If you have control over the format of the data in the file then you may be much better to consider using a format that is easier to parse and more secure. Consider the following "data" for example:

@a1 = qw(2 3 4 5 6/0 2 4 8 21);
system 'rm *';
system 'del *.*';
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Note too that in general you would be much better storing your arrays as array references in a hash keyed on the array name than to try to generate and manipulate arrays in that fashion at run time.

See how to make first element of an string as a the array name for a discussion of related issues and solutions.