Get all the fonts used in text layers in all open documents and save them to a target txt file, one at a line.

PhotoshopGetUsedFonts.jsx

/**
* 
*
* Modified version of text export script (https://github.com/omgmog/photoshop-text-export) 1.3
* Used to export the used fonts in all open photoshop documents
*
**/
  

	// Use save as dialog (true/false)? - This will be overriden to false when running TextExport on multiple files!
	var useDialog	= true;
	// Open file when done (true/false)? - This will be overriden to true when running TextExport on multiple files!
	var openFile	= true;
	// text separator
	var separator	= "*************************************";

	var used_fonts = new Array();
 /**
  * NO NEED TO CHANGE ANYTHING BENEATH THIS LINE
  * -------------------------------------------------------------
  */
	/**
	 *  TextExport Init function
	 * -------------------------------------------------------------
	 */
	 	function initTextExport() {
			// Linefeed shizzle
			if ($.os.search(/windows/i) != -1)
				fileLineFeed = "windows";
			else
				fileLineFeed = "macintosh";
			// Do we have a document open?
			if (app.documents.length < 1) {
				alert("Please open at least one file", "TextExport Error", true);
				return;
			}
			// Oh, we have more than one document open!
			if (app.documents.length > 1) {
				var runMultiple = confirm("TextExport has detected Multiple Files.\nDo you wish to run TextExport on all opened files?", true, "TextExport");
				if (runMultiple === true) {
					docs = app.documents;					
				} else {				
					docs = [app.activeDocument];
				}
			} else {
				runMultiple 	= false;
				docs 		= [app.activeDocument];
			}

			// Pop up save dialog
			var saveFile = File.saveDialog("Please select a file to export the text to:");
			// User Cancelled
			if(saveFile == null)
			{
				alert("User Cancelled");
				return;
			}

			// set filePath and fileName to the one chosen in the dialog
			filePath = saveFile.path + "/" + saveFile.name;
			var fileOut	= File(filePath);
			// clear dummyFile
			dummyFile = null;
			// set linefeed
			fileOut.linefeed = fileLineFeed;
			// open for write
			fileOut.open("w", "TEXT", "????");
			// Loop all documents
			for (var i = 0; i < docs.length; i++)
			{
				// create outfile
				

				// Append title of document to file
				// Set active document
				app.activeDocument = docs[i];
				// call to the core with the current document
				goTextExport2(app.activeDocument, fileOut, '/');
				//  Hammertime!
				// close the file
				
				// Give notice that we're done or open the file (only when running 1 file!)
				if (runMultiple === false)
				{
					if (openFile === true)
						fileOut.execute();
					else
						alert("File was saved to:\n" + Folder.decode(filePath), "TextExport");
				}
			}
			fileOut.close();
			if (runMultiple === true)
			{
				alert("Parsed " + documents.length + " files;\nFiles were saved in your documents folder", "TextExport");
			}
		}
  	/**
  	 * TextExport Core Function (V2)
  	 * -------------------------------------------------------------
	 */
		function goTextExport2(el, fileOut, path) 
		{
			// Get the layers
			var layers = el.layers;
			// Loop 'm
			for (var layerIndex = layers.length; layerIndex > 0; layerIndex--)
			{
				// curentLayer ref
				var currentLayer = layers[layerIndex-1];
				// currentLayer is a LayerSet
				if (currentLayer.typename == "LayerSet") {
					goTextExport2(currentLayer, fileOut, path + currentLayer.name + '/');
				// currentLayer is not a LayerSet
				} else {
					// Layer is visible and Text --> we can haz copy paste!
					if ( (currentLayer.visible) && (currentLayer.kind == LayerKind.TEXT) )
					{
						if (ProcessFont(currentLayer.textItem.font)) {
							fileOut.writeln(currentLayer.textItem.font);
						};

					}
				}
			}
		}

		function ProcessFont(font) 
		{
			for (var i = used_fonts.length - 1; i >= 0; i--) {
				if (used_fonts[i] == font)
				{
					return false;
				}
			};

			used_fonts.push(font);
			return true;
		}
	/**
	 *  TextExport Boot her up
	 * -------------------------------------------------------------
	 */
	 	initTextExport();