perl -MYAPE::Regex::Explain -e " print YAPE::Regex::Explain->new(qr/$ARGV[0]/)->explain();" "[^\s\*=]"
..
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  [^\s\*=]                 any character except: whitespace (\n, \r,
                           \t, \f, and " "), '\*', '='
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perl -MYAPE::Regex::Explain -e " print YAPE::Regex::Explain->new(qr/$ARGV[0]/)->explain();" "\w"
..
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  \w                       word characters (a-z, A-Z, 0-9, _)
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