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Delete empty directories recursively

Deal with dot files safely

Find the process you are looking for minus the grepped one
Get the PID of a process by name

Protect directory from an overzealous rm -rf *
Forces the -i flag on the rm command when using a wildcard delete.

Update your OpenDNS network ip
Intended for dynamic ip OpenDNS users, this command will update your OpenDNS network IP. For getting your IP, you can use one of the many one-liners here on commandlinefu. Example: I use this in a script which is run by kppp after it has successfully connected to my ISP: --- #!/bin/bash IP="`curl -s http://checkip.dyndns.org/ | grep -o '[[:digit:].]\+'`" PW="hex-obfuscated-pw-here" if [ "$IP" == "" ] ; then echo 'Not online.' ; exit 1 else wget -q --user=topsecret --password="`echo $PW | xxd -ps -r`" 'https://updates.opendns.com/nic/update?hostname=myhostname&myip='"$IP" -O - /etc/init.d/ntp-client restart & fi --- PS: DynDNS should use a similar method, if you know the URL, please post a comment. (Something with members.dyndns.org, if I recall correctly)

Find artist and title of a music cd, UPC code given (first result only)
I like curl better than wget, I just think that curl -s is a lot simpler than wget ... see I forget what you even have to do to get wget to pipe it's output Anyway, all in one sed command as "requested"

add static arp entry to default gateway, arp poison protection

output the contents of a file removing any empty lines including lines which contain only spaces or tabs.

Ping all hosts on 192.168.1.0/24
Pings all the hosts on 192.168.1.0/24 in parallel, so it is very fast. Alive host IP addresses are echoed to stdout as pings are responded to.

Destroy all disks on system simultaneously
This command will use the fdisk utility to find all block devices on your system, and overwrite them with data from the /dev/urandom non-blocking random number generator. CAUTION: This will irrevocably erase EVERY SINGLE physical block storage device visible to the fdisk utility, including plugged USB devices, RAID sets, LVM, etc.


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