This function takes a (public) spreadsheet key and optionally sheet name and returns a clean 2-dimensional array of the table. Had to use CURL for my projects. You may use file_get_contents or fopen.

query_google_spreadsheets.php

<?php 
function query_google_spreadsheets( $key, $query, $sheet_name = '' ) {
	// queries a spreadsheet url and returns a clean array
	
	$sheet_url = 'https://spreadsheets.google.com/tq?key='. $key .'&tq='. $query .'&sheet='. $sheet_name;
	$str = file_get_contents( $sheet_url );
	
	// clean json string
	$str = str_replace( "// Data table response\ngoogle.visualization.Query.setResponse(", '', $str );
	$str = rtrim( $str, ');' );
	
	$str = json_decode( $str );
	
	// flatten array
	$arr = array();
	foreach ( $str->table->rows as $row ) :
		$new_row = array();
		foreach ( $row->c as $cell ) :
			$new_row[] = $cell->v;
		endforeach;
		$arr[] = $new_row;
	endforeach;
	
	return $arr;
} ?>