function fileLine($filePath, $string, $line, $mode = 'w') {
if (is_file ( $filePath )) {
$fileArr = file ( $filePath );
} else {
return '';
}
$size = count ( $fileArr );
if ($line > $size) {
return;
}
for($i = 0; $i < $size; $i ++) {
if ($i == $line - 1) {
switch (strtolower ( $mode )) {
case 'w' :
$newFileStr .= $string . "\r\n";
$newFileStr .= $fileArr [$i];
case 'u' :
$newFileStr .= $string . "\r\n";
case 'd' :
continue;
}
} else {
$newFileStr .= $fileArr [$i];
}
}
file_put_contents ( $filePath, $newFileStr );
return true;
}