Commands using sort

Replace FILE with a filename (or - for stdin).

This command puts all the flags of the USE variable actually used by the packages you emerged to the file "use", and those which are unused but available to the file "notuse"

If you're like me and want to keep all your music rated, and you use xmms2, you might like this command.

I takes 10 random songs from your xmms2 library that don't have any rating, and adds them to your current playlist. You can then rate them in another xmms2 client that supports rating (I like kuechenstation).

I'm pretty sure there's a better way to do the grep ... | sed ... part, probably with awk, but I don't know awk, so I'd welcome any suggestions.

For users looking to simplify management of large entries in files and directories, this command is the key to fun and simplicity. Using the power sort, only a couple of seconds are necessary to accomplish what would take minutes or hours in ?standard? client applications.

It will return a ranked list of your most commonly-entered commands using your command history

This command will show the 20 processes using the most CPU time (hungriest at the bottom).

You can see the 20 most memory intensive processes (hungriest at the bottom) by running:

Or, run both:

Searches /var/log/secure for smtp connections then lists these by number of connections made and hosts.

Searches the /var/log/secure log file for Failed and/or invalid user log in attempts.

This command will tell you the 20 biggest directories starting from your working directory and skips directories on other filesystems. Useful for resolving disk space issues.

Here is a command line to run on your server if you think your server is under attack. It prints our a list of open connections to your server and sorts them by amount.

BSD Version:

Some commands (such as netcat) have a port option but how can you know which ports are unused?

Displays the duplicated lines in a file and their occuring frequency.

Low on disk space? Check the largest installed RPMs for delete canditates.

Can pipe to tail or change the awk for for file size, groups, users, etc.

This command is much quicker than the alternative of "sort | uniq -c | sort -n".

I use this to generate a playlist with all the podcasts I listen to.

Ordered from most recent to older.

The pipe to head removes the listing of . as the largest directory.

This command checks for the number of times when someone has tried to login to your server and failed. If there are a lot, then that user is being targeted on your system and you might want to make sure that user either has remote logins disabled, or has a strong password, or both. If your output has an "invalid" line, it is a summary of all logins from users that don't exist on your system.