Provided by: squid-openssl_6.13-0ubuntu0.24.04.2_amd64 

NAME
squid - HTTP web proxy caching server
SYNOPSIS
squid [-dhisrvzCFNRSVYX] [--foreground] [-l facility ] [-f config-file ] [-[au] port ] [-k signal ] [-n
service-name ] [-O command-line ]
DESCRIPTION
squid is a high-performance proxy caching server for web clients, supporting FTP, ICAP, ICP, HTCP and
HTTP data objects. Unlike traditional caching software, Squid handles all requests in a single, non-
blocking process.
Squid keeps meta data and especially hot objects cached in RAM, caches DNS lookups, supports non-blocking
DNS lookups, and implements negative caching of failed requests.
Squid supports SSL, extensive access controls, and full request logging. By using the lightweight
Internet Cache Protocols ICP, HTCP or CARP, Squid caches can be arranged in a hierarchy or mesh for
additional bandwidth savings.
Squid consists of a main server program squid , some optional programs for custom processing and
authentication, and some management and client tools. When squid starts up, it spawns a configurable
number of helper processes, each of which can perform parallel lookups. This reduces the amount of time
the cache waits for results.
Squid is derived from the ARPA-funded Harvest Project.
This manual page only lists the command line arguments. For details on how to configure Squid see the
file /etc/squid/squid.conf.documented, the Squid wiki FAQ and examples at https://wiki.squid-cache.org/ ,
or the configuration manual on the Squid home page http://www.squid-cache.org/Doc/config/
OPTIONS
-a port Specify HTTP port number where Squid should listen for requests, in addition to any http_port
specifications in squid.conf
-C Do not catch fatal signals.
-d level Write debugging to stderr also.
-f file Use the given config-file instead of /etc/squid/squid.conf . If the file name starts with a
! or | then it is assumed to be an external command or command line. Can for example be
used to pre-process the configuration before it is being read by Squid. To facilitate this
Squid also understands the common #line notion to indicate the real source file.
-F Don't serve any requests until store is rebuilt.
-h Print help message.
-i Install as a Windows Service (see -n option).
-k reconfigure | rotate | shutdown | interrupt | kill | debug | check | parse
Parse configuration file, then send signal to running copy (except -k parse ) and exit.
-l facility Use specified syslog facility. Implies -s
-n name Specify Windows Service name to use for service operations, default is: Squid
-N No daemon mode.
--foreground
Parent process does not exit until its children have finished. It has no effect with -N which
does not fork/exit at startup.
--kid roleID
Play a given SMP kid process role, with a given ID. Do not use this option. It is meant for
the master process use only.
-O options Set Windows Service Command line options in Registry.
-r Remove a Windows Service (see -n option).
-R Do not set REUSEADDR on port.
-s Enable logging to syslog. Also configurable in /etc/squid/squid.conf
-S Double-check swap during rebuild.
-u port Specify ICP port number (default: 3130), disable with 0.
-v Print version and build details.
-X Force full debugging.
-Y Only return UDP_HIT or UDP_MISS_NOFETCH during fast reload.
-z Create missing swap directories and other missing cache_dir structures, then exit. All
cache_dir types create the configured top-level directory if it is missing. Other actions are
type-specific. For example, ufs-based storage systems create missing L1 and L2 directories
while Rock creates the missing database file.
This option does not enable validation of any present swap structures. Its focus is on
creation of missing pieces. If nothing is missing, squid -z just exits. If you suspect
cache_dir corruption, you must delete the top-level cache_dir directory before running squid
-z.
By default, squid -z runs in daemon mode (so that configuration macros and other SMP features
work as expected), returning control to the caller before cache_dirs are fully initialized.
If run from init scripts or daemon managers, the caller often needs to wait for the
initialization to complete before proceeding further. Use --foreground option to prevent
premature exits. To disable daemon mode, use -N option.
FILES
Squid configuration files located in /etc/squid/:
squid.conf
The main configuration file. You must initially make changes to this file for squid to work. For
example, the default configuration only allows access from RFC private LAN networks. Some
packaging distributions block even that.
squid.conf.default
Reference copy of the configuration file. Always kept up to date with the version of Squid you are
using.
Use this to look up the default configuration settings and syntax after upgrading.
squid.conf.documented
Reference copy of the configuration file. Always kept up to date with the version of Squid you are
using.
Use this to read the documentation for configuration options available in your build of Squid. The
online configuration manual is also available for a full reference of options.
seehttp://www.squid-cache.org/Doc/config/
cachemgr.conf
The main configuration file for the web cachemgr.cgi tools.
msntauth.conf
The main configuration file for the Sample MSNT authenticator.
errorpage.css
CSS Stylesheet to control the display of generated error pages. Use this to set any company
branding you need, it will apply to every language Squid provides error pages for.
Some files also located elsewhere:
/usr/share/squid/mime.conf (mime_table)
MIME type mappings for FTP gatewaying
/usr/share/squid/errors
Location of Squid error pages and templates.
AUTHOR
Squid was written over many years by a changing team of developers and maintained in turn by Duane
Wessels <duane@squid-cache.org> Henrik Nordstrom <hno@squid-cache.org> Amos Jeffries <amosjeffries@squid-
cache.org>
With contributions from many others in the Squid community. see CONTRIBUTORS for a full list of
individuals who contributed code. see CREDITS for a list of major code contributing copyright holders.
COPYRIGHT
* Copyright (C) 1996-2024 The Squid Software Foundation and contributors
*
* Squid software is distributed under GPLv2+ license and includes
* contributions from numerous individuals and organizations.
* Please see the COPYING and CONTRIBUTORS files for details.
QUESTIONS
Questions on the usage of this program can be sent to the Squid Users mailing list <squid-
users@lists.squid-cache.org>
REPORTING BUGS
Bug reports need to be made in English. See https://wiki.squid-cache.org/SquidFaq/BugReporting for
details of what you need to include with your bug report.
Report bugs or bug fixes using https://bugs.squid-cache.org/
Report serious security bugs to Squid Bugs <squid-bugs@lists.squid-cache.org>
Report ideas for new improvements to the Squid Developers mailing list <squid-dev@lists.squid-cache.org>
SEE ALSO
cachemgr.cgi (8), squidclient (1), basic_pam_auth (8), basic_ldap_auth (8), ext_ldap_group_acl (8),
ext_session_acl (8), ext_unix_group_acl (8),
The Squid FAQ wiki https://wiki.squid-cache.org/SquidFaq
The Squid Configuration Manual http://www.squid-cache.org/Doc/config/
squid(8)