C Shell運算子


本教學列出了所有C Shell的運算子。在這裡,大部分的運算子都是跟C語言程式設計很相似。

運算子優先順序遞減的順序如下:

算術和邏輯運算子:

運算子 描述
( ) Change precedence
~ 1's complement
! Logical negation
* 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
*= Multiply left side by right side and update left side
/= Divide left side by right side and update left side
+= Add left side to right side and update left side
-= Subtract left side from right side and update left side
^= "Exclusive or" left side to right side and update left side
%= Divide left by right side and update left side with remainder

檔案測試操作:

有以下操作測試與Unix檔案相關聯的各種屬性。

操作符 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.
-z 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.
-o file Check if user owns the file. It returns true if user is the owner of the file.