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Debug SSH at the Maximum Verbosity Level
When debugging an ssh connection either to optimize your settings ie compression, ciphers, or more commonly for debugging an issue connecting, this alias comes in real handy as it's not easy to remember the '-o LogLevel=DEBUG3' argument, which adds a boost of debugging info not available with -vvv alone. Especially useful are the FD info, and the setup negotiation to create a cleaner, faster connection.

a function to find the fastest DNS server
http://public-dns.info gives a list of online dns servers. you need to change the country in url (br in this url) with your country code. this command need some time to ping all IP in list.

Find files and calculate size of result in shell
Using find's internal stat to get the file size is about 50 times faster than using -exec stat.

exim statistics about mails from queue
statistics are sorted based on number of recipients.

BackTrack Repos
Add the BackTrack repositories to your Debian based GNU/Linux distribution. Thanks to http://it-john.com/home/technology/linux-technology/add-back-track-4-repo-to-ubuntu/

Show the number of current httpd processes

strip non-constant number of directories from tar archive while decompressing
If you want to decompress the files from an archive to current directory by stripping all directory paths, use --transform option to strip path information. Unfortunately, --strip-components option is good if the target files have same and constant depth of folders. The idea was taken from http://www.unix.com/solaris/145941-how-extract-files-tar-file-without-creating-directories.html

floating point operations in shell scripts
-l auto-selects many more digits (but you can round/truncate in your head, right) plus it loads a few math functions like sin().

reduce mp3 bitrate (and size, of course)
Useful if you have to put some mp3 files into mobile devices (ie mobile phones with no much memory)

Convert from octal format to umask
Umask is obtained subtracting 7 from each cypher of octal format. I store octal perm format in an array,then for each element of array I subtract 7. The result is the umask.


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