Sometimes, you don't really care about all the other information that ifconfig spits at you (however useful it may otherwise be). You just want an IP. This strips out all the crap and gives you exactly what you want.

Yeah I know it's been up here a million times, but this service is a really clean and nice one. Nothing but your IP address on it. Actually I was to write something like this, and noticed this on appspot... ;)

Use the hold space to preserve lines until data is needed.

I often need to extract a function from a bash script and this command will do it.

In this simple example the command will add a comma to the end of every line except the last. I found this really useful when programatically constructing sql scripts. See sample output for example.

Using column to format a directory listing

This will comment out a line, specified by line number, in a given file.

I needed a way to search all files in a web directory that contained a certain string, and replace that string with another string. In the example, I am searching for "askapache" and replacing that string with "htaccess". I wanted this to happen as a cron job, and it was important that this happened as fast as possible while at the same time not hogging the CPU since the machine is a server.

So this script uses the nice command to run the sh shell with the command, which makes the whole thing run with priority 19, meaning it won't hog CPU processing. And the -P5 option to the xargs command means it will run 5 separate grep and sed processes simultaneously, so this is much much faster than running a single grep or sed. You may want to do -P0 which is unlimited if you aren't worried about too many processes or if you don't have to deal with process killers in the bg.

Also, the -m1 command to grep means stop grepping this file for matches after the first match, which also saves time.

Uses curl to download page of membership of US Congress. Use sed to strip HTML then perl to print a line starting with two tabs (a line with a representative)

Assuming that $script contains the filename of a script you'd like to post as part of a comment on this site, this will prefix each line with '$' and pipe it into the X selection. From there just put the cursor in the right place in the comments box and middle-click.

Should work pretty much anywhere with xclip installed. On debian-ish systems this is installed as part of the package "xclip".

Checks the Gmail ATOM feed for your account, parses it and outputs a list of unread messages.

For some reason sed gets stuck on OS X, so here's a Perl version for the Mac:

If you want to see the name of the last person, who added a message to the conversation, change the greediness of the operators like this:

Manages everything through one sed script instead of pipes of greps and awks. Quoting of shell variables is generally easier within a sed script.

Based on the MrMerry one, just add some visuals to differentiate files and directories

Based on the MrMerry one, just add some visuals and sort directory and files

saves one command. Needs GNU grep though :-(

The grep switches eliminate the need for awk and sed. Modifying vim with -p will show all files in separate tabs, -o in separate vim windows. Just wish it didn't hose my terminal once I exit vim!!

This will drop you into vim to edit all files that contain your grep string.