\documentclass{article}\usepackage{../style}\usepackage{../langs}\usetikzlibrary{patterns,decorations.pathreplacing}\begin{document}\section*{Handout 4 (Unix-Style Access Control)}Access control is essentially about deciding whether to grantaccess to a resource or deny it. This sounds easy. Right? Wellit turns out that things are not as simple as seem at first.Let us study as a case how access is organised in Unix-likesystems (Windows systems have generally similar accesscontrol, although the details might be quite different).Following the Unix-philosophy that everything is considered asa file, even memory or ports, access control is organisedaround 11 Bits that specify how a file can be accessed. Thereare three modes for access \textbf{r}ead, \textbf{w}rite ande\textbf{x}ecute. Moreover there are .... owner, group andeverybody else.\end{document}%%% Local Variables: %%% mode: latex%%% TeX-master: t%%% End: