NAME

       App::Info::RDBMS::PostgreSQL - Information about PostgreSQL

SYNOPSIS

         use App::Info::RDBMS::PostgreSQL;

         my $pg = App::Info::RDBMS::PostgreSQL->new;

         if ($pg->installed) {
             print "App name: ", $pg->name, "\n";
             print "Version:  ", $pg->version, "\n";
             print "Bin dir:  ", $pg->bin_dir, "\n";
         } else {
             print "PostgreSQL is not installed. :-(\n";
         }

DESCRIPTION

       App::Info::RDBMS::PostgreSQL supplies information about the PostgreSQL database server installed on the
       local system. It implements all of the methods defined by App::Info::RDBMS. Methods that trigger events
       will trigger them only the first time they're called (See App::Info for documentation on handling
       events). To start over (after, say, someone has installed PostgreSQL) construct a new
       App::Info::RDBMS::PostgreSQL object to aggregate new meta data.

       Some of the methods trigger the same events. This is due to cross-calling of shared subroutines. However,
       any one event should be triggered no more than once. For example, although the info event "Executing
       `pg_config --version`" is documented for the methods "name()", "version()", "major_version()",
       "minor_version()", and "patch_version()", rest assured that it will only be triggered once, by whichever
       of those four methods is called first.

INTERFACE

   Constructor
       new

         my $pg = App::Info::RDBMS::PostgreSQL->new(@params);

       Returns an App::Info::RDBMS::PostgreSQL object. See App::Info for a complete description of argument
       parameters.

       When it called, "new()" searches the file system for an executable named for the list returned by
       "search_exe_names()", usually pg_config, in the list of directories returned by "search_bin_dirs()". If
       found, pg_config will be called by the object methods below to gather the data necessary for each. If
       pg_config cannot be found, then PostgreSQL is assumed not to be installed, and each of the object methods
       will return "undef".

       "new()" also takes a number of optional parameters in addition to those documented for App::Info. These
       parameters allow you to specify alternate names for PostgreSQL executables (other than pg_config, which
       you specify via the "search_exe_names" parameter). These parameters are:

       search_postgres_names
       search_createdb_names
       search_createlang_names
       search_createuser_names
       search_dropd_names
       search_droplang_names
       search_dropuser_names
       search_initdb_names
       search_pg_dump_names
       search_pg_dumpall_names
       search_pg_restore_names
       search_postmaster_names
       search_psql_names
       search_vacuumdb_names

       Events:

       info
           Looking for pg_config

       confirm
           Path to pg_config?

       unknown
           Path to pg_config?

   Class Method
       key_name

         my $key_name = App::Info::RDBMS::PostgreSQL->key_name;

       Returns the unique key name that describes this class. The value returned is the string "PostgreSQL".

   Object Methods
       installed

         print "PostgreSQL is ", ($pg->installed ? '' : 'not '), "installed.\n";

       Returns true if PostgreSQL is installed, and false if it is not.  App::Info::RDBMS::PostgreSQL determines
       whether PostgreSQL is installed based on the presence or absence of the pg_config application on the file
       system as found when "new()" constructed the object. If PostgreSQL does not appear to be installed, then
       all of the other object methods will return empty values.

       name

         my $name = $pg->name;

       Returns the name of the application. App::Info::RDBMS::PostgreSQL parses the name from the system call
       "`pg_config --version`".

       Events:

       info
           Executing `pg_config --version`

       error
           Failed to find PostgreSQL version with `pg_config --version`

           Unable to parse name from string

           Unable to parse version from string

           Failed to parse PostgreSQL version parts from string

       unknown
           Enter a valid PostgreSQL name

       version

         my $version = $pg->version;

       Returns the PostgreSQL version number. App::Info::RDBMS::PostgreSQL parses the version number from the
       system call "`pg_config --version`".

       Events:

       info
           Executing `pg_config --version`

       error
           Failed to find PostgreSQL version with `pg_config --version`

           Unable to parse name from string

           Unable to parse version from string

           Failed to parse PostgreSQL version parts from string

       unknown
           Enter a valid PostgreSQL version number

       major version

         my $major_version = $pg->major_version;

       Returns the PostgreSQL major version number. App::Info::RDBMS::PostgreSQL parses the major version number
       from the system call "`pg_config --version`".  For example, if "version()" returns "7.1.2", then this
       method returns "7".

       Events:

       info
           Executing `pg_config --version`

       error
           Failed to find PostgreSQL version with `pg_config --version`

           Unable to parse name from string

           Unable to parse version from string

           Failed to parse PostgreSQL version parts from string

       unknown
           Enter a valid PostgreSQL major version number

       minor version

         my $minor_version = $pg->minor_version;

       Returns the PostgreSQL minor version number. App::Info::RDBMS::PostgreSQL parses the minor version number
       from the system call "`pg_config --version`".  For example, if "version()" returns "7.1.2", then this
       method returns "2".

       Events:

       info
           Executing `pg_config --version`

       error
           Failed to find PostgreSQL version with `pg_config --version`

           Unable to parse name from string

           Unable to parse version from string

           Failed to parse PostgreSQL version parts from string

       unknown
           Enter a valid PostgreSQL minor version number

       patch version

         my $patch_version = $pg->patch_version;

       Returns the PostgreSQL patch version number. App::Info::RDBMS::PostgreSQL parses the patch version number
       from the system call "`pg_config --version`".  For example, if "version()" returns "7.1.2", then this
       method returns "1".

       Events:

       info
           Executing `pg_config --version`

       error
           Failed to find PostgreSQL version with `pg_config --version`

           Unable to parse name from string

           Unable to parse version from string

           Failed to parse PostgreSQL version parts from string

       unknown
           Enter a valid PostgreSQL minor version number

       executable

         my $exe = $pg->executable;

       Returns the full path to the PostgreSQL server executable, which is named postgres.  This method does not
       use the executable names returned by "search_exe_names()"; those executable names are used to search for
       pg_config only (in "new()").

