## Referencing operating system / Java system variables

All configuration files support the definition of references to operating system and Java variables.

### Operating system vairables

In all operating system you can define variables.

Example (Windows):

set xyzValue=c:\temp
catalina jpda run

Inside the configuration file you can reference this value by the expression "${env.xyzValue}".

Example:

...
...directory="${env.xyzValue}/log/cc/"...
...

### Java variables

These are the ones passed as "-D" parameters when calling java.exe.

Example (Windows):

set JAVA_OPTS=-Xmx1000m -Xms128m -DxyzValue=C:\temp
catalina jpda run

Inside the configuration file you can reference this value by the expression "${sys.xyzValue}".

Example:

...
...directory="${sys.xyzValue}/log/cc/"...
...

### Web application context

Inside the configuration file you can reference the current web context name with the expression "${webappName}". If the application is running directly as root context then the value returned is "root".