can anyone explain me this part of the code

[nakkaya]

can anyone explain me this part of the code i couldnt figure it out in detail please this was part of a search engine code named phpdig

//Try to retrieve matching lines if the content-text is set to 1
if (CONTENT_TEXT == 1)
{
$extract = "";
$content_file = $relative_script_path.'/'.TEXT_CONTENT_PATH.$content['spider_id'].'.txt';
if (is_file($content_file))
{
$num_extracts = 0;
$f_handler = fopen($content_file,'r');
while($num_extracts < 5 && $extract_content = fgets($f_handler,1024))
{
if(eregi($reg_strings,$extract_content))
{
$extract .= ' ...'.trim($extract_content).'... ';
$num_extracts++;
}
}
fclose($f_handler);
}
}

[pyfsapple]

As the comment says, it
"Try to retrieve matching lines if the content-text is set to 1"

The first 5 matched lines (if any) are found out and combined together to the result string "$extract", the re-exp pattern is defined by "$reg_strings".

But this code should modified to consider the case of EOF as there may be not more than 4 matched lines.

[nakkaya]

i have a long desc of each page in my database and i am trying to use this code for my database like geting the desc of each page
and printing the 250 letters after one of the keywords but i want the printing to start after one of the searched keywords i spent 3 hours to modify this code but i couldn't thx for the help