read/write Windows image tags (keywords)

Question

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How can I read/write these tags from a file on Windows?

I'm trying to acheive it in javascript and node.js but failed to find information in any language at all so I'm looking for any clues.

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The word tags (sometimes called keywords) seem to be unfortunately chosen, as it appears to be normally describing any metadata of a file, such as EXIF. Yet in windows you can save such descriptive-tags as one of the file tags. To start with - any idea on how are they really called?

I'm aware you can modify them using various programs, eg. in Adobe Bridge they're called keywords of a file.

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Note: I do realise it's not the best solution of storing file tags. I really just need to work with these, since the image library I'm working with is using them heavily.

[Edit.1]

@Ben Fortune: Thanks for the clue! Still, Exif-parser gives a way to read these tags, however does not allow for writing.

Answer 1

And the answers are:

1. These Windows tags are really called EXIF XPKeywords. See the full list here

2. Parsing a file using Exif Parser is good for reading, however they come back as decimal ASCII code. Using

   String.fromCharCode()
   

   and looping through the returned integers I managed to get the tags as strings.

3. However, for reading AND writing I ended up going with the exiftool. Therefore, I'm using

   function run_cmd(cmd, args, callBack ) {
       var spawn = require('child_process').spawn;
       var child = spawn(cmd, args);
       var resp = "";
   
       child.stdout.on('data', function (buffer) { resp += buffer.toString() });
       child.stdout.on('end', function() { callBack (resp) });
   } // ()
   

   to execute the exiftool as a shell command (More on spawning shell command)

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For reading I'm passing

    run_cmd('exiftool', ['-XPKeywords', myFilepath])

to read the XPKeywords tag and

    theShellResult.match(/:(.*)/)

to filter out only the keywords (Nicely explained here).

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For writing (appending) new XPKeywords I'm simply changing the args to:

    var writeArg = "-XPKeywords<$XPKeywords " + myNewKeywords
    run_cmd('exiftool', [writeArg, myFilepath])

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I found a way around it but I'd be calm knowing it is not executed through a shell command. Therefore, the question remains open - Can you suggest a good the interface for reading and writing EXIF tags in node.js?