Para generar un archivo txt con php

header("Content-Type: text/plain; charset=iso-8859-1");
header("Content-disposition:  attachment; filename=registros.txt");
header("Pragma: no-cache"); 
header("Expires: 0"); 

for($a=0;$a<count($rs);$a++){

$material = $maestra->getMaterialNum($rs[$a]['Serial_num']);

print($rs[$a]['Contract_num']);
print('|');
print($rs[$a]['Service_type']);
print('|');
print(formato_normal($rs[$a]['Purchase_date']) . " 0:00:00");
print('|');
print(formato_normal($rs[$a]['Validity_date']) . " 0:00:00");
print('|');
print($rs[$a]['E']);
print('|');
print(html_entity_decode($rs[$a]['Customer_name']));
print('|');
print($rs[$a]['G']);
print('|');
print($rs[$a]['H']);
print('|');
print($rs[$a]['Customer_email']);
print('|');
print(html_entity_decode($rs[$a]['Customer_address']));
print('|');
print($rs[$a]['Customer_cp']);
print('|');
print(html_entity_decode($rs[$a]['Custormer_city']));
print('|');
print(codigoProvincia($rs[$a]['Customer_cp']));
print('|');
print($rs[$a]['Customer_phone']);
print('|');
print($rs[$a]['Customer_fax']);
print('|');
print(html_entity_decode($rs[$a]['Reference_person']));
print('|');
print($rs[$a]['Location']);
print('|');
print($rs[$a]['R']);
print('|');
print($rs[$a]['S']);
print('|');
print($rs[$a]['T']);
print('|');
print($rs[$a]['U']);
print('|');
print($rs[$a]['V']);
print('|');
print($rs[$a]['W']);
print('|');
print($material); /////////
print('|');
print($rs[$a]['Serial_num']);
print('|');
print($rs[$a]['Options_list']);
print('|');
print($rs[$a]['Notes']);
print('|');
print($rs[$a]['AB']);
print('|');
print($rs[$a]['AC']);
print('|');
print($rs[$a]['AD']);
print('|');
print($rs[$a]['AE']);
print('|');
print($rs[$a]['AF']);
print('|');
print($rs[$a]['AG']);
print('|');
print($rs[$a]['H']);
print('|');
print($rs[$a]['AI']);
print('|');
print($rs[$a]['AJ']);
print('|');
print($rs[$a]['AK']);
print('|');
print($rs[$a]['Action']);
print('|');
print($rs[$a]['Country']);
print('|');
print($rs[$a]['AN']);

print "\r\n";

}