Some operations for CSV in PHP

gistfile1.php

<?php

// Here's our multiline test CSV string:
$csv = <<<EOD
2012,Camel,1
2012,Marlboro,15
2013,Camel,15
2013,Marlboro,47
total,,78
EOD;

// Convert lines of CSV to a 2d array.
// Assumptions:
//   -- No new-line characters inside any fields.
//   -- Each line has the same number of fields.
function convert_csv_to_2d_array($csv) {
    $lines = explode("\n", $csv);
    $rv = array();

    foreach ($lines as $line) {
        $rv[] = str_getcsv($line);
    }

    return $rv;
}

// Usage:
$array = convert_csv_to_2d_array($csv);


// Rotate 2d array 90 degrees clockwise.
function rotate_2d_array($array) {
    $rv = array();
    foreach ($array as $rowkey => $row) {
        foreach($row as $colkey => $col){
            $rv[$colkey][$rowkey]=$col;
        }
    }
    return $rv;
}

// Usage:
$rotated_array = rotate_2d_array($array);

// Convert 2d array to CSV
function convert_2d_array_to_csv($array) {
    $fp = fopen('php://temp', 'r+');

    foreach ($array as $row) {
        fputcsv($fp, $row);
    }

    rewind($fp);
    $rv = '';
    while ( ($line = fgets($fp)) !== false ) {
        $rv .= $line;
    }
    return $rv;
}

// Usage:
$rotated_csv = convert_2d_array_to_csv($rotated_array);

echo $rotated_csv;
// 2012,2012,2013,2013,total
// Camel,Marlboro,Camel,Marlboro,
// 1,15,15,47,78