[MacPerl] checking for illegal characters in file name

[Katherine Richmond]

Well now that I have my file names, I have to make sure they contain only word
characters. I am also allowing periods. I can easily detect if I don't have a
legal word character, but how do I say, 'except for a period' ? This is what I
am doing now:

if ($fileName =~ /\W+/) {

   # report an error

}

Thanks,
Kathy