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Find recursively, from current directory down, files and directories whose names contain single or multiple whitespaces and replace each such occurrence with a single underscore.
Note the g for global in the perl expression; without it, only the first occurrence in the name would be replaced.

move contents of the current directory to the parent directory, then remove current directory.
I think this is less resource consuming than the previous examples

Get MD5 checksum from a pipe stream and do not alter it

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"

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.

Get AWS temporary credentials ready to export based on a MFA virtual appliance
You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

Quickly graph a list of numbers
Useful when you've produced a large file of numbers, and want to quickly see the distribution. The value of y halfway along the x axis is the median. Simple! Just create the listOfNumbers.txt file with a number on each line to try it out.

Recursively scan directories for mp3s and pass them to mplayer
The command first deletes any old playlist calles playlist.tmp under /tmp. After that it recursively searches all direcotries under ~/mp3 and stores the result in /tmp/playlist.tmp. After havin created the playlist, the command will execute mplayer which will shuffle through the playlist. This command is aliased to m is aliased to `rm -rf /tmp/playlist.tmp && find ~/mp3 -name *.mp3 > /tmp/playlist.tmp && mplayer -playlist /tmp/playlist.tmp -shuffle -loop 0 | grep Playing' in my ~/.bashrc.

Check the age of the filesystem
Very useful set of commands to know when your file system was created.

easily strace all your apache processes
This version also attaches to new processes forked by the parent apache process. That way you can trace all current and *future* apache processes.


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