bash_output.txt

obsidian@lithion-mint ~/Documents $ php benchmark.php
file - 0.212994 seconds
obsidian@lithion-mint ~/Documents $ php benchmark.php
file - 0.204549 seconds
obsidian@lithion-mint ~/Documents $ php benchmark.php
file - 0.200732 seconds
obsidian@lithion-mint ~/Documents $ php benchmark.php
file - 0.207176 seconds
obsidian@lithion-mint ~/Documents $ php benchmark.php
file - 0.210159 seconds
obsidian@lithion-mint ~/Documents $ php benchmark.php
fgets - 0.188541 seconds
obsidian@lithion-mint ~/Documents $ php benchmark.php
fgets - 0.163778 seconds
obsidian@lithion-mint ~/Documents $ php benchmark.php
fgets - 0.163242 seconds
obsidian@lithion-mint ~/Documents $ php benchmark.php
fgets - 0.164689 seconds
obsidian@lithion-mint ~/Documents $ php benchmark.php
fgets - 0.166871 seconds
obsidian@lithion-mint ~/Documents $ 

benchmark.php

<?php
$mode = 'fgets';
benchmark();
for($i = 0; $i <= 2000; $i++)
{
	try
	{
		// blah blah 123
		throw new Exception('test');
	}
	catch(Exception $e)
	{

		if($mode == 'fgets')
			getErrorContextFgets($e->getFile(), $e->getLine(), 4);
		elseif($mode == 'file')
			getErrorContextFile($e->getFile(), $e->getLine(), 4);
	}
}
echo $mode . ' - ';
benchmark();
die();




function getTime()
{
	$timer = explode(' ', microtime());
	return $timer[1] + $timer[0];
}

function benchmark()
{
	static $start = 0;

	if(!$start)
		$start = getTime();
	else
		echo round(getTime() - $start, 6) . ' seconds' . PHP_EOL;
}

function getErrorContextFile($file, $line, $context = 3)
{
	$return = array();
	foreach (file($file) as $i => $str)
	{
		if (($i + 1) < ($line + $context) && ($i + 1) > ($line - $context))
		{
			$return[] = $str;
		}
	}

	return $return;
}

function getErrorContextFgets($file, $line, $context = 3)
{
	$return = '';
	$line_i = 0;
	if($fh = fopen($file,"r"))
	{
		while (!feof($fh))
		{
			$line_i++;
			if($line_i > ($line - $context))
			{
				if($line_i < ($line + $context))
					break;
				$return[] = fgets($fh);
			}
			else
			{
				fgets($fh);
			}
		}
		fclose($fh);
	}
	return $return;
}

Alright, here's my results: http://gist.github.com/408354#file_benchmark.txt