sed html parsing

Question

I have to parse HTML to change text between two brackets that are not HTML code back to < or >.

Here an example of my HTML code that I have to replace:

<content:encoded><![CDATA[<div class="pre_headline">some text</div> <p>…. More text . </p><p></p><h2> More text </h2><p> More text < text between angle brackets > … more text
… </content:encoded>

desired output:

<content:encoded><![CDATA[<div class="pre_headline">some text</div> <p>…. More text . </p><p></p><h2> More text </h2><p> More text &lt; text between angle brackets &gt; … more text
… </content:encoded>

All the text is in one line. All the replacement I'm doing now is with sed or awk. But I couldn't figure out a way to replace the brackets in text without changing all the html tags.

I thought to define that all html brackets are not followed by a space. the inline text brackets are usually followed by a space. This could be a way to choose which brackets i have to replace. Maybe there is a better rule, since this method would not replace text in brackets without space :(

The following sed command would replace all brackets.

sed -e 's/>/\>/g' | 
sed -e 's/</\&lt;/g' |

Answer 1

It is possible with sed but rather difficult then any XML parsers.

sed '
:2
#puts open and close tag in one pattern
/\s*<\([^>]*>\).*<\/\1\s*$/!{
    N
    b2
}
#mark pairable tags by `#` symbol
:1
s/\(.*<\)\(\([^#> ]*\).*<\)\/\3/\1#\2#\/\3/
#other variant
#s/\(.*<\)\(\([^><]*\)[^>]*>.*<\/\3\)>/\1#\2#>/
t1
#change non-marked text
s/<\([^#]*\)>/\&lt;\1\&gt;/g
#remove marks
s/#//g
' file.html