–
Description of a Ghostscript command that optimizes a PDF document and reduces its size through a reduction of its quality.
Description of a Ghostscript command that optimizes a PDF document and reduces its size through a reduction of its quality.
A guide on how to extract, reorganize, and manipulate pages of PDF documents using pdftk.
Description of the basic commands to know to use branches in Git.
Short description of the three main sections of a Git project and the corresponding three main states of a file in Git.
Quick guide on how to import or download a key with GnuPG.
Quick guide on how to use the gpg command to decrypt a file.
Quick guide on how to use the gpg command to encrypt a file.
Quick guide on deleting a key from a keyring with GnuPG.
Quick guide on the generation of a new key with GnuPG.
Presentation and practical implementation of OpenSSH certificates to faciliate key based authentication of servers and clients.
How to revoke keys and certificates on OpenSSH to forbid their use in server and client authentication.
Description of filesystem and partition identifiers as alternatives to block devices such as "/dev/sdc3".
The command 'date', among other things, allows printing a date specified relatively to the present or to a specific date, which allows very convenient calculations on dates.
A small example of a trivial shell function that naively converts and prints a number of seconds to hours, minutes and seconds.
A presentation of a simple solution allowing for encryption of the remote connections initiated by rsync using SSH while restricting its accesses to a directory, potentially in read-only mode.
How the array manipulation functionalities specific to bash make it possible to more easily retrieve the positional parameters of a script or function.
How to do a simple loop over the parameters of a shell script, from the first to the last one and from the last to the first one.
The system administrator can force a user to choose a new password on their next connection.
Processing a variable number of fields in text lines using the awk command and its language.
File diversions allow to avoid overwriting local changes to a debian package's file when updating the package.
Quick presentation of network link aggregation on Debian GNU/Linux.
This document describes the procedure to follow to have the BIND DNS server run in a chroot jail on Debian GNU/Linux.