#!/usr/bin/node
//
//
//
//
// data_collector_cgi source
//
//
//
//
// <![CDATA[
//
// File: data_collector_cgi
//
// Author: Francesco.Prelz@mi.infn.it
//
// Description: Sample CGI program built with server-side Javascript
// (node.js) that forks a background network listener that collects data
// and serves such data in JSON format to web clients.
//
// History:
// 6-Oct-2014 Initial creation.
// 10-Oct-2012 Moved away from node-cgi module.
var fs = require('fs');
var path = require('path');
var childp = require('child_process');
var myself = path.basename(process.argv[1], ".nd");
var pidfile = "/var/tmp/" + myself + ".pid";
var xmldata = "/var/tmp/" + myself + "_data.xml";
var need_to_start_child = true;
var child_pid;
try
{
child_pid = fs.readFileSync(pidfile, "utf8");
child_pid = child_pid.replace(/[^0-9]*$/, '');
}
catch (err)
{
child_pid = "";
}
if (parseInt(child_pid, 10) > 0)
{
var child_in_proc = "/proc/"+child_pid;
if (fs.existsSync(child_in_proc)) need_to_start_child = false;
}
if (need_to_start_child)
{
var child = childp.spawn("/home/guest/public_html/esercizi/wireless/jsFiles/data_collector_process", [ pidfile, xmldata ],
{
detached: true,
stdio: [ 'ignore', 'ignore', 'ignore' ]
});
child.unref();
}
fs.exists(xmldata, function (file_exists)
{
process.stdout.write("Content-type: text/xml\n\n");
if (file_exists)
{
fs.createReadStream(xmldata).pipe(process.stdout);
}
else
{
process.stdout.write("<dataBlocks></dataBlocks>\n");
}
});
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