Commands by tictacbum (2)

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Find Duplicate Files (based on MD5 hash) -- For Mac OS X
This works on Mac OS X using the `md5` command instead of `md5sum`, which works similarly, but has a different output format. Note that this only prints the name of the duplicates, not the original file. This is handy because you can add `| xargs rm` to the end of the command to delete all the duplicates while leaving the original.

Download an entire ftp directory using wget
If the username includes an @ you can use this one: wget -r --user=username_here --password=pass_here ftp://ftp.example.com

Find usb device
I often use it to find recently added ou removed device, or using find in /dev, or anything similar. Just run the command, plug the device, and wait to see him and only him

Generate a random password 30 characters long

Get a list of ssh servers on the local subnet
Scan the local network for servers who have the ssh port open.

Getting started with tcpdump
At some point you want to know what packets are flowing on your network. Use tcpdump for this. The man page is obtuse, to say the least, so here are some simple commands to get you started. -n means show IP numbers and don't try to translate them to names. -l means write a line as soon as it is ready. -i eth0 means trace the packets flowing through the first ethernet interface. src or dst w.x.y.z traces only packets going to or from IP address w.x.y.z. port 80 traces only packets for HTTP. proto udp traces only packets for UDP protocol. Once you are happy with each option combine them with 'and' 'or' 'not' to get the effects you want.

Remove multiple same rpm packages
If somehow if you get more than 1 same name rpm package install, then it cannot be removed by using simple rpm -e as it gives you more than one rpm matches error. The --matches will help to remove all the same name rpm packages.

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"

Mount a VMware virtual disk (.vmdk) file on a Linux box
This does not require you to know the partition offset, kpartx will find all partitions in the image and create loopback devices for them automatically. This works for all types of images (dd of hard drives, img, etc) not just vmkd. You can also activate LVM volumes in the image by running $vgchange -a y and then you can mount the LV inside the image. To unmount the image, umount the partition/LV, deactivate the VG for the image $vgchange -a n then run $kpartx -dv to remove the partition mappings.

List your MACs address
List all MAC addresses on a Linux box. sort -u is useful when having virtual interfaces.


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