How to pull out numbers from a text file?

I have a large text file containing sentences, paragraphs, etc. I need a script that scans through the text file and create an array of only the numbers contained in the text file.

[Walter Roberson]

List the exact set of formats that numbers might occur in.

For example, is .E+30 a valid number for your purposes? If you permit 0.E+30 and you permit .0E+30 then is .E+30 also permitted? Are the + always omitted but - are used, so 0.E30 and 0.E-30 would be permitted but not +0.E30 or 0.E+30 ? Can 'e' be used instead of 'E' ? Can 'D' be used instead of 'E' ? Can there be complex numbers? If there is an integer, is it permitted for it to be followed by '.', so 12345. ? Or is '.' always followed by a digit?