Download CSV and display in JSON

csv-json.php

<?php
/*
* @author       Andrew Van Tassel
* @email        andrew@andrewvantassel.com
* @notes        Create a data directory, Add tac param to start from end of file
* @todo         Add paging and offset param
*/
$_GET['limit']=isset($_GET['limit']) && is_numeric($_GET['limit'])?(int)$_GET['limit']:50;

function getFieldKeys($output){
                  $file = popen("head -1 $output", "r");
                  $keys = array();
                  if ($file) {
                      $buffer = fgets($file, 4096);
                      $line = explode(",", str_replace('"', '',$buffer));

                      //remove crlf on last key
                      $line[count($line)-1]=str_replace("\r\n", "", $line[count($line)-1]);
                      $keys=$line;
                  }
                  pclose($file);
                  return $keys;
                }

if(empty($_GET['file']))
  die('Need a file parameter with the URL of the CSV.');

$tac = isset($_GET['tac'])?true:false;

$csv_url_arr = explode("/", $_GET['file']);
$file_name = end($csv_url_arr);

$output = __DIR__.'/data/'.$file_name;
$csv_url = $_GET['file'];
$last_updated = date('Ymd');

$response = array('meta'=>array('file'=>$_GET['file'],'limit'=>$_GET['limit'],'tac'=>$tac),'data'=>array());

if(file_exists($output)){
        //set the date of last updated
        $last_updated=date('Ymd',filemtime($output));
        $response['meta']['last_updated']=$last_updated;
        if($last_updated != date('Ymd'))
                exec('mv '.$output.' '.str_replace('.csv', '-'.date('Ymd').'.csv', $output));
}

if($last_updated != date('Ymd') || !file_exists($output)){
        
        //exec('curl '.$csv_url.' > '.$output);
        
        set_time_limit(0);
        $fp = fopen ($output, 'w+');
        $ch = curl_init($csv_url);
        curl_setopt($ch, CURLOPT_TIMEOUT, 50);
        curl_setopt($ch, CURLOPT_FILE, $fp); // write curl response to file
        curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
        curl_exec($ch); // get curl response
        curl_close($ch);
        fclose($fp);
}

if(!file_exists($output)){
        die("CSV file not found, $output");
}

//$response['meta']['file']=$output;

$response['meta']['size']=round(filesize($output)/(1024 * 1024),2)."MB";

$totalLines = intval(exec("wc -l '$output'"));
$response['meta']['total']=!empty($totalLines)?($totalLines-1):0;

$keys = getFieldKeys($output);
$results=array();

if($tac)
  $handle = popen("tac $output", "r") or die("Couldn't get handle for $output");
else
  $handle = fopen("$output", "r") or die("Couldn't get handle for $output");

if ($handle) {

    while (!feof($handle)) {
        $buffer = fgets($handle, 4096);
        $line = explode(",", str_replace('"', '',$buffer));
        //remove crlf on last key
        $line[count($line)-1]=str_replace("\r\n", "", $line[count($line)-1]);

        //must have same number of elements
        if(count($keys) != count($line) || !$tac && $keys===$line)
          continue;

        $result=array_combine($keys,$line);

        $results[]=$result;

        if(count($results) == 50)
          break;
    }
    if($tac)
      pclose($handle);
    else
      fclose($handle);
}

$response['data']=$results;

header("Content-type: application/json");
echo json_encode($response);
?>