Is it possible to access local file via javascript? - javascript

if (window.ActiveXObject) {
try {
var fso = new ActiveXObject("Scripting.FileSystemObject");
fso.CopyFile("C:\\Program Files\\GM4IE\\scripts\\source.txt","C:\\Program Files\\GM4IE\\scripts\\target.txt", 1);
fso = null;
}
catch (e) {
alert (e.message);
}
}
I am getting error :
"Automation server can not create object" on the line where I am creating ActiveXObject instance.
I understand that it's considered very bad to access hard-drive data using javascript but I just need it.
I am using IE8 , Greasemonkey4IE to run my javascript.
Thank you,
Mohit
******************************
function WriteFile()
{
var fso = new ActiveXObject("Scripting.FileSystemObject");
fso.CopyFile("C:\\source.txt","C:\\target.txt", 1);
}
I've put the above code inside a simple HTML page and it worked perfect.
http://www.c-point.com/JavaScript/articles/file_access_with_JavaScript.htm
You can find the similar code on above mentioned location.
I modified it a bit, tough.
But when I am trying to run it through GreaseMonkey4IE it simply spitting the same error I specified earlier.
I did it guys, but thanks a lot for your quick and helpful replies.
All I did is :
Go to Tools > Internet options > Security > Custom Level
Under the ActiveX controls and plug-ins, select Enable for Initializing and Script ActiveX controls not marked as safe.

Using native JavaScript, no, it is not generally possible to access a local file. Using plugins and extensions like ActiveX, Flash, or Java you can get around this rule, generally with some difficulty.
For some browser and OS specific exceptions to this general rule, you might want to have a look here:
Local file access with javascript
Note that as of late 2012, the FileReader API has been supported in all major browsers and provides a native JavaScript mechanism for accessing local files that the user nominates (via an input element or by dropping them into the browser).
This still cannot be used to access an arbitrary file by name/path as in the examples in the original question.

HTML5 File API has multiple ways to access local files.
window.requestFileSystem allows you to request access to the filesystem. Browser support is very poor on this (Chrome only).
FileReader is the HTML5 FileReader API that allows you to programatically read files that users select through a <input type='file' /> Browser support is better on this.
You should use fallbacks like flash and POST to a server for full file access.
Generally reading arbitary files is considered "cheating the browser" so I you'll either have to use secure HTML5, ActiveX or Flash. All 3 of those require user permissions.

After some research I have found:
var fso = new ActiveXObject("Scripting.FileSystemObject");
//This line will create a xml file on local disk, C drive
fh = fso.CreateTextFile( "C:\\fileName.xml", true);
fh.WriteLine("this is going to be written in fileName.xml");
This is how we can do it.There are other methods also.
Accessing local file system is very bad thing to do but yes we can do it.
Automation server can not create object
To get rid of this error go to Tools → Internet Options → Security → select Internet icon → click Custom level → select Enable for Initialize and script ActiveX controls not marked as safe for scripting.
I have not tested this on any other berowser except IE8, but I am sure it will work.

Related

Save a file on the harddrive with javascript

I have the following problem:
We are currently using a script to export data from CAD assemblies. This script is running in the Creo browser, which is currently IE. To access the correct directory the following code is used:
var fso = new ActiveXObject("Scripting.FileSystemObject");
var f = fso.CreateTextFile(session.GetCurrentDirectory() + ComponentName + ".xml", true);
f.Write(iht.join("\n"));
f.Close();
The Creo bowser is going to be switched to Chrome. Because of this ActiveX is no longer going to work. Is there a way to archive the same result with different code in Chrome?
Creo is not supporting Chrome Plugins, so IE Tab is not an option.
Any help is greatly appreciated!!
There is a non-standard feature:
https://developer.mozilla.org/en-US/docs/Web/API/FileSystem
But again, it is non-standard.
Edit: as written in that link, "This interface will not grant you access to the users filesystem. Instead you will have a "virtual drive" within the browser sandbox."
No. No more ActiveX.
In the past, most (auto)CAD programs came with a builtin LISP editor you could write scripts in. Maybe that is usable to rewrite the export if you find a LISP programmer.
Myself, I would install node.js on a server so you can use their file system module, which is a good replacement for the old active x object. This probably will require you to copy the files to that server though, so your current workflow might change a bit.

