The foreman says if this happens he won't be a " happy camper."

工头说，如果发生这种情况， 他就不是一个“快乐的露营者” 。

He says, " If anything is unaccounted for, I won't be a happy camper."

他说，“如果有什么不明之处， 我就不会成为一个快乐的露营者。

If anything is unaccounted for, I won't be a happy camper.

如果有什么不明之处，我将不会是一个快乐的露营者。

It's an informal expression that means I won't be happy: " I won't be a happy camper, " I won't be very pleased with that situation.

这是一个非正式的表达方式，意思是我不会开心：“我不会成为一个快乐的露营者，”我不会对这种情况感到非常满意。