For a long time now, I've been writing scripts that handle filenames both with and without spaces. You've got to know your shell and how Posix commands work! Commonly, I want to list files in a directory and do things to them whether or not they have spaces in them.
Shell patterns such as "*" break strings into "words" based on whitespace (spaces, tabs, newlines). This stuffs up a filename if its has spaces in it, since the name then gets split into separate words. But commands such as "ls" (when not directed to a terminal) list each filename on a separate line. So if you have something that distinguishes between spaces/tabs and newlines then you can get complete filenames with or without spaces.
The shell command "read" reads a line and breaks it into words. so
read a b cwith input
a line of text
will read all of the line into the variable. It stops reading on end-of-line so it has the distinction type I often need.
But how to use it? Well, the shell while loop is just a simple command, and as such can have its I/O redirected. So I do this:
while read filename
#process filename e.g.
cp "$filename" ~/backups
This works for all files, with or without spaces. Just don't forget the quotes while processing the file!
Of course, this doesn't work for all uses: note the find and xargs combination that Dave also commented on:
find . -print0 | xargs -0 ...