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:
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 only the first value from the
config file. (This option uses the letter
"a" because in the Harvest cache,
the HTTP port was called the ASCII port.)
Makes Squid write its debugging messages to
stderr (as well as
cache.log and syslog, if configured). The
level argument specifies the maximum level
for messages that should be shown on stderr. In
most cases -d1 works well. See Section 16.2 for a description of debugging levels.
Specifies an alternate configuration
Displays the usage information.
Signals Squid to perform various
administrative functions. The function
argument may be one of the following: reconfigure,
debug, check, or
parse. reconfigure causes the
running Squid process to reread its configuration file.
rotate causes Squid to rotate its log files, which
involves closing them, possibly renaming them, and opening them
again. shutdown sends the signal to shut down the
Squid process. interrupt also shuts down Squid but
does so immediately, without waiting for active transactions to
finish. kill sends the unstoppable KILL signal to
Squid, which should only be used as a last resort.
debug puts Squid into full debugging mode. It can
quickly fill up your disk space if your cache is busy.
check simply checks for a running Squid process.
The process return value indicates whether Squid is running or not.
Finally, parse simply parses the
squid.conf file. The process return value is
non-zero if the configuration file contains errors.
Enables logging to the syslog daemon. Squid
uses the LOCAL4 syslog facility. Level 0 debug
messages are logged with priority LOG_WARNING, and
level 1 messages are logged with LOG_NOTICE.
Higher level debugging messages aren't sent to
syslogd. You might use an entry like this in
Specifies an alternate ICP port number, overriding
icp_port in squid.conf.
Prints the version string.
Initializes cache, or swap, directories.
You must use this option when running Squid for the first time or
whenever you add a new cache directory.
Prevents the installation of signal handlers that trap certain
fatal signals such as SIGBUS and SIGSEGV. Normally, the signals are
trapped by Squid so that it can attempt a clean shutdown. However,
trapping the signal may make it harder to debug the problem
afterwards. With this option, the fatal signals cause their default
actions, which is usually to dump core.
Disables initial DNS tests. Normally, Squid
won't start until it verifies that its DNS server is
working. This option prevents that check. You can also alter or
remove the dns_testnames option in
Makes Squid refuse all requests until it
rebuilds the storage metadata. If your cache is busy, this option may
shorten the time required to rebuild the metadata. If your cache is
large, however, the rebuild procedure may take a long time anyway.
Prevents Squid from becoming a background
Prevents Squid from using the
SO_REUSEADDR option before binding to the HTTP
Enables virtual host surrogate mode. Similar
to entering httpd_accel_host virtual in
Forces full debugging, as though you had
specified debug_options ALL,9 in
Returns ICP_MISS_NOFETCH instead
ICP_MISS when rebuilding store metadata. For busy
parent caches, this option may result in less load while the cache is
rebuilding. See Section 10.6.1.2.