I have sets of variables storing different settings. How to use a specific set depending on the occasion?

The code is not the cleanest and most beautiful but it solves my problem when the server itself wants to connect to itself, choosing from 3 possible connections with the small variable $dbL

In /follow/config.php

<?PHP

$dbL = "1";// Que servidor é este? 1, 2 ou 3.

$s_ipserver1 = "10.0.0.101";
$db_porta1    = "3306";
$db_user1     = "user";
$db_password1 = "123456";
$db_name1     = "name";

$s_ipserver2 = "xxx.xxx.xxx.xxx";
$db_porta2    = "3306";
$db_user2     = "user";
$db_password2 = "123456";
$db_name2     = "name";

$s_ipserver3 = "xxx.xxx.xxx.xxx";
$db_porta3    = "3306";
$db_user3     = "user";
$db_password3 = "123456";
$db_name3     = "name";
?>

In /follow/subconnect.php

<?php 
include_once("/pasta/config.php");
$ipserver  = '$s_ipserver'. $dbL;
$porta     = '$db_porta'. $dbL;
$user      = '$db_user'. $dbL;
$password  = '$db_password'. $dbL;
$name      = '$db_name'. $dbL;

eval("\$ipserver = \"$ipserver\";");
eval("\$porta = \"$porta\";");
eval("\$user = \"$user\";");
eval("\$password = \"$password\";");
eval("\$name = \"$name\";");
?>

In /pasta/connect.php

<?PHP
include_once("/pasta/subconnect.php");
$host      = "$ipserver:$porta";
$link      = mysql_connect($host, $user, $password) or die (mysql_error ());
$db_connect   = mysql_select_db($name, $link);
?>

And thank you @bfavaretto for the patience and the code you gave me and the others too.

Correction on request of @bfavaretto

Option to /pasta/subconnect.php

<?php 
include_once("/pasta/config.php");
$ipserver  = 's_ipserver'. $dbL;
$porta     = 'db_porta'. $dbL;
$user      = 'db_user'. $dbL;
$password  = 'db_password'. $dbL;
$name      = 'db_name'. $dbL;
// Sem eval()
?>

Option for /pasta/connect.php For without eval ()

<?PHP
include_once("/pasta/subconnect.php");
$host      = $$ipserver . ':'. $$porta;
$link      = mysql_connect($host, $$user, $$password) or die (mysql_error ());
$db_connect   = mysql_select_db($$name, $link);
?>

You can use variable variables , but I find this extremely ugly and confusing:

$dbL = "1";
$s_ipserver1 = "bla";
$servidor = 's_ipserver'. $dbL;
echo $$servidor; // "bla";

It would be more elegant to use arrays:

$servidores = array(
    array(
        's_ipserver' => "10.0.0.101",
        'db_porta'    => "3306",
        'db_user'     => "user",
        'db_password' => "123456",
        'db_name'     => "name",
    ),
    array(
        's_ipserver' => "10.0.0.201",
        'db_porta'    => "3306",
        'db_user'     => "user",
        'db_password' => "98765",
        'db_name'     => "foo"
    )
    // etc
);

$indice = 1;
$servidor = $servidores($indice);
echo $servidor['s_ipserver']; // "10.0.0.201"

You can create individual files for each connection, as suggested by @bfavaretto, create an array containing the indexes:

#pasta/config/database.php
return array(
    'DB1' => array(
             's_ipserver'  => '10.0.0.101',
             'db_porta'    => '3306',
             'db_user'     => 'user',
             'db_password' => '123456',
             'db_name'     => 'name',
             ),

    'DB2' => array(
             's_ipserver'  => 'xxx.xxx.xxx.xxx',
             'db_porta'    => '3306',
             'db_user'     => 'user',
             'db_password' => '123456',
             'db_name'     => 'name',
             ),

    'DB3' => array(
             's_ipserver'  => 'xxx.xxx.xxx.xxx',
             'db_porta'    => '3306',
             'db_user'     => 'user',
             'db_password' => '123456',
             'db_name'     => 'name',
             )
);

Exemplifying array with index

# conn database-1
$conn = include_once('/pasta/config/database.php');
$conn = $conn['DB1'];

// output conexão DB1
Array
(
    [s_ipserver] => 10.0.0.101
    [db_porta] => 3306
    [db_user] => user
    [db_password] => 123456
    [db_name] => name
)

Connection example

$host       = $conn['s_ipserver'] . ':' . $conn['db_porta'];
$db_link    = mysql_connect( $host , $conn['db_user'] , $conn['db_password'] ) or die( mysql_error() );
$db_connect = mysql_select_db( $db_name, $db_link );