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Erlang Run-Time System Application (ERTS)
Reference Manual
Version 5.10.1

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# werl

### COMMAND

werl

### COMMAND SUMMARY

The Erlang Emulator

### DESCRIPTION

On Windows, the preferred way to start the Erlang system for interactive use is:

werl <arguments>

This will start Erlang in its own window, with fully functioning command-line editing and scrollbars. All flags except -oldshell work as they do for the erl command.

Ctrl-C is reserved for copying text to the clipboard (Ctrl-V to paste). To interrupt the runtime system or the shell process (depending on what has been specified with the +B system flag), you should use Ctrl-Break.

In cases where you want to redirect standard input and/or standard output or use Erlang in a pipeline, the werl is not suitable, and the erl program should be used instead.

The werl window is in many ways modelled after the xterm window present on other platforms, as the xterm model fits well with line oriented command based interaction. This means that selecting text is line oriented rather than rectangle oriented.

To select text in the werl window , simply press and hold the left mouse button and drag the mouse over the text you want to select. If the selection crosses line boundaries, the selected text will consist of complete lines where applicable (just like in a word processor). To select more text than fits in the window, start by selecting a small portion in the beginning of the text you want, then use the scrollbar to view the end of the desired selection, point to it and press the right mouse-button. The whole area between your first selection and the point where you right-clicked will be included in the selection.

The selected text is copied to the clipboard by either pressing Ctrl-C, using the menu or pressing the copy button in the toolbar.

Pasted text is always inserted at the current prompt position and will be interpreted by Erlang as usual keyboard input.

Previous command lines can be retrieved by pressing the Up arrow or by pressing Ctrl-P. There is also a drop down box in the toolbar containing the command history. Selecting a command in the drop down box will insert it at the prompt, just as if you used the keyboard to retrieve the command.

Closing the werl window will stop the Erlang emulator.