This enables me to be yet more lazy.

[nonethefewer]

To do basic calculations on the command line in *nix/*nux:

echo 2+2 | bc

Or just type bc, and go from there.

http://linux.die.net/man/1/bc

Comments

[modularformsboy.livejournal.com]

or:

echo $((2 + 2))

or:

echo 2 2 + p | dc

[the-xtina.livejournal.com]

Huh, cool.  The latter I can follow; how does the former go?  Why does that go?

[hitchhiker.livejournal.com]

bash syntax for "evaluate this as an arithmetic expression" (http://tldp.org/HOWTO/Bash-Prog-Intro-HOWTO-10.html#ss10.2).