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RTFM function
Simple edit to work for OSX. Now just add this to your ~/.profile and `source ~/.profile`

Backticks are evil
This is a simple example of using proper command nesting using $() over ``. There are a number of advantages of $() over backticks. First, they can be easily nested without escapes: $ program1 $(program2 $(program3 $(program4))) versus $ program1 `program2 \`program3 \`program4\`\`` Second, they're easier to read, then trying to decipher the difference between the backtick and the singlequote: `'. The only drawback $() suffers from is lack of total portability. If your script must be portable to the archaic Bourne shell, or old versions of the C-shell or Korn shell, then backticks are appropriate, otherwise, we should all get into the habit of $(). Your future script maintainers will thank you for producing cleaner code.

backup with mysqldump a really big mysql database to a remote machine over ssh
backup big mysql db to remote machine over ssh. "--skip-opt" option is needed when you can?t allocate full database in ram.

Send a backup job to a remote tape drive on another machine over SSH
I use this all the time for taking manual backups of stuff i want to keep but not important enough to backup regularly.

Show the disk usage for files pointed by symbolic link in a directory
You also can sum the file usage of all files $ find /usr/lib -maxdepth 1 -type l -print0 | xargs -r0 du -Lch

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"

Learn the difference between single and double quotes

adjust laptop display hardware brightness [non root]

Recursive Line Count
We use `-not -name ".*"` for the reason we must omit hidden files (which unnecessary). We can only show up total lines like this: $ find * -type f -not -name ".*" | xargs wc -l | tail -1

Find brute force attempts on SSHd
Searches the /var/log/secure log file for Failed and/or invalid user log in attempts.


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