String to number

[team@whatalooker.com 0]

Hello,

 

I am reading data from a text file. It has 3 columns. 2 columns contains string and the 3rd one contains integer.

I load each piece of data into a separate variable and then I need to use the third variable as integer #duration In my specific case it stands for a duration of a video. Then I am trying to use $rand from 15 seconds to #duration. The program interpreter complains that var #duration in this case is a string.

 

How can I convert it to number?

 

Thank you