Backtrace

debug_backtrace([$i1[,$i2=0]]) returns an associative array containing the backtrace. $i1 can be DEBUG_BACKTRACE_PROVIDE_OBJECT or DEBUG_BACKTRACE_IGNORE_ARGS. $i2 limits the number of stack frames returned. By default ($i2=0) it returns all stack frames. debug_print_backtrace ([$i1[,$i2]]) prints the backtrace. $i1 can be DEBUG_BACKTRACE_IGNORE_ARGS. $i2 limits the number of stack frames used. By default ($i2=0) it prints all stack frames.

test.php:
<?php  // test.php

function a() {b();}
function b() {
   print_r(debug_backtrace());
   echo "<br /><br />";
   debug_print_backtrace();
}
a();
?>

<!DOCTYPE html><html><head></head>
<body><?php
include "test.php";
?> </body></html>

Array ( [0] => Array ( [file] => E:\Program Files\xampp\htdocs\test.php 
                                    [line] => 3
                                    [function] => b 
                                    [args] => Array ( ) ) 
             [1] => Array ( [file] => E:\Program Files\
                                                         xampp\htdocs\test.php                   
                                     [line] => 10 
                                     [function] => a
                                     [args] => Array ( ) ) 
             [2] => Array ( [file] => E:\Program Files\
                                                       xampp\htdocs\intro.php 
                                     [line] => 4 
                                  [args] => Array ( [0] => E:\Program Files\
                                                                xampp\htdocs\test.php )
                                     [function] => include ) )

#0 b() called at [E:\Program Files\xampp\htdocs\test.php:3] 
#1 a() called at [E:\Program Files\xampp\htdocs\test.php:10]
 #2 include(E:\Program Files\xampp\htdocs\test.php) called at [E:\Program Files\xampp\htdocs\intro.php:4]
error_get_last() returns an associative array containing information about the last error, or NULL if there has not been any error.

RESETRUNFULL
<?php  // last-test.php

function a() {b();}
function b() {
   print_r(debug_backtrace());
   echo "<br /><br />";
   debug_print_backtrace();
}
a();
?>

<!DOCTYPE html><html><head></head>
<body><?php
echo $a;
print_r(error_get_last());
?> </body></html>