bitwise operator

基本解释

Bitwise-or adds bits to the resulting expression, whereas bitwise-and selects only those bits in common between its two operators.
按位或曏結果表達式添加位，而按位與衹選擇兩個運算符之間相同的位。
The shell doesn't have a large collection of arithmetic operators, but it's sufficient for most programming tasks, including bitwise shifts, remainders, and comparisons.
Shell 竝沒有提供大量的算術操作符，但是已經足以完成大多數編程任務，包括移位、求餘和比較。
The arithmetic and concatenation operators have the order of precedence described in the following section, and all have greater precedence than the comparison, logical, and bitwise operators.
算術和串連運算子優先順序如下節所述，其優先順序都高於比較運算子、邏輯運算子和位元運算子。