In Bash shell scripting we can perform comparison of the numbers. To perform bash compare numbers operation you need to use “test” condition within if else loop. This Post will quickly tell you how to bash compare numbers.
Operators for bash compare numbers
| Operator | Meaning | Example |
|---|---|---|
| -eq | bash compare numbers for equality Returns 0 if its equal | if [ $a -eq $b ] then |
| -ge | bash compare numbers if its greater than or equal . Result returns 0 if it’s greater than or equal | if [ $a -ge $b ] then |
| -gt | bash compare numbers if its greater. | if [ $a -gt $b ] then |
| -le | bash compare numbers if its less than or equal. | if [ $a -le $b ] then |
| -lt | bash compare numbers if its less. | if [ $a -lt $b ] then |
| -ne | bash compare numbers if its not equal or not. | if [ $a -ne $b ] then |
Detail examples of bash compare numbers operators:
1. -eq operator
This bash compare numbers operator will check the values are equal or not. If its equal it return value 0.
[root@rhel1 ~]# cat test.sh #!/bin/bash echo "enter value of a variable" read a echo "enter value of b variable" read b if [ $a -eq $b ] then echo "Returned value is:: $?" echo "a and b are equal" else echo "Returned value is:: $?" echo "a and b are not equal" fi [root@rhel1 ~]#
Execution:
[root@rhel1 ~]# sh test.sh enter value of a variable 2 enter value of b variable 3 Returned value is:: 1 a and b are not equal [root@rhel1 ~]# sh test.sh enter value of a variable 2 enter value of b variable 2 Returned value is:: 0 a and b are equal [root@rhel1 ~]#
In the above example we taken 2 and 3 for the first time at that time system returns value 1, however when we taken same values for a and b variable system returns value zero.
2. -ge operator
This bash compare numbers operator will check the values for greater than or equal . If its greater than or equal then it return value 0.
[root@rhel1 ~]# cat test1.sh #!/bin/bash #program for -ge comparing echo "enter value of a variable" read a echo "enter value of b variable" read b if [ $a -ge $b ] then echo "Returned value is:: $?" echo "a is greater than or equal to b" else echo "Returned value is:: $?" echo "a is not greater than or equal to b" fi [root@rhel1 ~]#
Output of execution:
3. -gt operator
This bash compare numbers operator will check the values for greater than. If it’s greater than, then it return value 0.
[root@rhel1 ~]# cat test2.sh #!/bin/bash #program for -gt comparing b=100 echo "enter value grater than 100" read a if [ $a -gt $b ] then echo "Very Good" else echo "You are naughty" fi
4. -le operator
This bash compare numbers operator will check the values for less than or equal . If its less than or equal then it return value 0.
#program for -le comparing b=5 echo "enter value less than or equal to 5" read a if [ $a -le $b ] then echo "You like weekdays" else echo "You are week end fan!!!!" fi [root@rhel1 ~]#
5. -lt operator
This bash compare numbers operator will check the values for less than. If it’s less than, then it return value 0.
[root@rhel1 ~]# cat test4.sh #!/bin/bash #program for -lt comparing b=0 echo "enter number with minus sign" read a if [ $a -lt $b ] then echo "Oho You are honest!!!" else echo "Go Away" fi [root@rhel1 ~]#
6. -ne operator
This bash compare numbers operator will check the values are not equal. If its not equal it return value 0.
[root@rhel1 ~]# cat test5.sh #!/bin/bash #program for -ne comparing b=0 echo "Please enter any non zero value" read a if [ $a -ne $b ] then echo "Very Nice!!!" else echo "Oh My god You have entered Zero value" fi [root@rhel1 ~]#
Execution:
[root@rhel1 ~]# sh test5.sh Please enter any non zero value 2 Very Nice!!! [root@rhel1 ~]# sh test5.sh Please enter any non zero value 0 Oh My god You have entered Zero value
To Know more about for loops,
To know more about while loops.