"man zsh" gives you a list of zsh man pages. It's one of the best-documented packages I've seen so far; there is so much documentation that they had to split it up into about a dozen man pages.

If you know your way around bash, zsh should be easy enough to pick up - most of what you know from bash works exactly the same, but there's a ton of extra features.

You can carry them around just fine, as long as you protect them with a strong passphrase. General advice:

• use key-based authentication

• protect your key files with a strong passphrase

• once you have key-based access to a server, disable password-based access for your account (if you can)

• make it so that your passphrase is different from any password you use

• use a different key for each server, or group of servers

• use an ssh-agent to remember decrypted keys for you; this way, you only have to type the passphrase once per local session

As far as strong passphrases go, you need:

• a good cryptographic random number generator (/dev/random should do)

• a sufficiently long list of real words; combining lists from several languages is a good idea

Now pick four to six random words from those lists. Go with the first passphrase the RNG spits out.

This thing gets it almost right - I wouldn't trust an online password generator for this though.

You have a 100 word vocabulary?

Of course I exaggerate, and if you pick rare words, then it's not too bad. But, for example, that site provided:

camera outside final sink

If those common words are all in a 500 word list, you have 62,500,000,000 combinations. That's somewhere between the complexity of a 6 and 7 letter word that contains only uppercase letters, lowercase letters, and numbers.

But how do you know you'll misspell them the same way every time? Same with leet-speak.

It doesn't matter much whether the words are rare or not; as long as your lists are long enough, the entropy is going to be large, and the longer your lists, the smaller the chance for a common word randomly appearing.

4 words from a list of 2048 will give you 44 bits of entropy, and it's going to be easy to remember. With random characters, you can get roughly the same entropy using 9 characters from a set of 64. 'brain wide attack relationship', however, is much easier to remember than 'mgoaRUd6I'. Boost the entropy to 55, and you'll need 11 characters - 'soon garden pain musical car' is easy, 'jtGObH2JUz5' is not.

If you want even more entropy without using more words, add other languages to your list. Combine English, French, German and Spanish, 2048 words from each, and you'll get 176 bits of entropy for your four-word passphrase ('generalite hackfleisch gegenpol inanimate'). Even if you cut the entropy in half to account for overlapping and similar words between the languages, the random-character equivalent would still be an 18-character monstrosity such as '~j1Aaft3Wec~evkeo8'. Have fun with that.

If you pick only one, and don't do it randomly, then yes. Four random words out of 2048 are just as good as (or even slightly better than) 8 random characters out of 64.

But how often do you switch to a new password?

Don't know if you ever tried it, but Zorin Linux is pretty neat if you are more familiar with Windows, but want to try Linux. You can run most Windows programs under it...uses a mix between Wine and a Virtual Box virtual machine. You can create links to the Windows programs and run them just by clicking them. It's still Linux, so you have to know some stuff, but all in all...I think it's pretty good for those wanting to switch from Windows to Linux.

Suggestion for checking how safe a password is.
Every time someone changes their password, a server gets what would be stored in the database and runs a process to crack it. If it finds your password within a given time you have to pick a new password.

I think 50 commands is a bit much for a "most important" list.
~5 commands should be enough to be able to make use of it, when all you want to do is fix something in a configuration file on a random linux server...

xxd. Dumps files in various formats. You can get a hex editor style dump, and you can modify it and then "reassemble" it. You can also create headers from binary files with -i, which is perfect for Allegro 5's memfile addon.

valgrind's callgrind can also do some nice call graphs \o/

in fact, I highly recommend valgrind in general.