*nix Tip of the Day: tee

Posted Thu 15 May 2008 18:58 under category tips

tee is a handy little utility that probably all of you know about, but I just found this year. Consider the following scenario: you're maintaining your Gentoo Linux system and you need to add a line to /etc/portage/package.unmask. So you type

sudo echo "sys-kernel/gentoo-sources" >> /etc/portage/package.unmask

right? Nope! The way shell parsing works, that turns into

(sudo echo "sys-kernel/gentoo-sources") >> /etc/portage/package.unmask

which is most certainly not what you want, since you probably don't have permissions to /etc/portage/package.unmask. The solution is the tee utility. It would be ...

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*nix Tip of the Day: rxvt-unicode and terminfo

Posted Wed 14 May 2008 10:03 under category tips

An important part of a *nix system is a good terminal emulator. For some, this means the classic xterm. The same xterm that's happy to use 7 MiB of resident memory for each instance. Or perhaps you run a full DE like Gnome and are happy to use gnome-terminal and enjoy 19 MiB of resident. Personally, I use rxvt-unicode (urxvt). It's a very lightweight version of rxvt which has neato features like full Unicode support and a daemon mode that lets you pool multiple instances. For example, my urxvtd processs is using 41 MiB of resident, but hosting ...

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*nix Tip of the Day: SSH SOCKS Proxying

Posted Tue 13 May 2008 16:00 under category tips

Continuing on my theme of SSH tips, today's Tip of the Day talks about the awesomeness of SOCKS proxying. As some of the more savvy among you may know, OpenSSH supports full Layer-2/Layer-3 VPN functionality using a tun device. This is an incredibly useful feature if you're off-site and need like-local access to home, work, school, or somesuch. But it requires root access, and is more than a little bit of a pita to set up. If all you need is access to things like the web, e-mail, and instant messaging, there's an easier way.

SOCKS ...

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*nix Tip of the Day: SSH Agent Forwarding

Posted Mon 12 May 2008 18:31 under category tips

Today's *nix tip of the day involves SSH and the magic that is Agent Forwarding.

SSH, as some of you know, is a handy way to connect to *nix systems in an untrusted environment. Its primary use is to allow one to remotely access a remote system and get a shell, securely. Basically, encrypted telnet. Of course, SSH has tons of other useful features (like tunneling, proxying, and multiplexing), some of which might come up in future Tips of the Day.

One of SSH's greatest features is its public/private key system. Basically, using private keys, you can ...

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*nix Tip of the Day: SSH Private/Public Keys

Posted Sun 11 May 2008 18:00 under category tips

Hello kind readers, and welcome to by *nix Tip of the Day. It's finals week, and I'm sort of slacking, so I thought I'd post some of my accumulated folk wisdom on the Internet, so that it might help others.

Today's topic is SSH Private/Public Keys. If any of you are CS majors, or go to a tech-heavy school, or generally interact with Linux/OS X/Solaris/HP-UX/AIX/any other *nix, you've probably used SSH. SSH, at its most basic, is a replacement for telnet and rlogin; it allows you to get a ...

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