Computing addition, subtraction, multiplication, division in linux scripts

Computing, subtraction, multiplication, division, linux general technology-Linux programming and kernel information in a Linux script. The following is a detailed description. In linux, the addition, subtraction, multiplication, division, is actually a small program named "expr ". This program is very easy to use, but it should be noted that do not forget to use space and escape. For example, to calculate the multiplication of two numbers, you should write it like this:

Expr 1024 \ * 1024

In fact, it is quite simple. I have a good reference document here. This program can not only calculate addition, subtraction, multiplication, division, but also many expressions that can calculate the results.

Expr command: http://study.chyangwa.com/IT/AIX/aixcmds2/expr.htm