# phpman > man > PG_WRAPPER(1)

[PG_WRAPPER(1)](https://www.chedong.com/phpMan.php/man/PGWRAPPER/1/markdown)                     Debian PostgreSQL infrastructure                     [PG_WRAPPER(1)](https://www.chedong.com/phpMan.php/man/PGWRAPPER/1/markdown)



## NAME
       pg_wrapper - wrapper for PostgreSQL client commands

## SYNOPSIS
       _client-program_ [**--cluster** _version_/_cluster_] [...]

       (_client-program_: **psql**, **createdb**, **dropuser**, and all other client programs installed in
       /usr/lib/postgresql/_version_/bin).

## DESCRIPTION
       This program is run only as a link to names which correspond to PostgreSQL programs in
       /usr/lib/postgresql/_version_/bin. It determines the configured cluster and database for the
       user and calls the appropriate version of the desired program to connect to that cluster and
       database, supplying any specified options to that command.

       The target cluster is selected by the following means, in descending order of precedence:

       1.  explicit specification with the **--host** option

       2.  explicit specification with the **--cluster** option

       3.  if the **PGHOST** environment variable is set, no further cluster selection is performed. The
           default PostgreSQL version and port number (from the command line, the environment
           variable **PGPORT**, or default 5432) will be used.

       4.  explicit specification with the **PGCLUSTER** environment variable

       5.  matching entry in ~/.postgresqlrc (see [**postgresqlrc**(5)](https://www.chedong.com/phpMan.php/man/postgresqlrc/5/markdown)), if that file exists

       6.  matching entry in /etc/postgresql-common/user_clusters (see **user**___**[clusters**(5)](https://www.chedong.com/phpMan.php/man/clusters/5/markdown)), if that
           file exists

       7.  If only one cluster exists on the local system, that one will be selected.

       8.  If several clusters exist on the local system, the one listening on the default port 5432
           will be selected.

       If none of these rules match, **pg**___**wrapper** does not set any environment variables and the
       program called will likely error out with a message like "could not connect to server:
       Connection refused".

       For **psql**, **pg**___**archivecleanup**, and **pg**___**isready**, **pg**___**wrapper** will always use the binary from the
       newest PostgreSQL version installed, as these are downwards compatible.

       Note that **pg**___**wrapper** needs to be able to read the server config to get the port number to
       connect to. If a non-standard port is configured in a place that pg_wrapper cannot read,
       connecting will fail. This particularly holds if the port was configured via **ALTER** **SYSTEM** in
       postgresql.auto.conf and pg_wrapper is invoked as any user other than **postgres** and **root**.

## OPTIONS
       **--cluster** _version_**/**_cluster_
       **--cluster** _version_**/**_host_**:**[_port_]
           _cluster_ is either the name of a cluster on the local system, or takes the form _host_:_port_
           for a remote cluster. If _port_ is left empty (i. e. you just specify _host:_), it defaults
           to 5432.

## ENVIRONMENT
       **PGCLUSTER**
           If $PGCLUSTER is set, its value (of the form _version_/_cluster_) specifies the desired
           cluster, similar to the **--cluster** option. However, if **--cluster** is specified, it
           overrides the value of $PGCLUSTER.

       **PG**___**CLUSTER**___**CONF**___**ROOT**
           This specifies an alternative base directory for cluster configurations. This is usually
           /etc/postgresql/, but for testing/development purposes you can change this to point to e.
           g. your home directory, so that you can use the postgresql-common tools without root
           privileges.

       **PGSYSCONFDIR**
           This is the location of PostgreSQL's and postgresql-common's global configuration (e. g.
           pg_service.conf, **user**___**[clusters**(5)](https://www.chedong.com/phpMan.php/man/clusters/5/markdown)). The default is /etc/postgresql-common/.

## FILES
       /etc/postgresql-common/user_clusters
           stores the default cluster and database for users and groups as set by the
           administrators.

       $HOME/.postgresqlrc
           stores defaults set by the user himself.

## SEE ALSO
       **user**___**[clusters**(5)](https://www.chedong.com/phpMan.php/man/clusters/5/markdown), [**postgresqlrc**(5)](https://www.chedong.com/phpMan.php/man/postgresqlrc/5/markdown)

## AUTHOR
       Martin Pitt <<mpitt@debian.org>>



Debian                                       2022-02-10                                [PG_WRAPPER(1)](https://www.chedong.com/phpMan.php/man/PGWRAPPER/1/markdown)