Crypt/GPG/Engine.php
public function setOperation($operation, array $arguments = array())
    {
        $this->_operation = $operation;
        $this->_arguments = $arguments;

        $this->_processHandler->setOperation($operation);
    }
public function setOperation($operation, array $arguments = array())
    {
        $this->_operation = $operation;
        $this->_arguments = $arguments;

        $this->_processHandler->setOperation($operation);
    }
Sets the operation to perform

@param string $operation the operation to perform. This should be one
of GPG's operations. For example,
<kbd>--encrypt</kbd>, <kbd>--decrypt</kbd>,
<kbd>--sign</kbd>, etc.
@param array  $arguments optional. Additional arguments for the GPG
subprocess. See the GPG manual for specific
values.

@return void

@see Crypt_GPG_Engine::reset()
@see Crypt_GPG_Engine::run()