<?php
    $host = "...";
    $username = "...";
    $password = "...";

    $backupFile = '../backups/sql/allDatabasesBackup'. date("Y-m-d-H-i-s") . '.sql';
    $command = "mysqldump --opt -h $host -u $username -p $password --all-databases > $backupFile";
    system($command);

    /*  File output:
    Usage: mysqldump [OPTIONS] database [tables]
    OR     mysqldump [OPTIONS] --databases [OPTIONS] DB1 [DB2 DB3...]
    OR     mysqldump [OPTIONS] --all-databases [OPTIONS]
    For more options, use mysqldump --help
    */
?>