ircII help: set shell_flags
Usage: SET SHELL_FLAGS <flags> Sets any additional flags that the shell (set with SET SHELL) might need. For most shells the -c flag is needed. This tells the shell to take the command line as a command to be parsed rather than a filename. The flag -f is also added sometimes, and with csh and tcsh this means to ignore the .cshrc file when a command is executed. This means aliases will not be available but the command will execute faster.