[BASH] Regex for floating point number

Shell Programming and Scripting
1

Hey again,

I have a basic regex that tests if a number is a float.

Thank you.

2 
sed -n '/^-*[0-9]*[.]*[0-9]*$/p' myFile
3

Thanks for the reply.

Sadly that regex allows for multiple minus signs and multiple decimal points.

For example:

------------------9......................3

Is valid with that regex.

Thanks anyway, though.

4

It doesn't take much of a change:

$ sed -En '/^-?[0-9]*[.]?[0-9]+$/p' file
-10.4
1.0

(if your sed doesn't support extended regular expressions, grep surely will grep -E '^-?[0-9]*[.]?[0-9]+$' file )

5

I prefer to use the shell rather than an external command.

This is a beginning (I'm not at my computer right now so I don't have the full function):

is_fpnum()
{
  case $1 in
    *[!-0-9]* | *.*.* | -*-* ) ## add invalid patterns as needed
             return 1;;
  esac
}
6

Disregard the last post I made, I had a stupid error in it. All working now.

Thank you, all.