Pre-Requisite: Conditional Statement in Shell Script There are many operators in Shell Script some of them are discussed based on string.
- Equal operator (=): This operator is used to check whether two strings are equal. Syntax:
Operands1 = Operand2
- Example:
php
#!/bin/sh str1="GeeksforGeeks"; str2="geeks"; if [ $str1 = $str2 ]
then echo "Both string are same";
else echo "Both string are not same";
fi |
- Output:
Both string are not same
- Not Equal operator (!=): This operator is used when both operands are not equal. Syntax:
Operands1 != Operands2
- Example:
php
#!/bin/sh str1="GeeksforGeeks"; str2="geeks"; if [ $str1 != $str2 ]
then echo "Both string are not same";
else echo "Both string are same";
fi |
- Output:
Both string are not same
- Less than (\<): It is a conditional operator and used to check operand1 is less than operand2. Syntax: Operand1 \< Operand2 Example:
php
#!/bin/sh str1="GeeksforGeeks"; str2="Geeks"; if [ $str1 \< $str2 ]
then echo " $str1 is less than $str2 ";
else echo " $str1 is not less than $str2 ";
fi |
- Output:
GeeksforGeeks is not less than Geeks
- Greater than (\>): This operator is used to check the operand1 is greater than operand2. Syntax: Operand1 \> Operand2 Example:
php
#!/bin/sh str1="GeeksforGeeks"; str2="Geeks"; if [ $str1 \> $str2 ]
then echo " $str1 is greater than $str2 ";
else echo " $str1 is less than $str2 ";
fi |
- Output:
GeeksforGeeks is greater than Geeks
- Check string length greater than 0: This operator is used to check the string is not empty. Syntax:
[ -n Operand ]
- Example:
php
#!/bin/sh str="GeeksforGeeks"; if [ -n $str ]
then echo "String is not empty ";
else echo "String is empty ";
fi |
- Output:
String is not empty
- Check string length equal to 0: This operator is used to check the string is empty. Syntax:
[ -z Operand ]
- Example:
php
#!/bin/sh str=""; if [ -z $str ]
then echo "String is empty ";
else echo "String is not empty ";
fi |
- Output:
String is empty