# Embedded functions

There are several internal Opus commands that can cause a new Lister or tab to be opened - the most commonly used of these is **Go NEW** and **Go NEWTAB**. Sometimes, you might want a button or hotkey that opens a new Lister (or tab), and then executes further commands in the context of that new element. This can be achieved quite simply by embedding a function that will be passed to the new element once it has been created.

The embedded function must be surrounded with square brackets - for example, the following command would open a new Lister and put it into thumbnails mode automatically:

```
Go /mypictures NEW
[Set VIEW=thumbnails]
```

More complicated multiple line functions can also be embedded, for example:

```
Go NEW
[
Go /mypictures
Set VIEW=thumbnails
]
```

Additionally, functions can be embedded in a **Go FINDTITLE** command. These functions will be run in **all** existing Listers that match the supplied string. If no matching Listers are found, by default the embedded command will not be run at all - you can use the **RUNEMBEDDEDIFNOTFOUND** argument to cause the function to be run in the current Lister in this situation.

You can also embed functions in several [dynamic button](editing_the_toolbar/dynamic_buttons) commands - for example, **Go DRIVEBUTTONS**. This lets you define a command that is added to each of the buttons generated by the function. For example,

```
Go DRIVEBUTTONS OPENINLEFT
[
Set FOCUS=Left
]
```

This command would produce drive buttons that open their folders in the left-hand file display, and automatically set the focus to that file display at the same time.

The full list of commands that currently support embedded functions are:

* **Favorites** (dynamic button command)
* **Go NEW**
* **Go NEWTAB**
* **Go FINDTITLE**
* **Go DRIVEBUTTONS** (dynamic button command)
* **Go FTPSITELIST** (dynamic button command)
* **Go FOLDERCONTENT** (dynamic button command)
* **Prefs LAYOUT**
* **Properties SETLABEL** (dynamic button command)
* **Recent** (dynamic button command)
* **Show**
