Commands by zmonkey (1)

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Rename files in batch

move up through directories faster (set in your /etc/profile or .bash_profile)
Usage: $ up N I did not like two things in the submitted commands and fixed it here: 1) If I do cd - afterwards, I want to go back to the directory I've been before 2) If I call up without argument, I expect to go up one level It is sad, that I need eval (at least in bash), but I think it's safe here. eval is required, because in bash brace expansion happens before variable substitution, see http://rosettacode.org/wiki/Repeat_a_string#Using_printf

Find usb device in realtime
Using this command you can track a moment when usb device was attached.

Open a manpage in the default (graphical) web browser
An easy alias for opening a manpage, nicely HTML formatted, in your set internet browser. If you get a "command exited with status 3" error you need to install groff.

Use a var with more text only if it exists
See "Parameter Expansion" in the bash manpage. They refer to this as "Use Alternate Value", but we're including the var in the at alternative.

Encrypted archive with openssl and tar
The lifehacker way: http://lifehacker.com/software/top/geek-to-live--encrypt-your-data-178005.php#Alternate%20Method:%20OpenSSL "That command will encrypt the unencrypted-data.tar file with the password you choose and output the result to encrypted-data.tar.des3. To unlock the encrypted file, use the following command:" $ openssl des3 -d -salt -in encrypted-data.tar.des3 -out unencrypted-data.tar

Diff on two variables
You got some results in two variables within your shell script and would like to find the differences? Changes in process lists, reworked file contents, ... . No need to write to temporary files. You can use all the diff parameters you'll need. Maybe anything like $ grep "^>" is helpful afterwards.

Switch to a user with "nologin" shell
You need sudo privileges for this command. Replace username with actual username.

Remove all zero size files from current directory (not recursive)

How to trim a video using ffmpeg
Will trim the video to 4 seconds starting from the beginning. The -vcodec , -acodec options are required so that ffmpeg knows in what video/audio format you want for the new video.


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