[Help-bash] floating point arithmetic

[Jerry]

I was told that "bash" does not support floating point arithmetic. I was
wondering if there are any plans to change that in future releases?

Thanks!

[John McKown]

Post by Jerry
I was told that "bash" does not support floating point arithmetic. I was
wondering if there are any plans to change that in future releases?

​Gee, I never knew that. My work around would be something like:

$ x=1.1
$ echo $x
1.1
$ y=2.2
$ echo $y
2.2
$ z=$(echo "${x} + ${y}" | bc)
$ echo $z
3.3
​

Post by Jerry
Thanks!
--
Jerry

[Greg Wooledge]

Post by Jerry
I was told that "bash" does not support floating point arithmetic. I was
wondering if there are any plans to change that in future releases?

See also <http://mywiki.wooledge.org/BashFAQ/022>

[John McKown]

Post by Greg Wooledge

Post by Jerry
I was told that "bash" does not support floating point arithmetic. I

was

Post by Jerry
wondering if there are any plans to change that in future releases?

See also <http://mywiki.wooledge.org/BashFAQ/022>
​Very nice!​

[Barry Walker]

Hi Jerry...

Post by Jerry
I was told that "bash" does not support floating point arithmetic. I was
wondering if there are any plans to change that in future releases?

If you are running CygWin then bc and dc are NOT part of a default install.
However all *NIX type systems have awk which can do floating point along with
some mathematical functions...

man awk:

https://www.freebsd.org/cgi/man.cgi?query=awk&sektion=1

[João Eiras]

I have my own little bash script for this use case:

$ cat calc
IFS=""
awk "BEGIN { print (${*:-0}); }" /dev/null

$ calc "2.3-5.4"

Post by Barry Walker
Hi Jerry...

Post by Jerry
I was told that "bash" does not support floating point arithmetic. I was
wondering if there are any plans to change that in future releases?

If you are running CygWin then bc and dc are NOT part of a default install.
However all *NIX type systems have awk which can do floating point along with
some mathematical functions...
https://www.freebsd.org/cgi/man.cgi?query=awk&sektion=1
--
73...
Bazza, G0LCU...
Team AMIGA...
The less that I speak, the smarter I sound.

[Jerry]

Thanks to everyone who replied. I appreciate it. However, I am still wondering
if Bash will ever support true floating point arithmetic natively? I was
advised to switch to "ksh93"; however, I have been trying hard to learn bash,
and I really don't want to switch if not absolutely necessary.

Thanks again, I got some good pointers.

[Chet Ramey]

Post by Jerry
Thanks to everyone who replied. I appreciate it. However, I am still wondering
if Bash will ever support true floating point arithmetic natively? I was
advised to switch to "ksh93"; however, I have been trying hard to learn bash,
and I really don't want to switch if not absolutely necessary.

I don't think the class of problems that native floating point arithmetic
would solve (as opposed to using something like awk/bc/dc) is large
enough to compensate for the development effort. If someone else wanted
to take a crack at it, though, I'd most likely incorporate the results.

[Chris F.A. Johnson]

Post by João Eiras
$ cat calc
IFS=""
awk "BEGIN { print (${*:-0}); }" /dev/null

I use this:

calc()
{
awk 'BEGIN {print '"${*//x/*}"'}'
}

...so that I can use 'x' instead of '*', which needs quoting.