Editing Engine:CCMD varedit

{{dev/uiccmd}}
Sets an existing variable in the current context, reports variable value.
<kua>bob fred</kua>

== Arguments ==
* name - name for variable to set
* value (optional) - the value to set. If no value, then prints value if exists.

== Associations ==
* Is the default command for the 'global' context.
* Does not have its own command name in 'global'.

== Details ==
Can be used to set or report a value for an existing variable. Will fail if variable does not already exist. In 'global' context, 'name' and 'value' are used directly in a statement with no command name. 

Behaves like a combination of 'var' and 'set', but will never create a variable:
* varedit - Never creates a variable, and sets anytime variable already exists.
* var - Will create and set a variable, only if the variable does not yet exist.
* set - Will create or set a variable, any time.

== Examples ==
=== Default values ===
<kua>
> bob
Unknown: bob
</kua>
No 'bob' in the context. Variable 'bob' doesn't exist, and 'bob' is not the name of anything else.

<kua>
> bob fred
Unknown: bob
</kua>
Tries to set variable 'bob' to 'fred'. Fails as 'bob' does not exist.

<kua>
> set bob fred
</kua>
Uses the 'set' command to create the variable 'bob' and set value to 'fred'.

<kua>
> bob
'bob' is 'fred'
</kua>
Same as the first example, but now 'bob' exists.

<kua>
> bob james
> bob
'bob' is 'james'
</kua>
Tries to set existing 'bob' to 'james', value changes.

=== Change if exists ===
In this example let's pretend 'bob' is a Client module variable. Client when started will create 'bob' with a default value in the 'global' context.
*  Variable 'bob' doesn't exist, and 'bob' is not the name of anything else.
<kua>
> bob
Unknown: bob
</kua>
* Tries to set variable 'bob' to 'fred'. Fails as 'bob' does not exist. Which is good.
<kua>
> bob fred
Unknown: bob
</kua>
* Using the 'client' context run the Client 'start' command which will create the variable 'bob' with a default value of '8080'. 
<kua>
> client start
</kua>
* Same as the first example, but now 'bob' exists.  
<kua>
> bob
'bob' is '8080'
</kua>
* Try to set existing 'bob' to '8081', value changes. 
<kua>
> bob 8081
> bob
'bob' is '8081'
</kua>
=== Macro ===
In this example 'bob' is still a Client module variable. We want to check the old value of bob before restarting the client. 

* Check the value of bob. Stop the service. Then start client and then change the value after started. Client was not started previously.
<kua>
> bob; client stop; client start; bob 8081; bob
Unknown: bob
Client not started.
Client started.
8081
</kua>
* Same but Client fails to start, and removed or did not yet create the variable 'bob' before returning.
<kua>
> bob; client stop; client start; bob 8081; bob
Unknown: bob
Client not started.
Client could not start.
Unknown: bob
Unknown: bob
</kua>

== Notes ==
* While 'varedit' is intended make console variable checking and editing easy, in combination with the other variable commands, can allow scripts and other types of macros to avoid lots of situations where complex logic would otherwise be required.
* This default command 'varedit' would allow writing a script that was intended to only set certain variables if another service or module had already created them.