I recently bought a pdf book. It was password-protected (40bit security). Unfortunately some of the PDF viewers on Linux cannot open password-protected pdf files. So I decided that I can remove the password protection for private use.
A quick lock at the web showed two very easy methods of password removal:
I have an old Psion 3a which I use mainly as an alarm clock during vacation when I have to catch a train or plane. To make it more useful, I decided to put all my addresses to its database. The database format is some strange format (.dbf). The database application of the Psion 3a cannot import any other format and the only format it can export in is a text file where each field is seperated from the next by a delimiter character (by default linefeed) and each record is seperated from the next by an empty line (or an empty line if linefeed is the delimiter).
The command rpm2cpio finger-0.17-9.i386.rpm | cpio -imVd extracts all files from the rpm archive finger-0.17-9.i386.rpm. It creates the directory structure relative to the current directory.