Print PHP Call Stack

Question

I\'m looking for a way to print the call stack in PHP.

Bonus points if the function flushes the IO buffer.

Answer 1

See debug_print_backtrace. I guess you can call flush afterwards if you want.

Answer 2

var_dump(debug_backtrace());

Does that do what you want?

Answer 3

Backtrace dumps a whole lot of garbage that you don't need. It takes is very long, difficult to read. All you usuall ever want is "what called what from where?" Here is a simple static function solution. I usually put it in a class called 'debug', which contains all of my debugging utility functions.

class debugUtils {
    public static function callStack($stacktrace) {
        print str_repeat("=", 50) ."\n";
        $i = 1;
        foreach($stacktrace as $node) {
            print "$i. ".basename($node['file']) .":" .$node['function'] ."(" .$node['line'].")\n";
            $i++;
        }
    } 
}

You call it like this:

debugUtils::callStack(debug_backtrace());

And it produces output like this:

==================================================
 1. DatabaseDriver.php::getSequenceTable(169)
 2. ClassMetadataFactory.php::loadMetadataForClass(284)
 3. ClassMetadataFactory.php::loadMetadata(177)
 4. ClassMetadataFactory.php::getMetadataFor(124)
 5. Import.php::getAllMetadata(188)
 6. Command.php::execute(187)
 7. Application.php::run(194)
 8. Application.php::doRun(118)
 9. doctrine.php::run(99)
 10. doctrine::include(4)
==================================================

Answer 4

If you want a stack trace which looks very similar to how php formats the exception stack trace than use this function I wrote:

function debug_backtrace_string() {
    $stack = '';
    $i = 1;
    $trace = debug_backtrace();
    unset($trace[0]); //Remove call to this function from stack trace
    foreach($trace as $node) {
        $stack .= "#$i ".$node['file'] ."(" .$node['line']."): "; 
        if(isset($node['class'])) {
            $stack .= $node['class'] . "->"; 
        }
        $stack .= $node['function'] . "()" . PHP_EOL;
        $i++;
    }
    return $stack;
} 

This will return a stack trace formatted like this:

#1 C:\Inetpub\sitename.com\modules\sponsors\class.php(306): filePathCombine()
#2 C:\Inetpub\sitename.com\modules\sponsors\class.php(294): Process->_deleteImageFile()
#3 C:\Inetpub\sitename.com\VPanel\modules\sponsors\class.php(70): Process->_deleteImage()
#4 C:\Inetpub\sitename.com\modules\sponsors\process.php(24): Process->_delete() 

Answer 5

Walltearer's solution is excellent, particularly if enclosed in a 'pre' tag:

<pre>
<?php debug_print_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS); ?>
</pre>

- which sets out the calls on separate lines, neatly numbered

Answer 6

Use debug_backtrace to get a backtrace of what functions and methods had been called and what files had been included that led to the point where debug_backtrace has been called.