# Bash programming

## Conditional operators

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 |`

## For loops

For loops

A loop over integers:

`for ((i=1;i<=10;i+=1)); do`

`echo $i`

`done`

## While loops

While loops

`myvar=0`

`while [ $myvar -le 10 ]`

`do`

` echo $myvar`

` myvar=$(( $myvar + 1 ))`

`done`