square root of number using sqrt and/or awk
 

Hi all,

I'm trying to get the square root of a number and have used a couple of methods but neither has worked for me.

First method:


Second method:


I have read somewhere that I must include <math.h> but am not exactly sure of what this is referring to and haven't seen this in any of the example scripts I have looked at. I am trying to write this using korn shell. Any help would be greatly appreciated.

How about:

echo sqrt "($number)" | bc

thanks heaps mate!

you need BEGIN in you awk script since there's no file input
next time when it doesn't work, don't just say it doesn't work. Describe any errors or strange phenomena clearly.

The math.h thing is for when you are writing a program in C. If you are using shell script, you will need to use some external program, as most shells do not include a built-in square root command.

bc is probably the best bet here as it is a very small program (so it is quicker to invoke than other programs), and it can give you a lot of precision, or as little as you want.

bc reads from standard input, so you can echo an expression to evaluate like these examples: