, the name of this variable has been changed to TABULAINIORIG (one might ask why this was done; I presume that the answer would be 'davka', a wonderful Hebrew word that supposedly means 'precisely', but has the connotation of being contrary).

Even after I changed the value of the environmental variable, my program still would not work. I had noticed before that the date of the file tabula.ini would change every time that it was accessed, but it hasn't changed since the end of May. This no doubt explains why the program doesn't work. But why?

Today I had the insight to run the SET command (without parameters) on the computer: this lists all the environmental variables that had been defined on the computer. TABULAINIORIG was not there. I have been using a batch file to check WINRUN, and indeed the first command was SET TABULAINIORIG = x:\1\tabula.ini as per the book. I added the variable again, and after unsuccessfully running the batch file, I ran SET again - and the variable that I had just added had disappeared! It seems that WINRUN 'eats' this environmental variable which is really strange behaviour.

As by this time I had removed the SET command from the batch file, I typed it in manually. Then I ran the batch file - and it worked! I ran SET again and saw that now there was a variable tabulainiorig as well as TABULAINIORIG; it seems that WINRUN wants its environmental variable in lower case!

I changed the Delphi program so that instead of setting the (wrong) environmental variable only once at program start-up, the two variables are set immediately prior to running WINRUN (I'm not taking a chance with the upper/lower case problem). And now the program works again.