Beefy Boxes and Bandwidth Generously Provided by pair Networks
"be consistent"
 
PerlMonks  

Re: Limiting number of regex matches

by Marshall (Abbot)
on Sep 25, 2012 at 20:42 UTC ( #995630=note: print w/replies, xml ) Need Help??


in reply to Limiting number of regex matches

The easiest way is not to limit the number of regex matches, but to trim the results with a list slice.
Let match global do its thing and then return the first 3 matches.
#!/usr/bin/perl -w use strict; my $str='dog dog horse dog cow dog pig dog'; my @dogs = ($str =~ m/dog/g)[0..2]; print "number of dogs = ".@dogs,"\n"; # the . concatenation puts @dogs in a scalar context # same as print scalar(@dogs) print "@dogs\n"; ################## # so what happens if there aren't 3 dogs? # one way is to use map to filter the undef's out # To return a "nothing at all" from map, use () # undef is a value and that won't work... # # This returns a maximum of 3 dogs if there are that # many or more dogs, otherwise it returns less. # my $second_pack = "dog horse cow"; @dogs = map{$_ or ()}($second_pack =~ /dog/g)[0..2]; print "\nsecond pack = ".@dogs, " dogs\n"; print "@dogs"; __END__ number of dogs = 3 dog dog dog second pack = 1 dogs dog

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://995630]
help
Chatterbox?
[Corion]: marto: Live video or are they recording and storing inspection videos? If it's for archival, who is rewatching that stuff? ;)
[Discipulus]: imperial infiltration
[marto]: Corion none of it is live, all recordings, in the first instance they need to transfer video from dead/dying media (DVDR, VHS, Laserdisc and so on)
[marto]: Discipulus, yeah pretty much robots going around parts of the plant humans can't

How do I use this? | Other CB clients
Other Users?
Others imbibing at the Monastery: (9)
As of 2017-07-28 09:41 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?
    I came, I saw, I ...
























    Results (425 votes). Check out past polls.