\chapter{Generic Operating System Services} The modules described in this chapter provide interfaces to operating system features that are available on (almost) all operating systems, such as files and a clock. The interfaces are generally modelled after the \UNIX{} or C interfaces but they are available on most other systems as well. Here's an overview: \begin{description} \item[os] --- Miscellaneous OS interfaces. \item[time] --- Time access and conversions. \item[getopt] --- Parser for command line options. \item[tempfile] --- Generate temporary file names. \item[errno] --- Standard errno system symbols. \item[glob] --- \UNIX{} shell style pathname pattern expansion. \item[fnmatch] --- \UNIX{} shell style pathname pattern matching. \item[locale] --- Internationalization services. \end{description}