Open and scroll through 42 GB text file in Mac OS X

The easiest way is to use a terminal pager. Open a terminal and run

less file.txt

or

more file.txt

Well, hexfiend is what I use, and love to use...

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If it is a text file, you just go to Views and uncheck Hexadecimal option, it will show only text.

So, for example I scrolled to line: 37802466 superfast, no glitches...