Scroll to navigation

App::Info::RDBMS::PostgreSQL(3pm)

User Contributed Perl Documentation

App::Info::RDBMS::PostgreSQL(3pm)

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:

Executing `pg_config --version`

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

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:

Executing `pg_config --version`

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

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:

Executing `pg_config --version`

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

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:

Executing `pg_config --version`

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

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:

Executing `pg_config --version`

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

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.

2022-12-06

perl v5.36.0