The Plan 9 approach is to avoid creating problems for yourself by not using spaces in file names to begin with. The file server initially disallowed spaces in file names just as nulls and slashes are disallowed. That restriction has since been relaxed,† but everyone still avoids spaces. If you cannot avoid files with spaces in their names, there exists trfs,†† a file system that transparently replaces spaces with something more convenient.

Instead of find, I run /bin/test on a list of files. For anything more complicated than what test can handle, I use Inferno's fs program.†††

† http://swtch.com/cgi-bin/plan9history.cgi?f=1999/0323/port/c...

†† http://a-30.net/inferno/man/4/trfs.html

††† http://www.vitanuova.com/inferno/man/1/fs.html It has a misleading name. It is not a file server.