i need to get the text between two words or text segments in a string.
I've searched and tried EVERTYHING with sed, and can't get it to work :S
I have a string like "aaa bbb ccc ddd eee" and i want to extract the text between, let's say, bbb and ddd.
Assuming bbb doesn't occur after the text you are interested in, and the reverse constraint for ddd, you can do it like this:
sed 's/^.*bbb //; s/ddd.*$//' <<< "aaa bbb ccc ddd eee"
Output:
ccc
sed is probably not the best tool for this, maybe you could explain a bit more about what you are trying to do? For example you may want to use positive lookbehind and lookahead:
grep -oP '(?<=bbb ).*?(?=ddd)' <<< "aaa bbb ccc ddd eee"
Output:
ccc
According to comments the OP wants to extract the ip address from checkip.dyndns.org. A generic and more portable way to do that is with grep -o, e.g.:
curl -s http://checkip.dyndns.org/ | grep -oE '([0-9]+.){3}[0-9]+'
<<< "aaa bbb ccc ddd eee" | grep syntax did not work on my system (ubuntu, bash4).
<<<"..." grep (no pipe), but your edit is also fine.
.*? non-greedy.. but this is not explained very clearly by OP. Your answer is good!
You could use sed groupings. The three pairs of parentheses denote three groupings. \2 on the output side is the content of the second grouping
sed 's/\(^.*bbb\)\(.*\)\(ddd.*$\)/\2/'
Assuming you don't want the spaces around the output text between bbb and ddd
sed 's|^\(.*bbb *\)\(.*\)\( *ddd.*\)$|\2|g'
