allows simple C shell access to the power of bc - never could figure out how to do the same thing with Bash - that's why I use tcsh most of the time.

Compares two versions with dpkg. It is not always obvious what version dpkg/apt will consider to be more recent. Operators include the following :

* These treat an empty version as earlier than any version: lt le eq ne ge gt.

* These treat an empty version as later than any version: lt-nl le-nl ge-nl gt-nl.

* These are provided only for compatibility with control file syntax: < > >.

This command doesn't output anything. It only returns with status 0 or 1, hence the echo "y" || echo "n" to get an output.

This command kills all processes with 'SomeCommand' in the process name. There are other more elegant ways to extract the process names from ps but they are hard to remember and not portable across platforms. Use this command with caution as you could accidentally kill other matching processes!

xargs is particularly handy in this case because it makes it easy to feed the process IDs to kill and it also ensures that you don't try to feed too many PIDs to kill at once and overflow the command-line buffer.

Note that if you are attempting to kill many thousands of runaway processes at once you should use 'kill -9'. Otherwise the system will try to bring each process into memory before killing it and you could run out of memory. Typically when you want to kill many processes at once it is because you are already in a low memory situation so if you don't 'kill -9' you will make things worse

These part of the command:

svn status | grep '^\?' => find new file or directory on working copy

sed -e 's/^\?//g' => remove "^" character on the first character of file name

xargs svn add => add file to subversion repository

You can modify above command to other circumtances, like revert addition files or commit files that have been modified. ^_^

Live extension of an ext3 file system on logical volume $v by 200GB without the need to unmount/remount.

Requires that you have 1) a version of resize2fs that contains code merged from ext2online, and 2) kernel support for online resizing. (e.g. RHEL 5)

Kills the most recently created firefox process.

Output: Version 3.2-0 (for example if you type # aptitude show bash | grep Vers

Depends on the language of your distribution, because the name of the word "Version" in other languages may be different.

This will create an exact duplicate image of your hard drive that you can then restore by simply reversing the "if" & "of" locations.

Alternatively, you can use an SSH connection to do your backups:

rsyncs files to a server excluding listed files

also a file can be used to exclude common exclude rules and/or to exclude a ton of files, like so:

where exclude.txt has one rule per line:

*.mp3

*.svn*

On the Mac, the format ifconfig puts out is little different from Linux: the IP address is space separated, instead of colon. That makes parsing the IP address easier. See releated command for Linux/Unix:

http://www.commandlinefu.com/commands/view/651/getting-the-ip-address-of-eth0

a quick one-line way to disable caps lock while running X.

Edit the files, each in a separate tab. use gT and gt to move to the left- and right-tab, respectively. to add another tab while editing, type ':tabe filename'

This command will list a CSV list of infected files detected by clamav through squidclamav redirector.

Parses tektronic given csv files for both channel 1 and channel 2 and joins them together. Can be easily used by gnuplot after that.

Replace 'more' command with any command which is in your PATH.

It's pretty common to forgot to commit a files, be it a modification, or a brand new file.

If you did forget something, git add the files you want, and then git commit --amend. It will essentially redo the last commit, with the changes you just added. It seeds the commit message with the last commit message by default.

You probably shouldn't do this if you've already pushed the commit.