grep substring between quotes

Question

Let's say I have a string like this:

title="2010-09-11 11:22:45Z"

How can I grep the date itself and disregard the quotes/title/Z?

The file can contain more strings like:

randomstring
title="2010-09-11 11:22:45Z"
title="disregard me"

So I only want to grep timestamps with a single grep command.

Solution 1

With GNU grep, you can do:

$ echo 'title="2010-09-11 11:22:45Z"' | grep -oP 'title="\K[^"]+'
2010-09-11 11:22:45Z

Solution 2

If input would be in this format only then below command will easily solve your problem

echo "title=\"2010-09-11 11:22:45Z\"| cut -d '"' -f2 

Solution 3

grep -oP '[0-9-]{10} [0-9:]{8}' filename

Solution 4

This should work only on the GNU version of grep:

<file.html grep -oP "(?<=title\=\")\d+-\d+-\d+"

Example on regex101 here.

View more solutions

Comments

[groxxda]

sed 's/.*="\(.*\)"/\1/'

[polym]

@Groxxda thanks, but is it possible in grep, too?

[groxxda]

grep -o '".*"' | tr -d '"'

[polym]

I don't get why this question is downvoted so often. It's a simple question: grep timestamps using one command only.

[groxxda]

Are hours and day always two digits?

[phemmer]

@polym This is probably being downvoted for a few reasons. 1) your original question mentioned html, and you should not attempt to regex through html. 2) you altered your question after it had been answered, to which the most upvoted answer is no longer a solution to the question. 3) this also is starting to sound like an X/Y problem, but this is just my own feeling, and probably not downvote worthy.

[polym]

@Groxxda hours and days are always like it's represented above.

[Buttle Butkus]

no explanation, what is K?

[cuonglm]

@ButtleButkus: \K is PCRE syntax, which don't include anything in left side of \K in matching result, or in Perl way, don't include in $&.

[DimiDak]

thanx a lot man. If you could include also that each flag it's doing.. Would be perfect.