include "newns.m";
ns := load Newns Newns->PATH;

newns:   fn(user: string, nsfile: string): string;
newuser: fn(user: string, cap: string, nsfile: string): string;

Newuser uses a capability cap suitable for cap(3) to change the current process's user name to user, and uses newns and nsfile to build it a new name space. The capability is typically obtained via factotum(4).