Might something like this be helpful?

c:\@Work\Perl\monks>perl -wMstrict -le
"my $look_for = qr{ (?<! [[:alpha:]]) home (?! [[:alpha:]]) }xms;
 ;;
 my $row = 'social_going_home';
 my $match = my ($capture) = $row =~ m{ (?<= _) $look_for \z }xmsg;
 ;;
 if ($match) {
   print qq{match, captured '$capture'};
   }
"
match, captured 'home'
[download]

Update: BTW: The pattern  feed* in the match of  if(/feed*/) { ... } matches any of  fee feed feedd feeddd ... Is that what you wanted?

thank you , I will look at your code .Yes, I wanted feed and any words or digits after, because there is "feed001, feed002" etc

... I wanted feed and any words or digits after ...

/d*/ matches zero or more  'd' characters, but does not match "words" (unless they're composed only of  'd' characters) and certainly not decimal digits. Perhaps you want something like  /feed[[:alnum:]]*/

c:\@Work\Perl\monks>perl -wMstrict -le
"for my $str (qw(
   feed feeder feed001 xfeed001x  fee fee001 xfeex --fee-- fe xxx 001
   )) {
   print qq{'$str' -> },
     $str =~ m{ feed [[:alnum:]]* }xms ? '' : 'NO', ' match';
   }
"
'feed' ->  match
'feeder' ->  match
'feed001' ->  match
'xfeed001x' ->  match
'fee' -> NO match
'fee001' -> NO match
'xfeex' -> NO match
'--fee--' -> NO match
'fe' -> NO match
'xxx' -> NO match
'001' -> NO match
[download]

Change the match pattern above to just  feed* to see the difference.

---

Give a man a fish:  <%-{-{-{-<

in order to get what I want

It isn't overly clear what you want. If you have a string with words separated by underscores and just want to return the last such word then you could do this:

my $row = 'We_need_feed';
my ($last) = $row =~ /[^_]*$/g;
print $last;
[download]

or you could split and then pop but maybe extracting the last isn't what you want at all.

thank you , I learned from your example. I wanted to extract just the word "feed", I was using my $result=$row=~/feed*/m but $result would just contain 0 or 1 which I read is expected, but your way gets the phrase.Thank you , but what does /^_*$/ do? You are saying you are searching for underscore at the front, followed by anything at the end? and what does the brackets [] do? Thank you

The square brackets indicate a character class and the caret inside negates what follows such that [^_] means any character other than an underscore. The dollar anchors it to the end. All this is in perlre and related pages which are well worth a read.