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Generate MD5 of string and output only the hash checksum in a readable format
Generates the md5 hash, without the trailing " -" and with the output "broken" into pairs of hexs.

Get a brief overview of how many files and directories are installed
To start, you first need to make sure updatedb has been run/updatedb, and initialized the db: $ su -l root -c updatedb This locate command is provided through the mlocate package, installed by default on most GNU/Linux distributions. It's available on the BSDs as well. Not sure about support for proprietary UNIX systems. The output is self-explanatory- it provides an overview of how many directories and files are on your system.

File rotation without rename command
Rotates log files with "gz"-extension in a directory for 7 days and enumerates the number in file name. i.e.: logfile.1.gz > logfile.2.gz I needed this line due to the limitations on AIX Unix systems which do not ship with the rename command.

tmux start new session with title and execute command
in this examp start htop command in tmux session over the shell cosole and set title for the tmux without doing it manuelly in tmux

Indicates the position of my monitor buttons
I often need to change the brightness of my monitor. The symbols of the sensor buttons are not illuminated and on a black background .... invisible! Now i use osd_cat instead of a torch ;-)

Remote screenshot
Say if you're logged into a remote system via ssh and this system has an x window system, but yet you still want a screen shot of what's going on graphically. This will do it for you. :-)

See entire packet payload using tcpdump.
This command will show you the entire payload of a packet. The final "s" increases the snaplength, grabbing the whole packet.

Add temporary swap space
In addition to a swap partition, Linux can also use a swap file. Some programs, like g++, can use huge amounts of virtual memory, requiring the temporary creation of extra space.

Find default gateway

get stdout to variable and stdout at sametime
Sometimes you want to write the script output to stdout but you need to send it to email. If you use: $ var="$( ls / )"; $ echo -e "$var"; works but, you need to wait the script terminate to bufferize then print the output var; With this way, you can use/work/print the output before the variable receive all the output content, then after it you can use the variable for anything else, like send email.


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