-arp() { cat /proc/net/arp; }
-ldd() { LD_TRACE_LOADED_OBJECTS=1 $*; }
-reboot() { ifdown wan 2>&1 >/dev/null ; /sbin/reboot; }
+[ -z "$KSH_VERSION" -o \! -s /etc/mkshrc ] || . /etc/mkshrc
+
+[ -x /sbin/arp ] || arp() { cat /proc/net/arp; }
+[ -z /bin/ldd ] || ldd() { LD_TRACE_LOADED_OBJECTS=1 $*; }