| #### Command Processing The DCE control program supports the Tcl built-in commands as well as its own commands. If a command name is unknown to dcecp, it is passed to the unknown command and dcecp evaluates it using the following algorithm: · If the command is found in a dcecp script file, dcecp executes the command. · If the command exists as an executable UNIX program, dcecp executes the command. Therefore, you can invoke any UNIX command from the dcecp prompt (for example, ls -l). Because you do not leave dcecp, you do not lose any context you have established. · If you have invoked the command at the top level of the dcecp shell and the command requests c-shell-like history substitution (such as, !!, !<number> or ^old^new), dcecp emulates the c-shell's history substitution. · If you have invoked the command at the top level of the dcecp shell and the command is a unique abbreviation for another command, dcecp invokes the command. ####