Excellent article. The quick summary ([1]) is particulary good.
Note that quoting variable names is a good idea for other reasons, e.g., when a variable unexpectedly ends up empty: Not quoting such a variable can lead to termination in calls to test ([ ]), e.g., because the empty variable is replace with nothing (so that test sees the next non-whitespace token instead of the expected variable value, empty or otherwise), while quoting will at least cause the shell to correctly replace the variable with an empty string.
Comments
Excellent article. The quick summary ([1]) is particulary good.
Note that quoting variable names is a good idea for other reasons, e.g., when a variable unexpectedly ends up empty: Not quoting such a variable can lead to termination in calls to test ([ ]), e.g., because the empty variable is replace with nothing (so that test sees the next non-whitespace token instead of the expected variable value, empty or otherwise), while quoting will at least cause the shell to correctly replace the variable with an empty string.
[1] http://www.dwheeler.com/essays/filenames-in-shell.html#summa...