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Functions

floating point operations in shell scripts

Terminal - floating point operations in shell scripts
echo $((3.0/5.0))
2009-09-03 16:35:09
User: andrew112358
Functions: echo
-8
floating point operations in shell scripts

Alternatives

There is 1 alternative - vote for the best!

Terminal - Alternatives
echo "scale=4; 3 / 5" | bc
2009-08-21 21:51:46
User: foob4r
Functions: echo
3

allows you to use floating point operations in shell scripts

bc -l <<< s(3/5)
2009-09-02 15:41:39
User: akg240
Functions: bc
3

-l auto-selects many more digits (but you can round/truncate in your head, right) plus it loads a few math functions like sin().

echo "5 k 3 5 / p" | dc
2009-09-03 00:21:54
User: xamaco
Functions: echo
1

using bc is for sissies. dc is much better :-D

Polish notation will rule the world...

wcalc -q <<< '3/5'
2010-07-07 20:31:21
User: smolav
1

Calculator for shell. Similar performance and basic usage as 'bc', but with more advanced features. Not installed on most systems by default.

exp="(2+3.0)/7.0*2^2"; val=$(awk "BEGIN {print $exp}" /dev/null)
2010-03-01 02:47:22
User: JeffChen
Functions: awk
0

a simple trick to do floating point operations in shell, use awk. You can evaluate any complicated expressions which can be evaluated in C.

Know a better way?

If you can do better, submit your command here.

What others think

What shell do you use?

in Bash 3.x this doesn't work:

echo $((3.0 / 5.0)) bash: 3.0 / 5.0: syntax error: invalid arithmetic operator (error token is ".0 / 5.0")
Comment by foob4r 254 weeks and 5 days ago

I tried it in zsh and it works, resulting in:

echo $((3.0/5.0))

0.59999999999999998

I'm sure there's a good reason why it doesn't return 0.6...

Comment by bwoodacre 254 weeks and 5 days ago

Your point of view

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