File handling/string size

[Kiwi]

What are the practical limits of importing an entire file into a string.

Is there a limit to the length of the string that can be handled?

[Dalsor]

There really isn't a limitation.

[Ökii]

I'd have guessed that you might be restricted by phps memory limit and (depending on your desired usage) maybe post max size and upload max filesize.

Vague defaults would point somewhere in the regions of

32MB script memory allowance
8MB post
2MB upload

Which should be enough for most tasks