Use the -c option when you want to execute a single mpadmin command and return automatically to the shell prompt. For example, the following use of mpadmin -c changes the location of the CRE log file to /home/wmitty/cre_messages:
# mpadmin -c set logfile="/home/wmitty/cre_messages"
Most commands that are available via the interactive interface can be invoked via the -c option. See "mpadmin Command Overview" for an overview of the mpadmin command set and a list of which commands can be used as arguments to the -c option.