WHDLoad transfer script from archive to DH0 doesn't work

[Foebane]

I am trying to write a script that will examine the contents of a WHDLoad archive (with any name, hence the first line) and to see if the folder of the game exists in a folder on DH0. If it doesn't, then I want it to copy those files to that folder. The second part of the script will then run the game from DH0 instead of the archive, which is read-only.

The problem is, I am rusty on such things and thought I could approach it this way:

s:spat cd #?.dir
assign >nil: dh0:games/b/blackviper
if warn
  copy all to dh0:games/b/blackviper
endif
cd dh0:games/b/blackviper
wbrun blackviper

But the assign completely fails. What am I doing wrong?

EDIT: I forgot to put "exists" at the end of the assign, but when I added it, it still didn't work.

[torsti76]

assign >NIL: blackviper: dh0:games/b/blackviper

You forgot to tell assign what drive name you wanted your path to be assigned to.

Also, while testing something like this, it may prove beneficial to leave out the >NIL: first. Redirecting to NIL: effectively "swallows" all error messages.

[torsti76]

To check if a folder exists, rather than doing an assign, I'd try:

failat 21 (don't know the error level really, you'd have to look it up}
dir >NIL: dh0:/path/to/game
if warn
...
failat (whatever it was before)

[daxb]

If you want to check for exists of file/directory then use IF EXISTS. See https://wiki.amigaos.net/wiki/AmigaO...d_Reference#IF

[Foebane]

Thanks for the advice, torsti76 and daxb, especially the "IF EXISTS" command.

I changed my script to this:

s:spat cd #?.dir
if not exists dh0:games/b/blackviper
  copy all to dh0:games/b
endif
cd dh0:games/b/blackviper
wbrun blackviper

And after testing, it seems to work. The first time I booted, it copied the files over then ran, and rebooting made it run directly. So I think that's a success. I've yet to test it on my other games, but I see no problems now.