Sorry, that was overly snarky and that wasn't warranted.
Are you talking about how you store your own passwords so that you may retrieve them in order to log into some service, or are you talking about how you store user credentials as part of an application?
If you're storing your own passwords, just use a well-rated password locker program, or store them in a TrueCrypt volume or similar. If you're storing your users' passwords... well, don't -- store the hash like that Atwood article suggests.
To your initial question, if you need to use the output of one program as an argument to another program, you can wrap it in backticks:
no, I am just storing my passwords in a text file and I don't want to do it plaintext, but I also don't want to have to encode the whole text file and have to decode it first to use it. Just make it more complicated if someone opens it.
Thanks for the reminder of ticks (`) I was accidentally using single quotes (')
Ah, then I stand by my original advice. Keep in mind, base64 encoded ascii/UTF-8/whatever encoding you like is still plaintext. If you want to be secure, use a password locker program or store them in a text file inside of a small encrypted volume which you unmount as soon as you're done with it (TrueCrypt is nice for this).
But if you don't care about them actually being secure, party on...
Aside from backticks, you can also use the dollar quote (I'm sure this has a better name):
$(some_command some arguments | some_other_command)
Finally, back to the original "how do I combine this with md5" question, you don't, as that won't do what you want. That is, you want to be able to recover the plaintext, but cryptographic hashes are designed specifically to make that practically impossible.
Are you talking about how you store your own passwords so that you may retrieve them in order to log into some service, or are you talking about how you store user credentials as part of an application?
If you're storing your own passwords, just use a well-rated password locker program, or store them in a TrueCrypt volume or similar. If you're storing your users' passwords... well, don't -- store the hash like that Atwood article suggests.
To your initial question, if you need to use the output of one program as an argument to another program, you can wrap it in backticks:
But really there's no benefit to converting it to base64 before you hash.