diff --git a/source/net/sourceforge/filebot/cli/ArgumentProcessor.java b/source/net/sourceforge/filebot/cli/ArgumentProcessor.java
index 66ab1485..d1359477 100644
--- a/source/net/sourceforge/filebot/cli/ArgumentProcessor.java
+++ b/source/net/sourceforge/filebot/cli/ArgumentProcessor.java
@@ -84,7 +84,7 @@ public class ArgumentProcessor {
 			} else {
 				// execute user script
 				Bindings bindings = new SimpleBindings();
-				bindings.put("args", args.getFiles(false));
+				bindings.put(ScriptShell.ARGV_BINDING_NAME, args.getFiles(false));
 
 				DefaultScriptProvider scriptProvider = new DefaultScriptProvider();
 				URI script = scriptProvider.getScriptLocation(args.script);
diff --git a/source/net/sourceforge/filebot/cli/ScriptShell.java b/source/net/sourceforge/filebot/cli/ScriptShell.java
index c53406a9..5178d9ae 100644
--- a/source/net/sourceforge/filebot/cli/ScriptShell.java
+++ b/source/net/sourceforge/filebot/cli/ScriptShell.java
@@ -2,7 +2,6 @@ package net.sourceforge.filebot.cli;
 
 import groovy.lang.GroovyClassLoader;
 
-import java.io.InputStreamReader;
 import java.net.URI;
 import java.util.Map;
 import java.util.ResourceBundle;
@@ -11,9 +10,6 @@ import javax.script.Bindings;
 import javax.script.ScriptContext;
 import javax.script.ScriptEngine;
 import javax.script.ScriptException;
-import javax.script.SimpleScriptContext;
-
-import net.sourceforge.filebot.format.ExpressionFormat;
 
 import org.codehaus.groovy.control.CompilerConfiguration;
 import org.codehaus.groovy.control.customizers.ImportCustomizer;
@@ -22,6 +18,9 @@ import org.codehaus.groovy.runtime.StackTraceUtils;
 
 public class ScriptShell {
 
+	public static final String ARGV_BINDING_NAME = "args";
+	public static final String SHELL_BINDING_NAME = "__shell";
+
 	private final ScriptEngine engine;
 	private final ScriptProvider scriptProvider;
 
@@ -34,19 +33,10 @@ public class ScriptShell {
 		bindings.putAll(globals);
 
 		// bind API objects
-		// TODO remove
-		bindings.put("_cli", new CmdlineOperations());
-		bindings.put("_shell", this);
+		bindings.put(SHELL_BINDING_NAME, this);
 
 		// setup script context
-		ScriptContext context = new SimpleScriptContext();
-		context.setBindings(bindings, ScriptContext.GLOBAL_SCOPE);
-		engine.setContext(context);
-
-		// import additional functions into the shell environment
-		// TODO remove
-		engine.eval(new InputStreamReader(ExpressionFormat.class.getResourceAsStream("ExpressionFormat.lib.groovy")));
-		engine.eval(new InputStreamReader(ScriptShell.class.getResourceAsStream("ScriptShell.lib.groovy")));
+		engine.getContext().setBindings(bindings, ScriptContext.GLOBAL_SCOPE);
 	}
 
