Multiplication on command line terminal

Question

I\'m using a serial terminal to provide input into our lab experiment. I found that using

$ echo \"5X5\"

just returns a string of \"

Answer 1

A simple shell function (no sed needed) should do the trick of interpreting '5X5'

$ function calc { bc -l <<< ${@//[xX]/*}; };
$ calc 5X5
25
$ calc 5x5
25
$ calc '5*5'
25