Question

Is it possible to shorten this code using preg_replace instead of preg_match?

I am using it to remove quoted text from an email body.
Quoted text being when you quote somebody when you reply to an email.

# Get rid of any quoted text in the email body
# stripSignature removes signatures from the email
# $body is the body of an email (All headers removed)
$body_array = explode("\n", $this->stripSignature($body));
$new_body = "";
foreach($body_array as $key => $value)
{
    # Remove hotmail sig
    if($value == "_________________________________________________________________")
    {
        break;

    # Original message quote
    }
    elseif(preg_match("/^-*(.*)Original Message(.*)-*/i",$value,$matches))
    {
        break;

    # Check for date wrote string
    }
    elseif(preg_match("/^On(.*)wrote:(.*)/i",$value,$matches))
    {
        break;

    # Check for From Name email section
    }
    elseif(preg_match("/^On(.*)$fromName(.*)/i",$value,$matches))
    {
        break;

    # Check for To Name email section
    }
    elseif(preg_match("/^On(.*)$toName(.*)/i",$value,$matches))
    {
        break;

    # Check for To Email email section
    }
    elseif(preg_match("/^(.*)$toEmail(.*)wrote:(.*)/i",$value,$matches))
    {
        break;

    # Check for From Email email section
    }
    elseif(preg_match("/^(.*)$fromEmail(.*)wrote:(.*)/i",$value,$matches))
    {
        break;

    # Check for quoted ">" section
    }
    elseif(preg_match("/^>(.*)/i",$value,$matches))
    {
        break;

    # Check for date wrote string with dashes
    }
    elseif(preg_match("/^---(.*)On(.*)wrote:(.*)/i",$value,$matches))
    {
        break;

    # Add line to body
    }
    else {
        $new_body .= "$value\n";
    }
}

This almost works, but it keeps the first line “On Mon, Jul 30, 2012 at 10:54 PM, Persons Name wrote:”

$body = preg_replace('/(^\w.+:\n)?(^>.*(\n|$))+/mi', "", $body);

Answer 1

There’s probably a more elegant way of doing this, but this should work (assuming the regexps are correct):

$search = array(
  "/^-*.*Original Message.*-*/i",
  "/^On.*wrote:.*/i",
  "/^On.*$fromName.*/i",
  "/^On.*$toName.*/i",
  "/^.*$toEmail.*wrote:.*/i",
  "/^.*$fromEmail.*wrote:.*/i",
  "/^>.*/i",
  "/^---.*On.*wrote:.*/i"
);


$body_array = explode("\n", $this->stripSignature($body));
$body = implode("\n", array_filter(preg_replace($search, '', $body_array)));

// or just

$body = str_replace(
  array("\0\n", "\n\0"), '', preg_replace($search, "\0", $body)
);

Edit: As inhan pointed out, the dots in the email addresses (and potentially other special characters) need to be escaped using preg_quote() prior to being inserted into the patterns.