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Quick command line math

Terminal - Quick command line math
expr 512 \* 7
2009-09-23 19:11:38
User: chuckr
Functions: expr
4
Quick command line math

expr will give you a quick way to do basic math from the CLI. Make sure you escape things like * and leave a space between operators and digits.

Know a better way?

If you can do better, submit your command here.

What others think

Doesn't do decimals. Try this Perl command.

perl -le 'print 51.2 * 2'

Comment by billbose 361 weeks and 1 day ago

bc does floating point, large powers and trig functions too

bc

3584

bc -l

73.14285714285714285714

bc

9223372036854775808

Comment by Escher 361 weeks and 1 day ago

the comment above came out wrong

bc <<< 512*7

3584

bc -l <<< 512/7

73.14285714285714285714

bc <<< 512^7

9223372036854775808

Comment by Escher 361 weeks and 1 day ago

if you don't care about decimals then try

echo $((512*7))

you don't need to care about spaces nor escaping anything

Comment by edo 361 weeks ago

All good solutions too. But the original wins for fewest number of keystrokes :-)

Also, the bc example above seems wrong.

echo "512*7" | bc

will work.

Comment by chuckr 361 weeks ago

the bc examples use bash 'here string' operator, it won't work in other shells, but in bash it's the fewest keystrokes, and more versatile.

Comment by Escher 361 weeks ago
bc <<< 512*7

is 12 keystrokes

expr 512 \* 7

is 13 keystrokes

Comment by Escher 361 weeks ago

and in fact, it could just be

bc<<<512*7

which is 10 keystrokes.

Comment by Escher 361 weeks ago

OK. I wasn't using bash when trying the '

Comment by chuckr 361 weeks ago

OK. I wasn't using bash when trying the 'here string' solution so I didn't count its keystrokes. Good solution, if using bash.

Comment by chuckr 361 weeks ago

Your point of view

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