Need help reading a file in Javascript located in the same directory

I've written this function to try and read a file located in the same directory as my Javascript files and index.html file. I've read from files before, but normally I have the user select the file themselves, so I've never had to create the actual file object.
Does anyone know why the code below doesn't work?
function getFile()
{
var reader=new FileReader();
var file=new File("input.txt");
var str=reader.result;
reader.readAsText(file);
return str;
}
Update:
Some additional information (My apologies if I don't answer your questions, I'm really new to this, and everything I know is self-taught).
Server side or client side? I think this it is going to be hosted serverside - I have a domain that I'm going to upload the file to.
Not possible due to security restrictions. You must use a file that was selected by a user. Imagine what would happen if javascript could read any file on your harddrive - nightmare!
I had a similar code for a desktop app written in JS. It worked well on IE and FF until Chrome came along (yes, it was a very long time ago!) and started restricting the sandbox ever more. At some point, IE and FF also tightened permissions and the method didn't work anymore (I used this code which does not work anymore):
try {
netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");
file = Components.classes["#mozilla.org/file/local;1"].createInstance(Components.interfaces.nsILocalFile);
file.initWithPath(filename);
if (file.exists())
{
inStream = Components.classes["#mozilla.org/network/file-input-stream;1"].createInstance(Components.interfaces.nsIFileInputStream);
inStream.init(file, 0x01, 00004, null);
sInStream = Components.classes["#mozilla.org/scriptableinputstream;1"].createInstance(Components.interfaces.nsIScriptableInputStream);
sInStream.init(inStream);
content = sInStream.read(sInStream.available());
}
} catch (ex) {
// and so on...
}
At some point FF and Chrome had some startup flags that enabled the sandbox to be lax on certain security restrictions, but in the end I realized that this is simply old code.
Today, I use localStorage to store data on the local machine. The only disadvantage is that you have to implement an import/export functionality so that it is portable to other browsers/machines by copy/paste the raw text.
What I do is simply this. The maximum size of the database is said to be about 10 MB (but deviations are known to exist) and all I store is a single JSON string:
function store(data)
{
localStorage.data = JSON.stringify(data);
}
function retrieve()
{
return JSON.parse(localStorage.data);
}
Obviously, these two functions are an oversimplification, you need to handle edge cases like when no data exists or a non-JSON string was imported. But I hope you get the idea on how to store local data on modern browsers.
With the File() constructor you can only create new file objects, but cannot read files from lokal disk.
It is not quite clear what exactly you want to achieve.
You say, that the input.txt is located in the same directory as your html and js. Therefore it is located on the server.
If you want to read a file from the server you have to use an ajax request which is already explained in anoter question.

how to read the file contents using javascript for ie8? [duplicate]

I've got a web page which needs to be able to load files into the DOM from the local machine on which the browser is running. I've found that this is very easy to do using the HTML 5 File API.
I can just do:
var reader = new FileReader();
reader.onload = function (fileContents) { ... load contents to a div ... }
reader.readAsText(f) //where f is an HTML5 File object
Annoyingly, I need this to work in IE7, and also some earlier versions of Firefox which don't support the API. Is there any easy way to load a local file into the DOM in older browsers?
Many thanks!
No, you cannot do that in older browsers. FileReader (any file system access really) is a new HTML5 feature which is not supported in older browsers.
Your best option in an older browser is either:
A Silverlight, Flash or Java app (or similar) that runs on the client-side and has local file system access.
Having the user upload files using the <input type="file"> element, and do your processing server-side.
Further to the other answers here, it does appear that there's no consistent way of doing this client-side (other than Flash) for older browsers.
For IE7/8 however, I've managed to hack something together using ActiveX.
var filePath = f:\oo.txt;
var fso = new ActiveXObject("Scripting.FileSystemObject");
var textStream = fso.OpenTextFile(filePath);
var fileData = file.ReadAll();
I can then pass this to the same function as reader.onload in the question above. Obviously this is a bad, hacky solution, and liable to be blocked by some security policies - it does at least work for IE7 though!
Looks like you can do that through Flash. Flash alternative for FileReader HTML 5 API

