Don't write xml parsers in shell. Even the simplest one. Use right tools for job.
---

Code:

while read LINE; do
...
done <INPUTFILE

won't work well either, because of
1. It squashes the first blank spaces. 2. It wouldn't work if the last line doesn't end on the newline char. 3 It has quirks if a line has backslashes:

Code:

cat TESTFILE
<foo a="1">
    <bar b="2" c="Some string\n">
    </bar>
</foo>%
% while read -r LINE; do
  echo "$LINE"
done <TESTFILE
<foo a="1">
<bar b="2" c="Some string
">
</bar>

Yes, there are ways to do with it and shell is a programming language and it allows to do everything with it. But sed is Turing complete too.