Extracting File Basename without Extension
On Fri, 9 Jan 2009, Berwin A Turlach wrote:
G'day Wacek, On Fri, 09 Jan 2009 12:52:46 +0100 Wacek Kusnierczyk <Waclaw.Marcin.Kusnierczyk at idi.ntnu.no> wrote:
Berwin A Turlach wrote:
G'day all, On Fri, 9 Jan 2009 08:12:18 -0200 "Henrique Dallazuanna" <wwwhsd at gmail.com> wrote:
Try this also: substr(basename(myfile), 1, nchar(basename(myfile)) - 4)
Or, in case that the extension has more than three letters or "myfile" is a vector of names: R> myfile <- "path1/path2/myoutput.txt" R> sapply(strsplit(basename(myfile),"\\."), function(x) R> paste(x[1:(length(x)-1)], collapse=".")) [1] "myoutput" R> myfile2 <- c(myfile, "path2/path3/myoutput.temp") R> sapply(strsplit(basename(myfile2),"\\."), function(x) R> paste(x[1:(length(x)-1)], collapse=".")) [1] "myoutput" "myoutput" R> myfile3 <- c(myfile2, "path4/path5/my.out.put.xls") R> sapply(strsplit(basename(myfile3),"\\."), function(x) R> paste(x[1:(length(x)-1)], collapse=".")) [1] "myoutput" "myoutput" "my.out.put"
using fixed = TRUE and not escaping '.' is slightly more efficient.
or have sub do the job for you:
filenames.ext = c("foo.bar", basename("foo/bar/hello.dolly"))
(filenames.noext = sub("[.][^.]*$", "", filenames.ext, perl=TRUE))
Apparently also a possibility, I guess it can be made to work with the original example and my extensions. Though, it seems to require the knowledge of perl, or at least perl's regular expression.
Actually, that's a valid regex in any of the variants offered. A more conventional writing of it is the second of
f <- 'foo.bar.R'
sub("[.][^.]*$", "", f)
[1] "foo.bar"
sub("\\.[^.]*$", "", f)
[1] "foo.bar"
It is the last that is used at various points in R's own code
(although sometimes with restrictions on what an 'extension' is, e.g.
sub("\\.[[:alnum:]]*$", "", f)
appears in the current SHLIB code.)
Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595