du -m option to not go across mounts (you usually want to run that command to find what to destroy in that partition)

-a option to also list . files

-k to display in kilobytes

sort -n to sort in numerical order, biggest files last

tail -10 to only display biggest 10

reverse the sorting of ls to get the newest file:

Problems:

If there are no files in the directory you will get a directory or nothing.

Takes IP from web logs and pipes to iptables, use grep to white list IPs.. use if a particular file is getting requested by many different addresses.

Sure, its already down pipe and you bandwidth may suffer but that isnt the concern. This one liner saved me from all the traffic hitting the server a second time, reconfigure your system so your system will work like blog-post-1.php or the similar so legitimate users can continue working while the botnet kills itself.

Should be a bit more portable since echo -e/n and date's -Ins are not.

This is useful when watching a log file that does not contain timestamps itself.

If the file already has content when starting the command, the first lines will have the "wrong" timestamp when the command was started and not when the lines were originally written.

Your version works fine except for someone who's interested in commands 'sudo' was prefixed to

i.e. in your command, use of sudo appears as number of times sudo was used.

Slight variation in my command peeks into what commands sudo was used for and counts the command

(ignores 'sudo')

Information for only one core.

This combines the above two command into one. Note that you can leave off the last two commands and simply run the command as

"find /home/ -type f -exec du {} \; 2>/dev/null | sort -n | tail -n 10"

The last two commands above just convert the output into human readable format.

Often you need to find the files that are taking up the most disk space in order to free up space asap. This script can be run on the enitre filesystem as root or on a home directory to find the largest files.

this adds a random color to your prompt and the external ip.

useful if you are using multiple mashines with the same hostname.

The given example collects output of the tail command: Whenever a line is emitted, further lines are collected, until no more output comes for one second. This group of lines is then sent as notification to the user.

You can test the example with

Tail curren postfix maillog.

tail -c 1 "$1" returns the last byte in the file.

Command substitution deletes any trailing newlines, so if the file ended in a newline $(tail -c 1 "$1") is now empty, and the -z test succeeds.

However, $a will also be empty for an empty file, so we add -s "$1" to check that the file has a size greater than zero.

Finally, -f "$1" checks that the file is a regular file -- not a directory or a socket, etc.

You can use this one-liner for a quick and dirty (more customizable) alternative to the watch command. The keys to making this work: everything exists in an infinite loop; the loop starts with a clear; the loop ends with a sleep. Enter whatever you'd like to keep an eye on in the middle.

Download colorizer by @raszi @ http://github.com/raszi/colorize

git log --format=%H | tail -1 doesn't work anymore

'data' is the directory to backup, 'backup' is directory to store snapshots.

Backup files on a regular basis using hard links. Very efficient, quick. Backup data is directly available.

Same as explained here :

http://blog.interlinked.org/tutorials/rsync_time_machine.html

in one line.

Using du to check the size of your backups, the first backup counts for all the space, and other backups only files that have changed.

Tail all logs that are opened by all java processes. This is helpful when you are on a new environment and you do not know where the logs are located. Instead of java you can put any process name. This command does work only for Linux.

The list of all log files opened by java process:

Can anyone make a shorter one?

This doesn't work: