Hướng dẫn dùng example url trong PHP

Chương trình học

Tác giả: Dương Nguyễn Phú Cường

Ngày đăng: Hồi xưa đó

Ví dụ: //[www.]example.com/subFolder/myfile.php?var=blabla#555

//=================================================== //
//========== self-defined SERVER variables ========== //
//=================================================== //
$_SERVER["DOCUMENT_ROOT"]  🡺 /home/user/public_html
$_SERVER["SERVER_ADDR"]    🡺 143.34.112.23
$_SERVER["SERVER_PORT"]    🡺 80[or 443 etc..]
$_SERVER["REQUEST_SCHEME"] 🡺 https                                         //similar: $_SERVER["SERVER_PROTOCOL"] 
$_SERVER['HTTP_HOST']      🡺         example.com [or with WWW]             //similar: $_SERVER["ERVER_NAME"]
$_SERVER["REQUEST_URI"]    🡺                       /subFolder/myfile.php?var=blabla
$_SERVER["QUERY_STRING"]   🡺                                             var=blabla
__FILE__                   🡺 /home/user/public_html/subFolder/myfile.php
__DIR__                    🡺 /home/user/public_html/subFolder              //same: dirname[__FILE__]
$_SERVER["REQUEST_URI"]    🡺                       /subFolder/myfile.php?var=blabla
parse_url[$_SERVER["REQUEST_URI"], PHP_URL_PATH]🡺  /subFolder/myfile.php 
$_SERVER["PHP_SELF"]       🡺                       /subFolder/myfile.php

// ==================================================================//
//if "myfile.php" is included in "PARENTFILE.php" , and you visit  "PARENTFILE.PHP?abc":
$_SERVER["SCRIPT_FILENAME"]🡺 /home/user/public_html/parentfile.php
$_SERVER["PHP_SELF"]       🡺                       /parentfile.php
$_SERVER["REQUEST_URI"]    🡺                       /parentfile.php?var=blabla
__FILE__                   🡺 /home/user/public_html/subFolder/myfile.php

// =================================================== //
// ================= handy variables ================= //
// =================================================== //
//If site uses 
$HTTP_or_HTTPS = [[!empty[$_SERVER['HTTPS']] && $_SERVER['HTTPS']!=='off'] || $_SERVER['SERVER_PORT']==443] ? '//':'//' ];            //in some cases, you need to add this condition too: if ['https'==$_SERVER['HTTP_X_FORWARDED_PROTO']]  ...

//To trim values to filename, i.e. 
basename[$url]             🡺 myfile.php

//excellent solution to find origin
$debug_files = debug_backtrace[];       
$caller_file = count[$debug_files] ? $debug_files[count[$debug_files] - 1]['file'] : __FILE__;

Source: //stackoverflow.com/questions/6768793/get-the-full-url-in-php