shows all paths related to installed package

The command below should sync the clock on a unix server to the US timeservers at us.pool.ntp.org.

List files in varying detail

If you need to zip a directory named folderName and ignore all .DS_Store files, then do the following:

insert this to home directory .bashrc file

To find out the current shell

The Python stdlib pwd module provides an easy way to get the primary group ID, but no way to get additional group IDs. This is a simple function that returns the additional group IDs for a given username.

MYSQL Convertir un timestamp en heure lisible

Creating a tar file is easy if you read the spec (you can look it up on wikipedia). Not every kind of files are supported (it support regular files, folders ans symlinks) and it's generating archives for the original tar file format (path length are limited to 100 chars, no extended attributes, ...). It wasn't tested very much but it was a fun hack :) ... I cheated just a little by looking at the python tarfile code from the stdlib for the checksum computation.

A tar file is very simple, it's a list of header/payload for each entry (file|folder|symlink) you want to archive. There's only a payload for file contents. The header is 512 bytes long and can be written in ascii. Numbers (attributes) needs to be written in octal. The files themselves needs to be written in chunks of 512 bytes, which mean you have to fill the last chunk with zeros when the file size is not a multiple of 512 bytes.

Use it like that:

python batar.py /tmp/foo.tar `find .` &&  tar tf /tmp/foo.tar # or xf if you want to extract it