'Sometimes, while working on the command line (especially when dealing with a shell script), you may find yourself in a situation where you have to perform actions like searching for a substring in a string, finding its index, as well as other things like performing comparisons and arithmetic operations. For those who aren't in the know, there exists a command line utility - dubbed expr - that lets you do all this. In this tutorial, we will discuss the basics of this command along with some of the features it provides.' -- source: https://www.howtoforge.com/linux-expr-command/ Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, NZ +64 (7) 858-5174 http://www.cms.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/