Hi i found the following code in a date calculation script.

if ((!(year%100))); then
((!(year%400))) && leap=1
else
((!(year%4))) && leap=1
fi
I have not find such an use of if statement till now.
As for my knowledge this is the syntax of if statement

if [ condition_A ]
then
code to run if condition_A true
elif [ condition_B ]
then
code to run if condition_A false and condition_B true
fi

Can any one tell me how the above code works.


cheers
RRK

That is ksh the (( .. )) construct: it is equivalent to let for arithmetic operations.

$(( .. )) lets you assign the result to a variable.

see man ksh for more information.