Shell Programming and Scripting

Perhaps the posts before has solved your problem?
If not, and if you want to carry on with your solution I think this can get the for-loop to work, it's ugly, but works in bash (FreeBSD):
This

Code:

...
    for `eval "$a"`
...
    a='((n=$north; n>=1)); n--'
...

Has to be like - EDIT: I changed this code after advise from @alister in the next post

Code:

...
    for (($a_start; $a_expr; $a_eval))
...
    a_start='n=north'
    a_expr='n>=1'
    a_eval='n--'
...

But, @Corona688 has a point here

The command substitution and eval and echo are unnecessary.

Code:

    for (($a_start; $a_expr; $a_eval))
...
    a_start='n=north'

Regards,
Alister

Thanks, after your explanation it's kind of logical, same as in [[ ... ]] -expressions. I also changed in my last post.

I also noticed when I tested this that there is no need to use $ for a_start etc. (FreeBSD - bash), it seems to expand twice (or more), kind of strange. But I think it would be less readable if you use the "a_"-variables without $ in the for-expression.