An apparatus for predicting a command in a command line interface includes a template command module, a parameter derivation module, and a parameter substitution module. The template command module is configured to determine a template command based on a command line history. The template command includes a command name and a parameter and the command line history includes two or more previously entered commands. The parameter derivation module is configured to determine a parameter derivation rule for deriving the parameter in the template command based on the command line history. The parameter substitution module is configured to substitute a substitute parameter for the parameter of the template command according to the parameter derivation rule.