This is extension for Gecko-based applications (Firefox, Thunderbird, SeaMonkey), for developers and testers.
Adds ability to write certain console messages to log files, see defaults/preferences/prefs.js for technical details.

---

Examples

All errors (+warnings) and all messages:

// Console Logger options
{
	"All_errors": {
		"enabled": true,
		"source": "^",
		"message": "",
		"exclude": ""
	},
	"All_messages": {
		"enabled": true,
		"source": "",
		"message": "^",
		"exclude": ""
	}
}

Options example for Private Tab extension:

// Console Logger options
{
	"Private_Tab": {
		"enabled": true,
		"source": "^chrome://privatetab/|/privateTab@infocatcher",
		"message": "",
		"exclude": "^unsafe CPOW usage|^Only internal code is allowed to set the usePrivateBrowsing attribute"
	},
	"Private_Tab_messages": {
		"enabled": false,
		"source": "",
		"message": "^\\[Private Tab\\]",
		"exclude": ""
	}
}

(use Options – Paste to import)

---

API

You can use Custom Buttons or something similar to open options from toolbar button.
Code:

var obs = "Services" in window && Services.obs
	|| Components.classes["@mozilla.org/observer-service;1"]
		.getService(Components.interfaces.nsIObserverService);
var scope = {};
scope.wrappedJSObject = scope;
obs.notifyObservers(scope, "consoleLogger-exportScope", null);
scope.consoleLogger.openOptions();

Also available consoleLogger.openOptionsInWindow() and consoleLogger.openOptionsInTab() API to force open options in window or tab.
Icon: chrome://consolelogger/content/icon16.png