Squid: The Definitive Guide

Chapter 5. Running Squid

Now that you have Squid installed, and maybe even configured, you need to learn the ins and outs of running Squid. Although most of the configuration occurs in squid.conf, you may find some of Squid’s command-line options useful. For example, one of the first things you must do is use the -z option to initialize the cache directories. You may also find the -d option useful for debugging.

Squid normally runs as a daemon process. If you are new to Squid, however, I recommend running Squid in the foreground from a terminal window until you are confident that it is working properly. Following that, you can run Squid as a daemon, in the background. Most likely, you’ll want to start Squid each time your system boots. Different operating systems have different approaches to startup scripts. I’ll show you how to make it happen in three different ways.

You can send signals to the running Squid process to execute various tasks, such as halting and reconfiguring Squid, and rotating the log files. Although you can use the kill command to send signals, it is easier to use the squid -k commands.

Squid Command-Line Options

Before getting too far into other things, let’s look at Squid’s command-line options. Many of these you will never use and some are useful only when debugging problems:

-a port

Specifies a new http_port value. This option always overrides the value from squid.conf. Note, however, that you can specify multiple values in squid.conf. The -a option overrides ...