On Oct 31, 2012, at 9:56 AM, chuck.01 wrote:
> Sorry, I know I should read a little 1st about this, but I am actually just
> helping somebody really quick and need help too.
>
> I want to grep all of the names of the .txt files mentioned on this html web
> page:
>
> http://www.epa.gov/emap/remap/html/three/data/index.html
This shows code that will identify lines in that source page containing URLs
that end in '.txt"'
> lines <-
> readLines(con=url("http://www.epa.gov/emap/remap/html/three/data/index.html";)
> )
Warning message:
In readLines(con =
url("http://www.epa.gov/emap/remap/html/three/data/index.html";)) :
incomplete final line found on
'http://www.epa.gov/emap/remap/html/three/data/index.html'
# You can generally ignore that warning.
> length(grep('\\"http://([./A-Za-z]){1+}\\.txt"', lines) )
[1] 11
Should be fairly straightforward to remove the preceding and trailing material.
> sub('(^.*\\")(http://([./A-Za-z]){1+}\\.txt)(".*$)', "\\2", lines[
> grep('\\"http://([./A-Za-z]){1+}\\.txt"', lines) ] )
[1]
"http://www.epa.gov/emap/html/data/surfwatr/data/mastreams/9396/benthic/benmet.txt";
[2]
"http://www.epa.gov/emap/html/data/surfwatr/data/mastreams/9396/benthic/bencnt.txt";
[3]
"http://www.epa.gov/emap/html/data/surfwatr/data/mastreams/9396/location/watchr.txt";
[4]
"http://www.epa.gov/emap/html/data/surfwatr/data/mastreams/9396/location/habbest.txt";
[5]
"http://www.epa.gov/emap/html/data/surfwatr/data/mastreams/9396/design/sdesign.txt";
[6]
"http://www.epa.gov/emap/html/data/surfwatr/data/mastreams/9396/wchem/chmval.txt";
[7]
"http://www.epa.gov/emap/html/data/surfwatr/data/mastreams/9396/fish/fshmet.txt";
[8]
"http://www.epa.gov/emap/html/data/surfwatr/data/mastreams/9396/fish/fshcnt.txt";
[9]
"http://www.epa.gov/emap/html/data/surfwatr/data/mastreams/9396/fish/fshnam.txt";
[10]
"http://www.epa.gov/emap/html/data/surfwatr/data/mastreams/9396/tissue/ftmet.txt";
[11]
"http://www.epa.gov/emap/html/data/surfwatr/data/mastreams/9396/tissue/ftorg.txt";
>
> Thanks ahead of time.
>
>
>
> --
> View this message in context:
> http://r.789695.n4.nabble.com/grep-txt-file-names-from-html-tp4648037.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> R-help@r-project.org mailing list
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
David Winsemius, MD
Alameda, CA, USA
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
