a - unary, assignment and logical operators in shell scripts Shell scripts use various operators to perform operations on variables, strings, numbers, and other data types. Common categories of operators used in shell scripts: Unary, Arithmetic, Relational, Logical, assignment, file test , string and bit operators Unary refers to the number of operands, so they take one operand. There are two unary operators + and - which indicate whether a number is positive or negativ Assignment operators are: = → simple assignment +=, -=, *=, /=, %= → compound assignments Logical Operators: && → logical AND || → logical OR ! → logical NOT
b - Arithmetic relational and string operators in shell scripts Arithmetic Operators: → addition → subtraction * → multiplication / → division (integer division only) % → modulus (remainder of division) ++ → increment -- → decrement Relational Operators: -lt or → less than -gt or → greater than -le or = → less than or equal to -ge or = → greater than or equal to -eq or == → equal to (in arithmetic context) -ne or!= → not equal to String Operators: = or == → equal to != → not equal to → greater than (in ASCII order) → less than (in ASCII order)
c - file test and bit operators in shell scripts File Test Operators: -e → file exists -f → file is a regular file -d → directory exists -r → file is readable -w → file is writable -x → file is executable -s → file has non-zero size Bitwise operators are used to perform operations on individual bits of a number in shell scripting. common bitwise operators: & → bitwise AND | → bitwise OR ^ → bitwise XOR (exclusive OR) ~ → bitwise NOT (negation) → left shift → right shift