Unix / Linux - Korn Shell Operators

We will now discuss all the operators available in Korn Shell. Most of the operators are very similar to what we have in the C Programming language.

Operators are listed in the order of decreasing precedence −

Arithmatic and Logical Operators

Sr.No.	Operator & Description
1	+ Unary plus
2	- Unary minus
3	!~ Logical negation; binary inversion (one's complement)
4	* Multiply
5	/ Divide
6	% Modulo
7	+ Add
8	- Subtract
9	<< Left shift
10	>> Right shift
11	== String comparison for equality
12	!= String comparison for non-equality
13	=~ Pattern matching
14	& Bitwise "and"
15	^ Bitwise "exclusive or"
16	\| Bitwise "inclusive or"
17	&& Logical "and"
18	\|\| Logical "or"
19	++ Increment
20	-- Decrement
21	= Assignment

Following operators test various properties associated with a Unix file.

Sr.No.	Operator & Description
1	-r file Checks if file is readable; if yes, then the condition becomes true.
2	-w file Checks if file is writable; if yes, then the condition becomes true.
3	-x file Checks if file is executable; if yes, then the condition becomes true.
4	-f file Checks if file is an ordinary file as opposed to a directory or special file; if yes, then the condition becomes true.
5	-s file Checks if file has size greater than 0; if yes, then the condition becomes true.
6	-d file Checks if file is a directory; if yes, then the condition becomes true.
7	-e file Checks if file exists; is true even if file is a directory but exists.

unix-basic-operators.htm