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Efficiently extract lines between markers
GNU Sed can 'address' between two regex, but it continues parsing through to the end of the file. This slight alteration causes it to terminate reading the input file once the STOP match is made. In my example I have included an extra '/START/d' as my 'start' marker line contains the 'stop' string (I'm extracting data between 'resets' and using the time stamp as the 'start'). My previous coding using grep is slightly faster near the end of the file, but overall (extracting all the reset cycles in turn) the new SED method is quicker and a lot neater.

Realtime lines per second in a log file
Displays the realtime line output rate of a logfile. -l tels pv to count lines -i to refresh every 10 seconds -l option is not in old versions of pv. If the remote system has an old pv version: ssh tail -f /var/log/apache2/access.log | pv -l -i10 -r >/dev/null

Rename .JPG to .jpg recursively
This command is useful for renaming a clipart, pic gallery or your photo collection. It will only change the big caps to small ones (on the extension).

Backup entire directory using rsync

Watch TCP, UDP open ports in real time with socket summary.

Safely remove old unused kernels in Ubuntu/Debian
Removes piling kernels from /boot, save the current one. This command DOES NOT remove the 'linux-image-generic' package, so you'll continue getting kernel updates

processes per user counter
No need for sort

floating point operations in shell scripts
using bc is for sissies. dc is much better :-D Polish notation will rule the world...

Install pip with Proxy
Installs pip packages defining a proxy

Get all IPs via ifconfig
The initial version of this command also outputted extra empty lines, so it went like this: 192.168.166.48 127.0.0.1 This happened on Ubuntu, i haven't tested on anything else.


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