Commands by rubo77 (8)

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tar+pbzip2 a dir

Sending a file over icmp with hping
you need to start a listening hping on the reciever: hping3 --listen 10.0.2.254 -I eth0 --sign MSGID1 then you can send your file: hping3 10.0.2.254 --icmp --sign MSGID1 -d 50 -c 1 --file a_file

Display IP : Count of failed login attempts
The lastb command presents you with the history of failed login attempts (stored in /var/log/btmp). The reference file is read/write by root only by default. This can be quite an exhaustive list with lots of bots hammering away at your machine. Sometimes it is more important to see the scale of things, or in this case the volume of failed logins tied to each source IP. The awk statement determines if the 3rd element is an IP address, and if so increments the running count of failed login attempts associated with it. When done it prints the IP and count. The sort statement sorts numerically (-n) by column 3 (-k 3), so you can see the most aggressive sources of login attempts. Note that the ':' character is the 2nd column, and that the -n and -k can be combined to -nk. Please be aware that the btmp file will contain every instance of a failed login unless explicitly rolled over. It should be safe to delete/archive this file after you've processed it.

Fetch the requested virtual domains and their hits from log file
The command will read the apache log file and fetch the virtual host requested and the number of requests.

find which lines in a file are longer than N characters
Filter out lines of input that contain 72, or fewer, characters. This uses bash only. ${#i} is the number of characters in variable i.

Bytebeat
Never ending music, generated via a C snippet, piped to aplay. Taken from: http://canonical.org/~kragen/bytebeat/

seq (argc=2) for FreeBSD

Rename files in batch

run command on a group of nodes in parallel

cycle through a 256 colour palette
Rainbow, instead of greys


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