This will create the file /tmp/pkgdetails, which will contain a listing of all the files installed on your RPM-based system (RedHat, Fedora, CentOS, etc). Useful should the RPM system/database become corrupted to find which package installed which files.

Note, the [remotePort] should be opened in the firewall first. First, start the destination box listening, then fire off the sending box. Data from the /dev/zero device in memory of the source machine is read out using dd, sent over the network with nc, and read back in from the other side of the network with nc, going to the /dev/null device. Essentially, it is a memory-network-memory copy operation, the output of dd will tell you how fast your network really is performing.

In Debian based distros, this command will list 'binutils' package details which contains 'nm' command. You can replace 'nm' to any other command.

Depending on the speed of you system, amount of RAM, and amount of free disk space, you can find out practically how fast your disks really are. When it completes, take the number of MB copied, and divide by the line showing the "real" number of seconds. In the sample output, the cached value shows a write speed of 178MB/s, which is unrealistic, while the calculated value using the output and the number of seconds shows it to be more like 35MB/s, which is feasible.

Scan for open ports on the target device/computer (192.168.0.10) while setting up a decoy address (192.168.0.2). This will show the decoy ip address instead of your ip in targets security logs. Decoy address needs to be alive. Check the targets security log at /var/log/secure to make sure it worked.

ps command gives the possibility to display information with custom formatting with the -o options followed by the format specifier list.

Redirects the contents of your clipboard through a pipe, to a remote machine via SSH.

Using 7z to create archives is OK, but when you use tar, you preserve all file-specific information such as ownership, perms, etc. If that's important to you, this is a better way to do it.

greps using only ascii, skipping the overhead of matching UTF chars.

Some stats:

$ export LANG=C; time grep -c Quit /var/log/mysqld.log

7432

real 0m0.191s

user 0m0.112s

sys 0m0.079s

$ export LANG=en_US.UTF-8; time grep -c Quit /var/log/mysqld.log

7432

real 0m13.462s

user 0m9.485s

sys 0m3.977s

Try strace-ing grep with and without LANG=C

I've used technicalpickles command a lot, but this one handles whitespaces in filenames. I'm sure you want to create an alias for it :)

Just a handy way to get all the unique links from inside all the html files inside a directory. Can be handy on scripts etc.

Handy when you need to create a list of files to be updated when subversion is not available on the remote host. You can take this tar file, and upload and extract it where you need it. Replace M and N with the revisions specific to yours. Make sure you do this from an updated (svn up) working directory.

This one would be much faster, as it's only one executed command.

awk can clear the screen while displaying output. This is a handy way of seeing how many lines a tail -f has hit or see how many files find has found. On solaris, you may have to use 'nawk' and your machine needs 'tput'

Simple but useful little command to unzip all files in a directory.

Save the script as: sort_file

Usage: sort_file < sort_me.csv > out_file.csv

This script was originally posted by Admiral Beotch in LinuxQuestions.org on the Linux-Software forum.

I modified this script to make it more portable.

- for .xsession use -

Advantages of running a urxvt daemon include faster creation time for terminal windows and a lot of saved memory.

You can start new terminals as childs of urxvtd by typing urxvtc. Another advantage is, that background jobs are always owned by the urxvtd and will survive as long the daemon is running.

This command will output 1 if the given argument is a valid ip address and 0 if it is not.

Files containing ascii art (e.g. with .nfo extension) are typically not correctly reproduced at the command line when using cat. With iconv one can easily write a wrapper to solve this: