Files
sics/doc/manager/alias.htm

66 lines
2.4 KiB
HTML

<HTML>
<HEAD>
<TITLE>Aliases in SICS</TITLE>
</HEAD>
<BODY>
<H1>Aliases in SICS</H1>
<P>
SICS knows three different kinds of aliases: object aliases,
runtime aliases and command
aliases. This is confusing but finds its explanation in the structure
of SICS internals.
</P>
<h2>Object Aliases</h2>
<p>
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:
<DL>
<DT>SicsAlias oldname newname
<DD>This command installs newname as alias for the object oldname.
</dl>
SicsAlias can only be used within initialization scripts. SicsAlias is
considered deprecated and can be replaced with the superior runtime
aliases described below.
</p>
<h2>Runtime Aliases</h2>
<p>
Runtime aliases are full object aliases which can be configured into the
system at run time by a SICS manager.
The syntax looks like this:
<dl>
<dt>DefineAlias aliasname SICSobject
<dd>This defines aliasname to be the alias for the SICS object SICSobject.
It is not needed that SICSobject already exists. If SICSobject is already
an alias, it is translated before definition.
Multiple translation is possible, depending on the order of definition.
When an alias is used, and it does not point to an existing object,
the behaviour is the same as if an unknown object would have been used.
<dt>DefineAlias aliasname
<dd>This command deletes the alias aliasname.
</dl>
</p>
<h2>Command Aliases</h2>
<p>
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:
<DL>
<DT>alias shortcut bla bla bla ....
<DD>This define shortcut as an alias for everything behind it.
</DL>
A shortcut may take parameters.
</p>
</BODY>
</HTML>