hello experts,

I want to get the value between 2 patterns.
ex. get hello in <line>hello</line>
Any suggestions?
any sed, grek, awk commands?

If the patterns are always on a single line, awk or sed should work fine. If this is a more complex file, look in the Perl FAQ (section 6 IIRC) for some canned solutions.

This is a very frequently recurring question in these forums; try searching some recent threads.

Another approach:

Regards

Except that will also get anything outside of the separators. And you don't need the parens if you don't use them for backreferences. Anyway, it would be useful to have more precise requirements. Is there text outside of the separators? Do they span multiple lines? Are there other <tags> which are not to be used as separators? Can there be multiple occurrences of the tag pairs on one line?

Edit: I was referring to shamrock's solution. Wow, this is a popular thread.

yes, there are more text outside the separators. I'm trying to change the command people provide me to make it more suitable for my case.
and maybe my sed is too old, I get unrecognized command with
sed -n 's%.*<line>%%; T; s%</line>.*%%p'

Thanks you

file:
<b>asdfasdfasdf</b>
<line>hello</line>
<a>asdfasdfasdf</c>

output:
hello