[ Thanks to LogError for this link.
]
“The book starts with an overview of GNU/Linux and its many
features. Sobell provides a lot of information dedicated to novice
users: logging in and out, using the documentation, basic
utilities, etc. The author makes a security recommandation when
writing about passwords. He underlines the importance of using
passwords, protecting them, choosing the right type of password and
using the passwd utility.“We learn about the many GNU/Linux utilities that you can use to
work with files, obtain system and user information, communicate
with other users, use e-mail, and so on. When discussing utilities
that can help you to obtain user and system information, the author
mentiones who, finger and w. He notes that if you’re concerned
about security you might want to disable finger, since it can give
out information that might be of help to an intruder.“The GNU/Linux filesystem is covered with a lot of information
including: directories, filenames, pathnames and links. This
overview touches security concerns as Sobell introduces security
permissions. He explains how executable files that are setuid work
and advises never to write setuid shell scripts since there are
several techniques that can be used to subvert them. The author
explains what the shell is and covers the command line, standard
input and standard output, redirection, pipes, special characters,
and more…”