MirBSD Korn shell
-c string  mksh will execute the command(s) contained in string.
-i         Interactive shell.  A shell is “interactive” if this option is used or if both standard input
           and standard error are attached to a tty(4).  An interactive shell has job control enabled,
           ignores the SIGINT, SIGQUIT, and SIGTERM signals, and prints prompts before reading input (see
           the PS1 and PS2 parameters).  It also processes the ENV parameter or the mkshrc file (see
           below).  For non-interactive shells, the trackall option is on by default (see the set command
source manpages: mksh