Display contents of .txt file

[squidge]

But if you don't know the maximum line length, how much would you read?

Depends on the requirement. If it was 20 lines, then I would read 20 * 132 as a starting point. If I don't see 20 new lines in the buffer, then I would guess at another figure depending on how many lines I did see (appending to the data already in the buffer), and keep doing that until I matched the requirement.

[wysota]

Effectively reading the whole file For instance if the whole file contained only a single line.