 	public ScriptEngine createScriptEngine() {
diff --git a/source/net/sourceforge/filebot/cli/ScriptShell.properties b/source/net/sourceforge/filebot/cli/ScriptShell.properties
index 7c3487e6..fb340425 100644
--- a/source/net/sourceforge/filebot/cli/ScriptShell.properties
+++ b/source/net/sourceforge/filebot/cli/ScriptShell.properties
@@ -1,3 +1,3 @@
 scriptBaseClass: net.sourceforge.filebot.cli.ScriptShellBaseClass
 starImport: net.sourceforge.filebot, net.sourceforge.filebot.hash, net.sourceforge.filebot.media, net.sourceforge.filebot.mediainfo, net.sourceforge.filebot.similarity, net.sourceforge.filebot.subtitle, net.sourceforge.filebot.torrent, net.sourceforge.filebot.web, net.sourceforge.filebot.util, groovy.io, groovy.xml, groovy.json, org.jsoup, java.nio.file, java.nio.file.attribute, java.util.regex
-starStaticImport: net.sourceforge.filebot.WebServices, java.nio.file.Files
\ No newline at end of file
+starStaticImport: net.sourceforge.filebot.format.ExpressionFormatFunctions, net.sourceforge.filebot.WebServices, java.nio.file.Files
diff --git a/source/net/sourceforge/filebot/cli/ScriptShellBaseClass.java b/source/net/sourceforge/filebot/cli/ScriptShellBaseClass.java
index ea5d949b..8f5064d3 100644
--- a/source/net/sourceforge/filebot/cli/ScriptShellBaseClass.java
+++ b/source/net/sourceforge/filebot/cli/ScriptShellBaseClass.java
@@ -1,14 +1,23 @@
 package net.sourceforge.filebot.cli;
 
+import static java.util.Collections.*;
 import static net.sourceforge.filebot.Settings.*;
 import static net.sourceforge.filebot.cli.CLILogging.*;
 import groovy.lang.Closure;
+import groovy.lang.MissingPropertyException;
 import groovy.lang.Script;
 
 import java.io.Console;
+import java.io.File;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Map;
 import java.util.logging.Logger;
 
+import javax.script.Bindings;
+import javax.script.SimpleBindings;
+
 import net.sourceforge.filebot.MediaTypes;
 import net.sourceforge.filebot.format.AssociativeScriptObject;
 
@@ -18,10 +27,56 @@ public abstract class ScriptShellBaseClass extends Script {
 		System.out.println(this);
 	}
 
-	public Object _guarded(Closure<?> c) {
+	public Object executeScript(String input, Map<String, ?> bindings, Object... args) throws Throwable {
+		// apply parent script defines
+		Bindings parameters = new SimpleBindings();
+
+		// initialize default parameter
+		parameters.putAll(bindings);
+		parameters.put(ScriptShell.ARGV_BINDING_NAME, asFileList(args));
+
+		// run given script
+		ScriptShell shell = (ScriptShell) getBinding().getVariable(ScriptShell.SHELL_BINDING_NAME);
+		return shell.runScript(input, parameters);
+	}
+
+	private Map<String, ?> defaultValues;
+
+	public void setDefaultValues(Map<String, ?> values) {
+		this.defaultValues = values;
+	}
+
+	public Map<String, ?> getDefaultValues() {
+		return defaultValues == null ? null : unmodifiableMap(defaultValues);
+	}
+
+	@Override
+	public Object getProperty(String property) {
+		try {
+			return super.getProperty(property);
+		} catch (MissingPropertyException e) {
+			// try user-defined default values
+			if (defaultValues != null && defaultValues.containsKey(property)) {
+				return defaultValues.get(property);
+			}
+
+			// can't use default value, rethrow exception
+			throw e;
+		}
+	}
+
+	public Object tryQuietly(Closure<?> c) {
 		try {
 			return c.call();
-		} catch (Throwable e) {
+		} catch (Exception e) {
+			return null;
+		}
+	}
+
+	public Object tryLoudly(Closure<?> c) {
+		try {
+			return c.call();
+		} catch (Exception e) {
 			CLILogger.severe(String.format("%s: %s", e.getClass().getSimpleName(), e.getMessage()));
 			return null;
 		}
@@ -67,4 +122,18 @@ public abstract class ScriptShellBaseClass extends Script {
 		return System.console();
 	}
 
+	public static List<File> asFileList(Object... paths) {
+		List<File> files = new ArrayList<File>();
+		for (Object it : paths) {
+			if (it instanceof CharSequence) {
+				files.add(new File(it.toString()));
+			} else if (it instanceof File) {
+				files.add((File) it);
+			} else if (it instanceof Path) {
+				files.add(((Path) it).toFile());
+			}
+		}
+		return files;
+	}
+
 }