Unix Notes

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Prevent a given partition from mounting at boot

12/25/2009 in Unix Notes by face | No comments

There are several hints on this site for unmounting a partition at login, but a better way to make this happen can be used. You need to create an entry point in your filesystem table to tell the OS not to mount that specific volume, and this is relatively easy. In Mac OS X, and under Linux and others unix systems, the volume mounting configuration file is located in /etc/fstab. This file in Mac OS X Tiger is empty in Panther, its commented, but type man fstab in Terminal to read some important information.

via Prevent a given partition from mounting at boot – Mac OS X Hints.

List functions defined in shell

4/23/2009 in Unix Notes by face | No comments

I defined a function in bash. I forgot what it was, specifically. I wanted to see all of the functions.

declare -f - functions+body
declare -F - functions

clone media

4/20/2009 in Unix Notes by face | No comments

sudo rsync –dry-run –verbose –archive “/Volumes/black-hole/Clones/” “/Volumes/Media”

Terminal Tips: Enable path view in Finder

12/6/2008 in System Software Notes, Unix Notes by face | No comments

Terminal Tips: Enable “path view” in Finder:

defaults write com.apple.finder _FXShowPosixPathInTitle -bool YES

(Via The Unofficial Apple Weblog.)

Receive syslog log info from router on iMac (Leopard)

8/12/2008 in System Software Notes, Unix Notes by face | 1 comment

THIS DOESN’T WORK. Logs get confused (logging stops). Haven’t figured out a way to make it *really* work on Leopard.

Receive syslog info from router on iMac (Leopard)
Posted: Nov 28, 2007 6:51 AM in response to: YamaLuha
Solved

To enable your Leopard system to receive network syslog submissions edit /System/Library/LaunchDaemons/com.apple.syslogd.plist and uncomment the lines specified in the comments so that the end of the file looks something like this.

<key>NetworkListener</key>
<dict>
  <key>SockServiceName</key>
  <string>syslog</string>
  <key>SockType</key>
  <string>dgram</string>
</dict>

NB – the NetworkListener is part of the Socket dict entry!!!

Then execute the following commands (wait a few seconds between commands):
sudo launchctl unload /System/Library/LaunchDaemons/com.apple.syslogd.plist
sudo launchctl load /System/Library/LaunchDaemons/com.apple.syslogd.plist

That is enough to get an apple base station to dump it’s log into the system log.

Sed – An Introduction and Tutorial

8/5/2008 in Unix Notes, Utilities Notes by face | 2 comments

Sed is the ultimate stream editor. If that sounds strange, picture a stream flowing through a pipe. Okay, you can't see a stream if it's inside a pipe. That's what I get for attempting a flowing analogy. You want literature, read James Joyce.

Anyhow, sed is a marvelous utility. Unfortunately, most people never learn its real power. The language is very simple, but the documentation is terrible. The Solaris on-line manual pages for sed are five pages long, and two of those pages describe the 34 different errors you can get. A program that spends as much space documenting the errors than it does documenting the language has a serious learning curve.

Do not fret! It is not your fault you don't understand sed. I will cover sed completely. But I will describe the features in the order that I learned them. I didn't learn everything at once. You don't need to either.

Sed – An Introduction and Tutorial.

howto/ccache – MacPorts – Trac

6/6/2008 in Unix Notes, Utilities Notes by face | No comments

howto/ccache – MacPorts – Trac

This HOWTO covers how to enable building with ccache. It is a compiler cache. It uses the gcc -E switch and a hash to detect when a compilation can be satisfied from cache. The effect is that packages frequently compile 5-10 times faster than they would otherwise.

We’ll see how this changes behavior – installed 2008-06-06 05:00:00

Making ipfw make them go away

5/27/2008 in System Software Notes, Unix Notes, Web Serving by face

sudo ipfw add deny src-ip 123.45.67.89, 127.0.0.1/8

That should do the trick.

Time Machine full system restore

2/21/2008 in System Software Notes, Unix Notes by face | 2 comments

Well, I hosed my printing system. At least it appeared that way.

I know – let’s go backwards in time and make like it didn’t happen.

Boot from the Leopard DVD. Tell it we want to restore from a Time Machine backup.
Wait about 90 minutes for the whole thing to restore. So far, so good.

I got the printing working as desired. All the systems can see the shared printers.
That should do it, right? Wrong!

1. I have a leftover swap file on the Time Machine disk – easy to get rid of – delete it.
2. I have a *very* large backup snapshot in the Time Machine – like 55GB – like it is a complete snap of the restored system. You would think that it would know that I restored from snapshot “A” and would simply make a hard link to that…hmmm
3. mail doesn’t work. My nightly cron job that backs up the databases sends mail. I didn’t get it.

Have to fix mail – wound up trying sudo /etc/postfix/post-install create-missing which got me most of the way there. I had to restart to get the mail daemons all “happy” again.

Oh, yes.

iTunes lost window positioning, had to be re-authorized for iTunes Store songs.

Mail.app decided that it had to import all of my mail! Only real problem there was that it had lots of messages marked unread that had actually been read. Not a big deal. It got the 66,000+ messages into the right places.

Leopard and crontabs

12/23/2007 in System Software Notes, Unix Notes by face | No comments


macosxhints.com – 10.5: Migrate crontabs from 10.4

n Mac OS X 10.4 (and earlier?), crontabs (the lists of tasks scheduled with cron) were stored in /var/cron/tabs. However, in 10.5, they are now stored in /usr/lib/cron/tabs, and the installer doesn’t seem to move any existing files from the old to the new location. So, the easy way to bring your old crontabs across is to run the following command in a Terminal:
sudo mv /var/cron/tabs/* /usr/lib/cron/tabs
Note that this command will replace any crontabs you’ve edited or set up since upgrading to Leopard with the version you had in Tiger; if you think there’s likely to be a clash, it would be a good idea to open the old files in a text editor and copy-and-paste the entries across to your new crontab (using crontab -e) instead.

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