(probably) silly question about teriyaki sauce

[Toowittoowoo]

I am trying to cook more salmon and lots of the recipes I have found use teriyaki sauce, but only about 2tbsp. If I was buy some how long would it say okay to use in the fridge? Is it like a pasta sauce (which I'd only keep for a few days) or like pesto (which I keep for a few weeks) or like soy sauce (which I keep on the shelf forever!)?

Does anyone regularly use teriyaki sauce and know or know what it is make out of so I could make a smaller amount myself?

dh uses it and says it is more like a soy sauce so will keep for ages

www.food.com/recipe/restaurant-teriyaki-sauce-133751 - this recipe makes it with soy sauce

It's got soy, saki and rice wine (can't remember what else) so will keep for ages like soy does rather than in the fridge like pasta sauce.

soy sauce, saki and mirin I think