# Aliases in SICS

SICS knows two different kinds of aliases: object aliases and command aliases. This is confusing but finds its explanation in the structure of SICS internals.

## Object Aliases

An object alias is another name for a first class object installed into the SICS interpreter. For instance a second name for a motor. For instance the motor twotheta is quite often aliased to a4. Such an alias can be used like a normal SICS objects. Even in commands which access internal SICS interfaces like the drive command or others. Object aliases are installed into SICS with the SICSAlias command:

SicsAlias newname oldname
  This command installs newname as alias for the object oldname.

SicsAlias can only be used within initialization scripts.

## Command Aliases

Command aliases are shortcuts for lengthy commands. For instance one might want to define A4LL as a shortcut for "a4 softlowerlim". This is just to save typing or adapt SICS to MAD users who appear to have an unlimited memory for 2-4 letter acronyms. It is possible to redefine a SICS object with this for instance to define tt as an alias for temperature. However if one tries to use tt in a drive command it will fail because it is just a text replacement. A command alias can be installed into SICS at any time with manager privilege and the command:

alias shortcut bla bla bla ....
  This define shortcut as an alias for everything behind it.

A shortcut may take parameters.