Writing to a text file using Javascript

Question

I want to write to a text file using javascript. I know that it is possible but there are some problems.

I am running a javascript program that calculates the location of an object (its latitude & longitude) which changes every 5 seconds; i want to write this information to a text file. The javascript program will soon run on a server and I'll use the information written to the text file to communicate with an Android app on my phone.

So, my question really is:

1. How can it be done properly?
   
   I know that there may be some permission issues but considering it won't be online and available to others will it be a problem and, if it is, should I go with PHP to do what I want? I know ASP is more Microsoft orientated and I work with a Mac so PHP would be the preference here.

2. When writing a file, is it possible to write to an existing file or does the process simply destroy and recreate the same file?

• Ry-: So... node.js? Otherwise, JavaScript doesn't really run on the server.
• Hamish: javascript on the client side (browser) or server side (e.g. with node.js)?
• Quentin: I think you might want to clarify your question. If the JavaScript programme is running on the server then you'll need to be running a JS engine there (probably Node), which would remove the need for a second server side language (such as PHP or one that is ASP compatible)
• raphinesse: You should specify in which environment your JS is running. Browsers or server-side JS environments like node.js
• Quentin: If it isn't "online" then where is it? Are you planning a server-client app with both server and client running on a local network? Or is the entire thing running on the phone? (In which case, why is there a server involved?)

Answer 1

I would use PHP

http://www.php.net/

This has a good code example:

http://www.tizag.com/phpT/filewrite.php

Also, you can make the request using jQuery's AJAX function, this will allow to effectively run this code from javascript:

http://api.jquery.com/jQuery.ajax/

• Quentin: I'm of the opinion that the question is too unclear to say if PHP might be appropriate or not ... but even if it wasn't, this answer ignores most of the specific queries in it.
• SSH This: Duly noted, I added some further information, hopefully this will help

Answer 2

Using the latest HTML5 Javascript, you can use the FileSystem APIs to read/write/append to text files. This is a good tutorial here : Exploring the FileSystem APIs.

• Quentin: There's been no mention of HTML being involved. The question talks about a server and an Android application.