Try this: library(gsubfn)
strapply("blah blah start=20080101 end=20090224", "start=(\\d{8}) end=(\\d{8})", c, perl = TRUE)[[1]] or perhaps just: strapply("blah blah start=20080101 end=20090224", "\\d{8}", perl = TRUE)[[1]] On Tue, Feb 24, 2009 at 7:23 PM, <pie...@demartines.com> wrote: > Hello, > > Newbie question: how do you capture groups in a regexp in R? > > Let's say I have txt="blah blah start=20080101 end=20090224". > I'd like to get the two dates start and end. > > In Perl, one would say: > > my ($start,$end) = ($txt =~ /start=(\d{8}).*end=(\d{8})/); > > I've tried: > > txt <- "blah blah start=20080101 end=20090224" > m <- regexpr("start=(\\d{8}).*end=(\\d{8})", filename, perl=T); > dates = substring(filename, m, m+attr(m,"match.length")-1); > > but I get the whole matching substring... > > Any idea? > > ~Pierre > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.