I avoid situations where arbitrary characters have to be quoted. In the rare case where I have a CGI form that accepts something like a filename, I'll reject the name if it contains any funny characters. Trying to escape funny characters is a losing battle.

I also keep my filenames simple (using only alphanumerics, underscores, dashes, and periods).

Alas, I do not have the luxury of making up my own filenames.

I am working on a "utility" type program executed from crontab rather than as a CGI, and my filenames come from walking a directory tree. The files might be generated by anything, and I want to cover all the bases.

Trying to escape funny characters is a losing battle.

Well... sort-of. Not a problem when doing straight open's, or simple system's (systen with a list of arguments avoids the shell).

When launching a "pipeline" of several external programs, the shell provides tremendous convenience... see original post.