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Test network speed without wasting disk
The above command will send 4GB of data from one host to the next over the network, without consuming any unnecessary disk on either the client nor the host. This is a quick and dirty way to benchmark network speed without wasting any time or disk space. Of course, change the byte size and count as necessary. This command also doesn't rely on any extra 3rd party utilities, as dd, ssh, cat, /dev/zero and /dev/null are installed on all major Unix-like operating systems.

check open ports without netstat or lsof

Backup your hard drive with dd
This will create an exact duplicate image of your hard drive that you can then restore by simply reversing the "if" & "of" locations. $ sudo dd if=/media/disk/backup/sda.backup of=/dev/sda Alternatively, you can use an SSH connection to do your backups: $dd if=/dev/sda | ssh user@ssh.server.com dd of=~/backup/sda.backup

Limit the cpu usage of a process
Similar to `cpulimit`, although `prlimit` can be found shipped with recent util-linux. Example: limit CPU consumption to 10% for a math problem which ordinarily takes up 100% CPU: Before: $ bc -l

Create QR codes from a URL.
QR codes are those funny square 2d bar codes that everyone seems to be pointing their smart phones at. Try the following... $ qrurl http://xkcd.com Then open qr.*.png in your favorite image viewer. Point your the bar code reader on your smart phone at the code, and you'll shortly be reading xkcd on your phone. URLs are not the only thing that can be encoded by QR codes... short texts (to around 2K) can be encoded this way, although this function doesn't do any URL encoding, so unless you want to do that by hand it won't be useful for that.

Top 10 Memory Processes
It displays the top 10 processes sorted by memory usage

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Testing php configuration

Show your account and windows policy settings with Results of Policy msc.
Type this into windows via run and it will display to you your complete policy for windows. This includes group policy, security policy and your active directory account (min password etc).... www.fir3net.com

Donwload media from *.rm from an url of type htttp://.../*.ram


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