Rehash

rehash regenerates the system's cached info about what's contained in the system PATH. Commonly needed after installing new applications from the ports tree. Example:

ph34r# cd /usr/ports/net/rsync
ph34r# make install
ph34r# rsync --version
rsync: Command not found.
ph34r# rehash
ph34r# rsync --version
rsync  version 2.6.2  protocol version 28
Copyright (C) 1996-2004 by Andrew Tridgell and others
<http://rsync.samba.org/>
Capabilities: 64-bit files, socketpairs, hard links, symlinks, batchfiles,
              IPv6, 32-bit system inums, 64-bit internal inums

rsync comes with ABSOLUTELY NO WARRANTY.  This is free software, and you
are welcome to redistribute it under certain conditions.  See the GNU
General Public Licence for details.