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man pages section 8: System Administration Commands

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Updated: Wednesday, February 9, 2022

squid (8)


squid - HTTP web proxy caching server


squid  [-dhisrvzCFNRSVYX] [--foreground] [-l facility ] [-f config-file
] [-[au] port ] [-k signal ] [-n service-name ] [-O command-line ]


squid(8)                    System Manager's Manual                   squid(8)

       squid - HTTP web proxy caching server

       squid  [-dhisrvzCFNRSVYX] [--foreground] [-l facility ] [-f config-file
       ] [-[au] port ] [-k signal ] [-n service-name ] [-O command-line ]

       squid is a high-performance proxy caching server for web clients,  sup-
       porting  FTP,  gopher,  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 log-
       ging.  By using the lightweight Internet Cache Protocols ICP,  HTCP  or
       CARP,  Squid  caches  can  be arranged in a hierarchy or mesh for addi-
       tional 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  http://wiki.squid-cache.org/  ,  or
       the  configuration  manual  on  the  Squid  home page http://www.squid-

       -a port     Specify HTTP port number  where  Squid  should  listen  for
                   requests,  in  addition  to any http_port specifications in

       -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  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.

                   Parent  process  does not exit until its children have fin-
                   ished. It has no effect with -N which does not fork/exit at

       --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

       -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

       -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 con-
                   figured 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 configu-
                   ration 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.

       Squid configuration files located in /etc/squid/:

              The main configuration file. You must initially make changes  to
              this file for squid to work. For example, the default configura-
              tion only allows access from RFC  private  LAN  networks.   Some
              packaging distributions block even that.

              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  syn-
              tax after upgrading.

              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 man-
              ual is also available for a full  reference  of  options.   see-

              The main configuration file for the web cachemgr.cgi tools.

              The main configuration file for the Sample MSNT authenticator.

              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:

       /etc/squid/mime.conf (mime_table)
              MIME type mappings for FTP gatewaying

              Location of Squid error pages and templates.

       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-

       With contributions from many others in the Squid community.   see  CON-
       TRIBUTORS  for  a  full  list of individuals who contributed code.  see
       CREDITS for a list of major code contributing copyright holders.

        * Copyright (C) 1996-2021 The Squid Software Foundation and  contribu-
        * 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  on  the usage of this program can be sent to the Squid Users
       mailing list <squid-users@lists.squid-cache.org>

       Bug reports  need  to  be  made  in  English.   See  http://wiki.squid-
       cache.org/SquidFaq/BugReporting for details of what you need to include
       with your bug report.

       Report bugs or bug fixes using http://bugs.squid-cache.org/

       Report serious security bugs  to  Squid  Bugs  <squid-bugs@lists.squid-

       Report  ideas for new improvements to the Squid Developers mailing list

       See attributes(7) for descriptions of the following attributes:

       |Availability   | web/proxy/squid  |
       |Stability      | Uncommitted      |

       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
       The Squid FAQ wiki http://wiki.squid-cache.org/SquidFaq
       The Squid Configuration Manual http://www.squid-cache.org/Doc/config/

       Source code for open source software components in Oracle  Solaris  can
       be found at https://www.oracle.com/downloads/opensource/solaris-source-

       This    software    was    built    from    source     available     at
       https://github.com/oracle/solaris-userland.    The  original  community
       source    was    downloaded    from     http://www.squid-cache.org/Ver-

       Further information about this software can be found on the open source
       community website at http://www.squid-cache.org/.