Generating a SHA-256 hash from the Linux command line

Question

I know the string \"foobar\" generates the SHA-256 hash c3ab8ff13720e8ad9047dd39466b3c8974e592c2fa383d4a3960714caef0c4f2 using http://hash.online-convert.com/sh

Answer 1

If the command sha256sum is not available (on Mac OS X v10.9 (Mavericks) for example), you can use:

echo -n "foobar" | shasum -a 256