crumbtrail

GNU screen Wrapper for SSH Agent Forwarding

Thu, 15 Oct 2009 05:00:00 -0400

This problem is well-documented around the web, this is just my personal reminder. Others have crafted various solutions varying in complexity. I like this one for the simplicity and easy portability—I don’t remember who to credit for it, unfortunately.

Without getting too deeply into the gory details, if you connect to a remote shell and run GNU screen there, then detach the screen and come back to it in a later SSH session, environment variables that SSH agent forwarding requires to function will have changed and your screen session is none the wiser. This is rather annoying if you frequently connect to a gateway server and use screen to do work on other servers inside of it—your public key will not be forwarded to the internal servers on subsequent connections.

Enter wrapper script to save new SSH variables when you connect again and resume your screen session:

#!/bin/bash
# Wrapper script to set SSH env vars so agent forwarding works when
# resuming screen sessions. Place at ~/bin/screen and make sure
# your personal bin directory has priority in your PATH

for SSHVAR in SSH_CLIENT SSH_TTY SSH_AUTH_SOCK SSH_CONNECTION DISPLAY; do
    echo "export ${SSHVAR}=\"${!SSHVAR}\""
done > ~/.sshvars
/usr/bin/screen $*

Then, a simple alias for your .bashrc, to run once you’ve resumed screen:

# After reconnecting to a screen session, this restores env vars
# to allow agent forwarding to work again
alias fixssh='source ~/.sshvars'

Off you go to now to connect to those internal servers needing your forwarded key.

Sanely Rebuild Corrupt Font Caches on OS X

Thu, 08 Oct 2009 12:56:00 -0400

For Leopard, at least:

# Clear user font caches
$ atsutil databases -removeUser

# And system cache
$ sudo atsutil databases -remove

# Restart the ATS server
$ atsutil server -shutdown
ATSServer shutdown
$ atsutil server -ping
ATSServer is running

# Check for filesystem activity (this is just generally cool)
$ sudo fs_usage | grep ATS

You might possibly still need to restart applications, log out and back in, or restart completely. Thanks to the fine people on this thread.

"The future is no more uncertain than the present."

Sun, 05 Jul 2009 20:01:00 -0400

“The future is no more uncertain than the present.”

- Walt Whitman

"I’m no good at those “guess how many jelly beans are in the jar” things though...."

Tue, 02 Dec 2008 10:43:33 -0500

“I’m no good at those “guess how many jelly beans are in the jar” things though. Usually you just win the jar anyway, and who wants that many jelly beans?”

Gorefest

Thu, 06 Nov 2008 01:53:00 -0500

‘clean blood stain’ is probably one of those Web History moments where you want to make certain that you’re logged out of your Google account.

Um... Arrrr!!

Fri, 03 Oct 2008 12:39:00 -0400

Ches
I've switched Facebook to Pirate speak and it's pretty awesome

Sophie
You win! That's the most inane thing I've heard so far today

Get the Ruby mysql gem to build with MySQL installed from 64-bit binary installer: sudo env...

Mon, 23 Jun 2008 21:50:00 -0400

Get the Ruby mysql gem to build with MySQL installed from 64-bit binary installer:


sudo env ARCHFLAGS=”-Os -arch x86_64 -fno-common” \
gem install mysql -- --with-mysql-config=/usr/local/mysql/bin/mysql_config

Courtesy of synth @ Chris Cruft » Blog Archive » Ruby, Rails and MySQL with Leopard 10.5.2 and XCode 3.0

Sophie

Fri, 04 Apr 2008 15:57:24 -0400

Sophie
Do you know what I would have to do to make $65 an hour?

Ches
does it involve a pole and acrylic shoes?

Swap Control and Caps Lock in X.Org

Mon, 31 Mar 2008 03:54:14 -0400

In the keyboard section of xorg.conf:

Option "XkbOptions" "ctrl:swapcaps"

This will naturally effect all X users on a system, so you may want to look at alternatives if you’re not the only one using your system ;-)

Bash Prompt

Thu, 13 Mar 2008 01:45:00 -0400

export PS1="\n\[\033[0;32m\]\w\[\033[0m\]\n[\u@\h]\$ "

Produces a prompt that looks something like this, with that initial newline giving some space from the output of the previous command:

~/src/lexblog/lexcode
[ches@porco]$

Literature and Latte - Scrivener

Wed, 12 Mar 2008 02:39:52 -0400

Literature and Latte - Scrivener:

Scrivener is a word processor and project management tool created specifically for writers of long texts such as novels and research papers. Has a screenplay mode, WriteRoom-like fullscreen edit,…

gitnub

Wed, 12 Mar 2008 02:39:52 -0400

gitnub:

A RubyCocoa frontend to the Git SCM.

finding that just about everything in the Rails Recipes book is useful and pertinent

Wed, 12 Mar 2008 01:39:15 -0400

finding that just about everything in the Rails Recipes book is useful and pertinent

"It does not matter how slow you go so long as you do not stop."

Wed, 12 Mar 2008 01:06:53 -0400

“It does not matter how slow you go so long as you do not stop.”

- Wisdom of Confucius