Commands by jianingy (9)

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Printable random characters
Reads psuedorandom bytes from /dev/urandom, filtering out non-printable ones. Other character classes can be used, such as [:alpha:], [:digit:] and [:alnum:]. To get a string of 10 lowercase letters: $ tr -dc '[:lower:]' < /dev/urandom | head -c 10

Hardlink all identical files in the current directory (regain some disk space)
Meaning of switches (see man page too): v verbose p ignore mode (permissions) o ignore owner, group t ignore time of modification Disadvantage: If you modify any linked file, this will propagate to all other files which occupy the same space.

rename files according to date created
The command renames all files in a certain directory. Renaming them to their date of creation using EXIF. If you're working with JPG that contains EXIF data (ie. from digital camera), then you can use following to get the creation date instead of stat. * Since not every file has exif data, we want to check that dst is valid before doing the rest of commands. * The output from exif has a space, which is a PITA for filenames. Use sed to replace with '-'. * Note that I use 'echo' before the mv to test out my scripts. When you're confident that it's doing the right thing, then you can remove the 'echo'... you don't want to end up like the guy that got all the files blown away. Credits: http://stackoverflow.com/questions/4710753/rename-files-according-to-date-created

Move cursor to end of line

print line and execute it in BASH
!# is the currennt line so far, by using !#:- you can go from the second arg (it's zero indexed) to the last ($) (did I understand the problem correctly?)

Rename all files in a directory to the md5 hash

Most used command

See your current RAM frequency

Find the package that installed a command

Extract the emoticons regex from a running skype process
Skype has an internal regex which depicts the emoticons it supports. However you cannot simply search the binary file for it. This small 181 character line will do just that, provided skype is running. And of course, only works in linux.


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