Commands using pax (4)

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run command on a group of nodes in parallel

Simplest port scanner
Very handy way to perform a host scan if you don't have nmap,ncat,nc ...or other tools installed locally. When executing a command on a /dev/tcp/$host/$port pseudo-device file, Bash opens a TCP connection to the associated socket and UDP connection when using /dev/udp/$host/$port.A simlpe way to get servers banner is to run this command "cat < /dev/tcp/localhost/25" , here you will get mail server's banner. NOTE: Bash, as packaged for Debian, does not support using the /dev/tcp and /dev/udp pseudo-device it's not enabled by default Because bash in Debian is compiled with ?disable-net-redirections.

Show what PID is listening on port 80 on Linux

Benchmark SQL Query
Benchmark a SQL query against MySQL Server. The example runs the query 10 times, and you get the average runtime in the output. To ensure that the query does not get cached, use `RESET QUERY CACHE;` on top in the query file.

Rename files in batch

Remove duplicate entries in a file without sorting.
Using awk, find duplicates in a file without sorting, which reorders the contents. awk will not reorder them, and still find and remove duplicates which you can then redirect into another file.

Execute a command, convert output to .png file, upload file to imgur.com, then returning the address of the .png.
My key is the anonymous one, is good for 50 post an hour with a maximun number of uploads a day, probably will run out, if that happend you can get a free key at the site.

run command on a group of nodes in parallel
Parallel is from https://savannah.nongnu.org/projects/parallel/ Other examples would be: (echo foss.org.my; echo www.debian.org; echo www.freenetproject.org) | parallel traceroute seq -f %04g 0 9999 | parallel -X rm pict{}.jpg

bulk dl files based on a pattern
-O switch creates local filename same as remote curl [][] -o #1#2 makes local files unique inserting sequence values into #x placeholders sequences can be alpha or numeric e.g [a-z] [1-25]

Create incremental backups of individual folders using find and tar-gzip
Problem: I wanted to backup user data individually, using and incremental method. In this example, all user data is located in "/mnt/storage/profiles", and about 25 folders inside, each with a username ( /mnt/storage/profiles/mike; /mnt/storage/profiles/lucy ...) I need each individual folder backed up, not the whole "/mnt/storage/profiles". So, using find while excluding directories depth and creating two variables (tarfile=username & desdir=destination), tar will create a .tgz file for each folder, resulting in a "mike_2013-12-05.tgz" and "lucy_2013-12-05.tgz".


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