To add two numbers

$ expr 11 + 5

To subtract two numbers

$ expr 20 - 10

To divide two numbers

$ expr 20 / 4

To divide two numbers and want to see the remainder

$ expr 25 % 6

To multiply two numbers

$ expr 6 \* 4

To find the length of a string

$ expr length indianlinuxusergroupchennai

To check the index of character x

$ a=kanchilinuxusergroup

$ b=`expr index $a x`

$ echo $b

To extract the substring

$ a=indianlinuxusergroupchennai

$ b=`expr substr $a 21 27`

$ echo $b

To get the index of a substring from a string

$ expr substr indianlinuxusergroupchennai 21 27

To compare two expressions

$ a=50

$ b=60

$ c=`expr $a = $b`

$ echo $c

To match the number of characters of two string

$ expr linuxos : linux

$ expr linuxos : linuxo

regards,

T.Dhanasekar