[%CFEngine_function_prototype(var)%]

Description: Returns whether a variable named var is defined.

The variable need only exist. This says nothing about its value. Use regcmp to check variable values. Variable references like foo[bar] are also checked, so this is a way to check if a classic CFEngine array or a data container has a specific key or element.

[%CFEngine_function_attributes(var)%]

Example:

[%CFEngine_include_snippet(isvariable.cf, #+begin_src cfengine3, .*end_src)%]

Output:

[%CFEngine_include_snippet(isvariable.cf, #+begin_src\s+example_output\s, .end_src)%]