Run commands in restricted environments

 Chrootuid makes it easy to run a network service at low privilege
 level and with restricted file system access. The daemons have access only
 to their own directory tree, and run under a low-privileged userid.
 .
 In the past it has been used to run the gopher and www
 (world-wide web) network. It can be used nowadays also for proxy servers.
 The arrangement greatly reduces the impact of possible loopholes in
 network software.