BASH rhymes, and also subversion problems.

Today I learned you can clear the BASH cache with hash.

Which is to say, BASH caches the full path to recently used commands, and sometimes that sucks. 

If you install a new copy of a program with the same name but in a different directory (earlier in the search path), BASH might incorrectly run the old version.  So, if you had svn in /usr/bin, and then installed a newer version in /opt/local/bin, you might end up pissed off.  Natch.

You can see the current cache:

$ hash
hits    command
  4    /sw/bin/which
 36    /usr/bin/svn
  3    /bin/rm
  1    /usr/bin/sudo
  1    /bin/mv
  1    /opt/local/bin/reset
  1    /sbin/ping
  2    /usr/bin/man
  1    /usr/bin/less
 23    /bin/ls
  2    /opt/local/bin/port
  5    /usr/bin/find

Or clear it:

$ hash -r

Or clear a single entry:

$ hash -d svn

Also: it rhymes.