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watch iptables counters
Watch the number of packets/bytes coming through the firewall. Useful in setting up new iptables rules or chains. Use this output to reorder rules for efficiency.

generate random number

Detect illegal access to kernel space, potentially useful for Meltdown detection
Based on capsule8 agent examples, not rigorously tested

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"

Extract JPEG images from a PDF document
This will extract all DCT format images from foo.pdf and save them in JPEG format (option -j) to bar-000.jpg, bar-001.jpg, bar-002.jpg, etc. Inspired by http://stefaanlippens.net/extract-images-from-pdf-documents

Identify long lines in a file
This command displays a list of lines that are longer than 72 characters. I use this command to identify those lines in my scripts and cut them short the way I like it.

Get the current svn branch/tag (Good for PS1/PROMPT_COMMAND cases)
uses just one sed

Tree based ps view "painted" by ccze

grep tab (\t)
works in bash

Create a 5 MB blank file via a seek hole
Similar to the original, but is much faster since it only needs to write the last byte as zero. A diff on testfile and testfile.seek will return that they are the same.


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