The origin some from, unix, minix, and all other *nix or postix type operating systems.
The standard accepted way to pronouce the word phonetically,
Please accept they are both correct, there is a more popular way (Lihn-Ex), and a way which immitates the accept of Linus Travoids pronouces it (Line-Ex).
Think of some other words, we have GIF, which the creator says should be prounced like JIF, but everyone prounces like gift. We also have the example of Jalapeno, Do you pronouce the word using it spanish prounciation, or do to pronouce it like an american word. I bet you pronouce it with a J sounding like an H, but the rest of the word with english vowel sounds.