REQUEST - bash floating point math support

[Zachary Santer]

On Tue, Jun 4, 2024 at 4:01 PM Saint Michael <venefax@gmail.com> wrote:
>
> >
> > It's time to add floating point variables and math to bash.
>
> It just makes so much easier to solve business problems without external
> calls to bc or Python.
> Please let's overcome the "shell complex". Let's treat bash a real language.

You want to expound on use cases?

I've seen one, for myself: writing a script to bind keyboard shortcuts
to, so I could change the level of screen magnification in GNOME by
increments of less than 100%. The magnification factor is handled as a
fractional number - 1.5, 1.75, etc. So, to change the magnification
factor by increments of 0.25 or 0.5, I had to print an expression into
bc in a command substitution.

The math that people want to do in bash is going to be integer the
vast majority of the time, though, and scripts are of course written
to expect integer math.

Bash could potentially detect floating point literals within
arithmetic expansions and adjust the operations to use floating point
math in that case. I believe C treats a literal 10 as an integer and a
literal 10.0 as a floating point number, for instance, so this
wouldn't really be going against the grain.

For completeness, a floating point variable attribute could
potentially be added. 'declare -i var' will cause var to be treated as
an integer, though var can be referenced within an arithmetic
expansion without this attribute. declare -f and -r (real, anybody?)
are already taken for other things, so I'm not sure what the natural
choice of option would be.

Zack