Import UIDS from mail list

<?php
    // By Ryan Griggs - rgriggs@hilltop.net.
    // GPL Licensed.
    // Specify POP3 UIDL file as arg #1
    // Specify dovecot-uidlist file as arg #2
    // Outputs to stdout


    $current_dir = dirname(__FILE__);

    if (count($argv) != 3) { echo "Invalid arguments."; exit(1); }
    $input1 = $argv[1];
    $input2 = $argv[2];

    // Open files
    $f1 = fopen($input1, 'r');
    $f2 = fopen($input2, 'r');

    if ($f1 == false) { echo "Could not open file $input1"; exit(1); }
    if ($f2 == false) { echo "Could not open file $input2"; exit(1); }

    // Read first line of f2 and dump to output
    // (this is the header of the dovecot-uidlist file)
    $line = fgets($f2);
    echo $line;

    // While there is input, read a line from each file and replace the UID

    while ($line = fgets($f1))
    {
    // Find UID in first file.
    $temp = explode('.', $line);    // Format: # [UIDVALIDITY].[UID]
    $uid = $temp[1];
    // Remove \r and \n
    $uid = str_replace("\n", '', $uid);
    $uid = str_replace("\r", '', $uid);

    // Read line from 2nd file and replace UID.
    $line = fgets($f2);
    if (!$line) { echo "Unable to read line from $input2."; exit(1); }

    // Split into appropriate values
    $temp = explode(' ', $line);    // Format: # P[UIDVALIDITY].[UID] :[filename]
    $number = $temp[0];
    $uidstring = $temp[1];
    $filename = $temp[2];
    $filename = str_replace("\n", '', $filename);   // Remove end-of-line chars.
    $filename = str_replace("\r", '', $filename);

    // If numbers don't match:

    // Split uidstring (format P[UIDVALIDITY].[UID]) (discard UID)
    $temp = explode('.', $uidstring);
    $validity = $temp[0];

    // Build and output new string:
    echo "$number $validity.$uid $filename\n";
    }