There are four flavors. They use the same algorithm but have different input parameters. The result is four different hashes with four different output lengths. These four variants, SHA-3-224, SHA-3-256, SHA-3-384, and SHA-3-512, have outputs of 224, 256, 384, and 512 bits respectively. Although this may seem odd, it's the same situation as with the SHA-2 standard. There are four flavors of the SHA-2 algorithm, SHA-2-224, SHA-2-256, SHA-2-384, and SHA-2-512. For better or worse, we've been calling SHA-2-256 just "SHA-256" and SHA-2-512 "SHA-512".
You can see some sample SHA-3 test vectors (i.e. sample hashes) on the SHA-3 Wikipedia entry and at http://www.di-mgt.com.au/sha_testvector
My goal is to have a default "sha3deep" which computes hashes using the default length for forensics SHA-3 hashes, like this, assuming the standard was SHA-3-256:
$ sha3deep abc.txt
A secondary goal would be to have a way to generate SHA-3 hashes for the other flavors too. Here are some possible options for that:
Have a command line flag to indicate the flavor:
$ sha3deep -L 512 [FILES]
Having separate commands for each flavor:
$ sha3-512-deep [FILES]
What do you think should be the default bit-length for SHA-3 hashes? Which option would you prefer for computing the other flavors using the Hashdeep suite? Let me know by commenting below, tweeting at me, or sending an email to firstname.lastname@example.org.