       When it called, "executable()" checks for an executable named postgres in the directory returned by
       "bin_dir()".

       Note that "executable()" is simply an alias for "postgres()".

       Events:

       info
           Looking for postgres executable

       confirm
           Path to postgres executable?

       unknown
           Path to postgres executable?

       bin_dir

         my $bin_dir = $pg->bin_dir;

       Returns the PostgreSQL binary directory path. App::Info::RDBMS::PostgreSQL gathers the path from the
       system call "`pg_config --bindir`".

       Events:

       info
           Executing `pg_config --bindir`

       error
           Cannot find bin directory

       unknown
           Enter a valid PostgreSQL bin directory

       inc_dir

         my $inc_dir = $pg->inc_dir;

       Returns the PostgreSQL include directory path. App::Info::RDBMS::PostgreSQL gathers the path from the
       system call "`pg_config --includedir`".

       Events:

       info
           Executing `pg_config --includedir`

       error
           Cannot find include directory

       unknown
           Enter a valid PostgreSQL include directory

       lib_dir

         my $lib_dir = $pg->lib_dir;

       Returns the PostgreSQL library directory path. App::Info::RDBMS::PostgreSQL gathers the path from the
       system call "`pg_config --libdir`".

       Events:

       info
           Executing `pg_config --libdir`

       error
           Cannot find library directory

       unknown
           Enter a valid PostgreSQL library directory

       so_lib_dir

         my $so_lib_dir = $pg->so_lib_dir;

       Returns the PostgreSQL shared object library directory path.  App::Info::RDBMS::PostgreSQL gathers the
       path from the system call "`pg_config --pkglibdir`".

       Events:

       info
           Executing `pg_config --pkglibdir`

       error
           Cannot find shared object library directory

       unknown
           Enter a valid PostgreSQL shared object library directory

       configure options

         my $configure = $pg->configure;

       Returns the options with which the PostgreSQL server was configured. App::Info::RDBMS::PostgreSQL gathers
       the configure data from the system call "`pg_config --configure`".

       Events:

       info
           Executing `pg_config --configure`

       error
           Cannot find configure information

       unknown
           Enter PostgreSQL configuration options

       home_url

         my $home_url = $pg->home_url;

       Returns the PostgreSQL home page URL.

       download_url

         my $download_url = $pg->download_url;

       Returns the PostgreSQL download URL.

       search_exe_names

         my @search_exe_names = $app->search_exe_names;

       Returns a list of possible names for pg_config executable. By default, only pg_config is returned (or
       pg_config.exe on Win32).

       Note that this method is not used to search for the PostgreSQL server executable, only pg_config.

       search_bin_dirs

         my @search_bin_dirs = $app->search_bin_dirs;

       Returns a list of possible directories in which to search an executable. Used by the "new()" constructor
       to find an executable to execute and collect application info. The found directory will also be returned
       by the "bin_dir" method.

       The list of directories by default consists of the path as defined by "File::Spec->path", as well as the
       following directories:

       $ENV{POSTGRES_HOME}/bin (if $ENV{POSTGRES_HOME} exists)
       $ENV{POSTGRES_LIB}/../bin (if $ENV{POSTGRES_LIB} exists)
       /usr/local/pgsql/bin
       /usr/local/postgres/bin
       /opt/pgsql/bin
       /usr/local/bin
       /usr/local/sbin
       /usr/bin
       /usr/sbin
       /bin
       C:\Program Files\PostgreSQL\bin

   Other Executable Methods
       These methods function just like the "executable()" method, except that they return different
       executables. PostgreSQL comes with a fair number of them; we provide these methods to provide a path to a
       subset of them. Each method, when called, checks for an executable in the directory returned by
       "bin_dir()".  The name of the executable must be one of the names returned by the corresponding
       "search_*_names" method.

       The available executable methods are:

       postgres
       createdb
       createlang
       createuser
       dropdb
       droplang
       dropuser
       initdb
       pg_dump
       pg_dumpall
       pg_restore
       postmaster
       psql
       vacuumdb

       And the corresponding search names methods are:

       search_postgres_names
       search_createdb_names
       search_createlang_names
       search_createuser_names
       search_dropd_names
       search_droplang_names
       search_dropuser_names
       search_initdb_names
       search_pg_dump_names
       search_pg_dumpall_names
       search_pg_restore_names
       search_postmaster_names
       search_psql_names
       search_vacuumdb_names

       Events:

       info
           Looking for executable

       confirm
           Path to executable?

       unknown
           Path to executable?

SUPPORT

       This module is stored in an open GitHub repository <http://github.com/theory/app-info/>. Feel free to
       fork and contribute!

       Please file bug reports via GitHub Issues <http://github.com/theory/app-info/issues/> or by sending mail
       to bug-App-Info@rt.cpan.org <mailto:bug-App-Info@rt.cpan.org>.

AUTHOR

       David E. Wheeler <david@justatheory.com> based on code by Sam Tregar <sam@tregar.com>.

SEE ALSO

       App::Info documents the event handling interface.

       App::Info::RDBMS is the App::Info::RDBMS::PostgreSQL parent class.

       DBD::Pg is the DBI driver for connecting to PostgreSQL databases.

       <http://www.postgresql.org/> is the PostgreSQL home page.

COPYRIGHT AND LICENSE

       Copyright (c) 2002-2011, David E. Wheeler. Some Rights Reserved.

       This module is free software; you can redistribute it and/or modify it under the same terms as Perl
       itself.