Builds image moving script

<?php
//// CONNECT TO DATABASE ////
include 'h/1.c/db_connect.php';
include 'i/global_variables.php';
/////////////////////////////

//Store the table name to make it easy to move this code to another Site
$table_name = "antiquesnow_ads";
//Base URL for downloads. Trailing "/" is required
$base_url   = "http://www.antiques-now.co.uk/antiques-for-sale-images/";

//SQL Query to get all picture filenames from teh DB
$result_category = mysql_query("SELECT * FROM $table_name WHERE live >= 1 AND ((pic_name IS NOT NULL)  OR (pic_name != ''))");

//store the field names in an array so we can iterate through them with "foreach"
$field_names = array("pic_name", "pic_name2", "pic_name3", "pic_name4");

//Container for the " " separated list of all the image names
$p_wget_strings = array();
for ($i = 0; $i < 20; $i++)
{ $p_wget_strings[$i] = "";
}
//Counter
$counter = 0;
$p_counter = 0;
//Loop through all the results from the database, and build the string of filenames
while ( $row = mysql_fetch_array($result_category) )
{ foreach ($field_names as $field_name)
  { //Store the value of this field for this record
    $field_value = $row[$field_name];
    //Check if this field_value is NULL or Emtpy
    if (    $field_value != NULL
        &&  $field_value != ""
       )
    { //Add the field_value to the great big string, with the url prefix
      $p_wget_strings[$p_counter] .= " \n".$base_url.$field_value;
      //Increment parrallel counter
      $p_counter++;
      //limit to 20 parrallel wget instances
      if ($p_counter == 20)
      { $p_counter = 0;
      }
      //Increment Counter
      $counter++;
    }
  }
}

$wget_input_file_dir = "~/imageURLs/$table_name";
//build the script
$script_string = "echo About to copy $counter items from $base_url. Y to continue [n]\n";
$script_string .= "read\n";
$script_string .= "if [ \$REPLY = \"Y\" ]\n";
$script_string .= "then\n";
$script_string .= "mkdir -p $wget_input_file_dir\n";
$counter = 0;
foreach ($p_wget_strings as $wget_instance)
{ $counter ++;
  $filename = "imageURLs_$counter";
  echo $filename."\n";
  $full_file_path = $wget_input_file_dir."/".$filename;
  $fileRes = fopen($full_file_path, "w");
  fwrite($fileRes, $wget_instance);
  fclose($fileRes);
  $script_string .=  "  wget -i $full_file_path -o ${wget_input_file_dir}/logfile_$counter &";
}
$script_string .= "fi\n\n";

//output to the browser
echo $script_string;
//Flush output cache
flush();