改行をBRタグに置き換える
Posted feedbacks - Ruby
これ難しいですねえ。 あらゆる入力に対して大丈夫かは自信がもてません。
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 | require 'cgi'
def div(s, reg)
return [s] if s !~ reg
($` != "" ? [$`] : []) + [$&] + div($', reg)
end
def quo(state, r, sym)
case state.last
when sym
state.pop
state.slice!(-2, 2) if state[-2,2] == [:hrf, :eql]
r
when :atr then ""
else
state.push(sym)
r
end
end
def tag(state, r, sym, s)
case state.last
when :sgl, :dbl then "<#{s}"
else
state.push(sym)
state.push(:atr)
r
end
end
def kak(state, r)
case state.last
when :sgl, :dbl
if state[-2] == :eql && state[-3] == :hrf
CGI.escape(r)
else
CGI.escapeHTML(r)
end
else
CGI.escapeHTML(r)
end
end
def filter(s)
state = [:nml]
div(s, %r{(<a|<br|<strong|</|<|>|=|&|\"|\'|\n)}i).map{|r|
case r
when /'/ then quo(state, r, :sgl)
when /"/ then quo(state, r, :dbl)
when /<a/i then tag(state, r, :a, "a")
when /<br/i then tag(state, r, :br, "br")
when /<strong/i then tag(state, r, :str, "strong")
when /<\//
case state.last
when :a, :br, :str then state[-1] = :cls; r
else "</"
end
when /</
kak(state, r)
when />/
case state.last
when :atr then state.pop; (state.last==:br ? "/" : "") + r
when :cls, :hrf, :eql then state.pop; r
else kak(state, r)
end
when /href/i
case state.last
when :atr then state[-2] == :a ? (state.push(:hrf); r) : ""
else r
end
when /name/i
case state.last
when :atr then state[-2] == :a ? (state.push(:hrf); r) : ""
else r
end
when /\=/
case state.last
when :hrf then state.push(:eql); r
when :atr then ""
else r
end
when /\n/
case state.last
when :nml, :a then "<br/>"
when :atr then state[-2] == :a ? " " : ""
end
when /&/
"&"
else
case state.last
when :atr then ""
else r
end
end
}.join
end
if __FILE__ == $0
a = DATA.read.split(/DELIM\n/)
while true
pr = a.slice!(0,2)
puts filter(pr[0]) == pr[1]
break if a.empty?
end
end
__END__
<a foo="" href='www.g>oogle.com'>link</a>DELIM
<a href='www.g%3Eoogle.com'>link</a>DELIM
<script foo="<script>alert('bar')</script>">alert('foo')</script>DELIM
<script foo="<script>alert('bar')</script>">alert('foo')</script>DELIM
<script foo="<a href='link'>link</a>">alert('foo')</script>DELIM
<script foo="<a href='link'>link</a>">alert('foo')</script>DELIM
|
にしお
#3413()
Rating-2/2=-1.00
また、ユーザの入力注の<br>は<br/>に変換してください。
このお題はperezvonさんの提案を元にした三部作の二問目です。ご協力ありがとうございました。
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