Commands by pichinep (1)

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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

DVD to YouTube ready watermarked MPEG-4 AVI file using mencoder (step 2)
Reencodes to MPEG-4 DivX output video file from step 1. Audio stream is simply copied. Resizes to 320x240 and deinterlaces as needed. A heading subtitle file is applied as watermark. This heading subtitle file can be a URL.

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"

route output as next command's parameters

Check for Firewall Blockage.
This is just one method of checking to see if an IP is blocked via IP tables or CSF. Simple and to the point. Replace xx.xx.xx.xx with the IP you wish to check.

Swap a file or dir with quick resotre
This lets you replace a file or directory and quickly revert if something goes wrong. For example, the current version of a website's files are in public_html. Put a new version of the site in public_html~ and execute the command. The names are swapped. If anything goes wrong, execute it again (up arrow or !!).

Prepend text to a file

Summarize the number of open TCP connections by state
Useful for checking the number and state of TCP connections.

Matrix Style
Solves "tr" issues with non C-locales under BSD-like systems (like OS X)

Display a block of text with AWK
I find this terribly useful for grepping through a file, looking for just a block of text. There's "grep -A # pattern file.txt" to see a specific number of lines following your pattern, but what if you want to see the whole block? Say, the output of "dmidecode" (as root): $ dmidecode | awk '/Battery/,/^$/' Will show me everything following the battery block up to the next block of text. Again, I find this extremely useful when I want to see whole blocks of text based on a pattern, and I don't care to see the rest of the data in output. This could be used against the '/etc/securetty/user' file on Unix to find the block of a specific user. It could be used against VirtualHosts or Directories on Apache to find specific definitions. The scenarios go on for any text formatted in a block fashion. Very handy.


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