Passing Variable (Information) Between Programs

[MattC]

Hi,

What's the best way to pass information between one program and another? For instance, if one program collects information and the user, through the first program, opens a second program (not a second instance), what's the best/easiest way to transfer any relevant information through to the second one?

Matt

[DDRM]

Hi Matt,

Have a look at CHAIN in the manual.

The obvious and simple answer is to write the data to a temporary file, and then read it in again.

CHAIN doesn't clear the static variables, so you could pass ~26 values that way....

Otherwise you could lower HIMEM and use the space above it as a data block, into which you can write data, and subsequently read it, using indirection operators. Not for beginners, but you aren't a beginner!

Re-reading your post, it sounds as though the programs might be running at significantly different times. In that case, I'd have thought writing a data file to disk is the obvious answer.

D

[MattC]

Thanks D.

The obvious and simple answer is to write the data to a temporary file, and then read it in again.

This is the normal method I've used in the past, usually to save information both between and within programs, rather than using memory to store information. I've pretty much always stored records in files automatically whenever they are changed - hence one of my other threads regarding renaming a temp file. However, I was hoping for something more 'appropriate'.

you could lower HIMEM and use the space above it as a data block

I'll have to look into this as it's something I've never played with.

Not for beginners, but you aren't a beginner!

You seem to have more faith in my programming that I have

it sounds as though the programs might be running at significantly different times

Possibly, but not necessarily. One of the program sets I was playing with (and I use the word 'playing' deliberately) was one that uses programs that sit in the approx 32kB limit that the old BBC MICRO B used to have. However, this would necessarily require splitting the program up into smaller programs that 'chained' from one to another, but would require common but changeable data sets. The main things that need immediately transferring from one to the next are the settings, so either a settings file or the HIMEM usage seems reasonable options. As I say, this is more of an experiment than anything else.

Matt