Korn Shell 運算子


本教學列出了所有Korn Shell中的運算子。在這裡,大部分的運算子都是我們熟知的C語言程式設計很相似。

運算子優先順序遞減的順序如下列出:

算術和邏輯運算子:

運算子 描述
+ Unary plus
- Unary minus
!~ Logical negation; binary inversion (one's complement)
* Multiply
/ Divide
% Modulo
+ Add
- Subtract
<< Left shift
>> Right shift
== String comparison for equality
!= String comparison for non equality
=~ Pattern matching
& Bitwise "and"
^ Bitwise "exclusive or"
| Bitwise "inclusive or"
&& Logical "and"
|| Logical "or"
++ Increment
-- Decrement
= Assignment

檔案測試操作:

有以下運算子測試可用在Unix檔案中的相關聯各種屬性。

運算子 描述
-r file Checks if file is readable if yes then condition becomes true.
-w file Check if file is writable if yes then condition becomes true.
-x file Check if file is execute if yes then condition becomes true.
-f file Check if file is an ordinary file as opposed to a directory or special file if yes then condition becomes true.
-s file Check if file has size greater than 0 if yes then condition becomes true.
-d file Check if file is a directory if yes then condition becomes true.
-e file Check if file exists. Is true even if file is a directory but exists.