rename a file in javascript

i want to ask that if i want to rename a file in javascript, what can i do ? i have try a function which i see it online but cannot work.
function ChangeFileName()
{
var fso, f;
fso = new ActiveXObject("Scripting.FileSystemObject");
f = fso.GetFile("FilePath/MyFile.txt");
f.name = "MyFile.htm";
}
i search online and it says that the ActiveXObject is only available for IE and i intended to use it on mozilla because mozilla comes with ubuntu.
beside this, is there any method that i can rename a file inside the javascript ? thanks in advance for your help .
It is Javascript (in the browser), right?
If you run in the browser it is not allowed for security reasons. I think there is some way to do this using IE and ActiveX but using Pure Javascript I think it is not possible.
But you can do in JScript in the console, for example to delete a single file:
function MoveFile2Desktop(filespec)
{
var fso;
fso = new ActiveXObject("Scripting.FileSystemObject");
fso.MoveFile(filespec, "newname");
}
No, you cannot rename a file with javascript. Javascript is not able to interact with the user's computer in any way - it is only intended to be used to interact with the content of the web page it is rendered on.
JavaScript has no built in means to interact with a file system.
A host object might provide such a means.
The host object (window) that is available to JavaScript loaded from a web page in a typical web browser exposes no such object. Web pages are not allowed to edit the disks of people visiting their sites. (The exception is IE, with ActiveX, and some security warnings).
If you were running JavaScript in a browser extension or in a different environment (such as node.js) then it might be possible.

Javascript scope / security concern in Firefox extension

I am developing a FireFox extension and have to store some values that I need to be secure and inaccessible from any other extension/page etc.
I am using a setup for my extension code like seen here:
if(!namesp) var namesp={};
if(!namesp.anothernamesp) namesp.anothernamesp={};
namesp.anothernamesp = function() {
var mySecureValue = ''; //is this variable accessible from anything aside from inside the namesp.anothernamesp scope?
return {
useSecureValue: function() {
//do something here with mySecureValue
}
};
function getSecureValue() { //can this method be called from anywhere besides inside the namesp.anothernamesp scope?
return mySecureValue;
}
}();
Is there any way that anything other than my own extension can access "mySecureValue"? To keep this object global accessible to any windows I might open in my extension etc, I pass the object to the window in the window.openDialog() method and use the window.arguments to access it from the newly created windows. Thank you.
Seems pretty correct. In fact that's a way the majority of tutorials and books teach to simulate private methods and properties.
No, there is no way you can keep one extension from impacting another extension.
The reasons for that are:
extensions are Zip-archive-files renamed to have a *.xpi filename extension.
the extensions are writen in plaintextfiles using a JavaScript dialect
any other extension can at will open and access any file that your browser can access.
If some other extension wants to read your variable mySecureValue it can do so by:
accessing the your extensions *.xpi file (using nsIFile to read it from the profile/extensions folder)
unzip it nsIZipReader
read the variable mySecureValue from your source file!
The most unfortunate reason for all that is that Mozilla firefox does not implement any form of right separation between the extensions. Every extension can do everything to everybody. It can even excecute a shellcode and do arbitraty other damage.
The only thing you can try is to obfuscate your secret data. This will though not prevent but maybe only complicate the attack.

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