MUSHclient documentation: Globalpreferences-Lua

Global preferences - Lua

Global preferences - Lua
Preliminary code You can enter some initial scripting that is executed every time that the Lua script engine is created. This can be used to set up a "sandbox", that is a safe environment for your scripts. The default behaviour is to disable the "os" library (operating system calls), which could be used to execute arbitrary commands, and rename or delete files. Also the "io" library is disabled, which could be used to read or overwrite existing files. To revert to the default settings, delete everything from this window, and then close and re-execute MUSHclient. Edit... Click to edit the code in a larger window. Allow DLLs to be loaded Check this to allow DLLs to be loaded by Lua code. Only check this if you are sure that you are not going to run untrusted scripts. We suggest that before checking "Allow DLLs to be loaded" you edit the "sandbox" code and disallow use of the package library except for trusted worlds or plugins. For example, enter these lines in the sandbox: `package.loadlib = nil --> disable loadlib function package.loaders [3] = nil --> disable DLL loader package.loaders [4] = nil --> disable all-in-one loader` The reason for the last two lines is that doing a "require" can trigger the DLL and all-in-one loaders, which are designed to load DLLs. See Also ... Topics Arrays Lua script extensions Plugins Scripting Scripting callbacks - MXP Scripting callbacks - plugins Scripting data types Scripting functions list Scripting return codes Utilities Variables World functions Dialog Global preferences - world lists and directories (Help topic: dialog=IDD_GLOBAL_PREFSP13) Documentation contents page

Preliminary code

You can enter some initial scripting that is executed every time that the Lua script engine is created. This can be used to set up a "sandbox", that is a safe environment for your scripts.

The default behaviour is to disable the "os" library (operating system calls), which could be used to execute arbitrary commands, and rename or delete files.

Also the "io" library is disabled, which could be used to read or overwrite existing files.

To revert to the default settings, delete everything from this window, and then close and re-execute MUSHclient.

Edit...

Click to edit the code in a larger window.

Allow DLLs to be loaded

Check this to allow DLLs to be loaded by Lua code.

Only check this if you are sure that you are not going to run untrusted scripts.

We suggest that before checking "Allow DLLs to be loaded" you edit the "sandbox" code and disallow use of the package library except for trusted worlds or plugins. For example, enter these lines in the sandbox:


package.loadlib = nil      --> disable loadlib function
package.loaders [3] = nil  --> disable DLL loader
package.loaders [4] = nil  --> disable all-in-one loader

The reason for the last two lines is that doing a "require" can trigger the DLL and all-in-one loaders, which are designed to load DLLs.

See Also ...

Topics

Arrays