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Creates PodFeeds.txt, a file that lists the URLs of rhythmbox podcasts from the rhythmdb.xml file.
The first grep any line with pod-feed in it plus the following five lines. The second grep throws out any line not containing . sed removes the leading four spaces then and the trailing . Using a colon as sed's separating character avoids having to escape the /. Works ok with Mythbuntu 9.04 (used mostly as a three line bash script).

Read and write to TCP or UDP sockets with common bash tools
Ever needed to test firewalls but didn't have netcat, telnet or even FTP? Enter /dev/tcp, your new best friend. /dev/tcp/(hostname)/(port) is a bash builtin that bash can use to open connections to TCP and UDP ports. This one-liner opens a connection on a port to a server and lets you read and write to it from the terminal. How it works: First, exec sets up a redirect for /dev/tcp/$server/$port to file descriptor 5. Then, as per some excellent feedback from @flatcap, we launch a redirect from file descriptor 5 to STDOUT and send that to the background (which is what causes the PID to be printed when the commands are run), and then redirect STDIN to file descriptor 5 with the second cat. Finally, when the second cat dies (the connection is closed), we clean up the file descriptor with 'exec 5>&-'. It can be used to test FTP, HTTP, NTP, or can connect to netcat listening on a port (makes for a simple chat client!) Replace /tcp/ with /udp/ to use UDP instead.

Create an alias, store it in ~/.bash_aliases and source your new alias into the ~/.bashrc
This is useful if you use a shell with a lot of other users. You will be able to run "topu" to see your running processes instead of the complete 'top -u username'. Read more on alias: http://man.cx/alias

Counting the source code's line numbers C/C++ Java
Count your source and header file's line numbers. This ignores blank lines, C++ style comments, single line C style comments. This will not ignore blank lines with tabs or multiline C style comments.

Find total Terabytes written to a SSD
You must have smartmontools installed for this to work. This also assumes you 512 byte sector sizes, this is pretty standard.

Clean the /boot directory
On Fedora clean the boot directory; erase older kernel

Get the dir listing of an executable without knowing its location

Recompress all files in current directory from gzip to bzip2
Find all .gz files and recompress them to bz2 on the fly. No temp files. edit: forgot the double quotes! jeez!

Colorizes an access log
Puts a splash of color in your access logs. IP addresses are gray, 200 and 304 are green, all 4xx errors are red. Works well with e.g. "colorize access_log | less -R" if you want to see your colors while paging. Use as inspiration for other things you might be tailing, like syslog or vmstat Usage: $ tail -f access.log | colorize

Sort disk usage from directories
Sort disk usage from directories in the current directory


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