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A command line calculator in Perl

Terminal - A command line calculator in Perl
perl -e 'for(@ARGV){s/x/*/g;s/v/sqrt /g;s/\^/**/g};print eval(join("",@ARGV)),$/;'
2009-12-21 21:03:27
User: JohnGH
Functions: perl
2
A command line calculator in Perl

Once I wrote a command line calculator program in C, then I found this... and added to it a bit.

For ease of use I normally use this in a tiny Perl program (which I call pc for 'Perl Calculator')

#!/usr/bin/perl -w

die "Usage: $0 MATHS\n" unless(@ARGV);for(@ARGV){s/x/*/g;s/v/sqrt /g;s/\^/**/g};

print eval(join('',@ARGV)),$/;

It handles square roots, power, modulus:

pc 1+2 (1 plus 2)

3

pc 3x4 (3 times 4)

12

pc 5^6 (5 to the power of 6)

15625

pc v 49 ( square root of 49 )

7

pc 12/3 (12 divided by 3)

4

pc 19%4 (19 modulus 4)

3

(you can string maths together too)

pc 10 x 10 x 10

1000

pc 10 + 10 + 10 / 2

25

pc 7 x v49

49

Alternatives

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Terminal - Alternatives

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What others think

Neat! zsh does some of this stuff also, which I was happy to learn recently, using double-parentheses $((1+1)) or single square brackets $[1+1]:

zsh-> print $((5**6)) zsh-> print $((5**0.5)) zsh-> print $[19 % 4]

also does bitwise shift >>, ++/-- in/decrementing

Comment by bwoodacre 225 weeks and 5 days ago

bashisms:

bc <<< 1+1 echo $((1+1))
Comment by rbossy 225 weeks and 4 days ago

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