Bash programming

Conditional operators

operator	produces true if...	no. of operands
-n	operand has non zero length	1
-z	operand has zero length	1
-d	there exists a directory whose name is operand	1
-f	there exists a file whose name is operand	1
-eq	the operands are integers and they are equal	2
-neq	the opposite of -eq	2
=	the operands are equal (as strings)	2
!=	opposite of =	2
-lt	operand1 is strictly less than operand2 (both operands should be integers)	2
-gt	operand1 is strictly greater than operand2 (both operands should be integers)	2
-ge	operand1 is greater than or equal to operand2 (both operands should be integers)	2
-le	operand1 is less than or equal to operand2 (both operands should be integers)	2

A loop over integers:

for ((i=1;i<=10;i+=1)); do
echo $i
done

myvar=0
while [ $myvar -le 10 ]
do
    echo $myvar
    myvar=$(( $myvar + 1 ))
done