See details on *argument* 'open' for file(), cf. help("file"). /Henrik
On Wed, Sep 14, 2011 at 12:38 PM, Noah Silverman <noahsilver...@ucla.edu> wrote: > Hi, > > I want to keep a running file of some statistics generated by a running > process. Occasionally the process will be restarted. > > On restart, I'd like to read the last line of the log file to set some > variables to their last state, and then continue to append values to that > same file. > > I can't seem to get the appending part to work. I can read values form the > file, but then upon the first write, the file is overwritten with the new > values, so I lose my entire history. > > Any ideas? > > Here is what I'm using: > > > ============================= > outfile <- file("logfile.csv", open="r") > x <- readLines(outfile) > lastLine <- x[length(x)] > a <- as.numeric( strsplit(lastLine, " +")[[1]][1] ) > b <- as.numeric( strsplit(lastLine, " +")[[1]][2] ) > c <- as.numeric( strsplit(lastLine, " +")[[1]][3] ) > close(outfile) > > outfile <- file("logfile.csv", open="w") > > > while(1){ > # do a bunch of stuff > cat(a, b, c, sep=",", "\n", file=outfile, append=TRUE) > > } > > ========================= > > > -- > Noah Silverman > UCLA Department of Statistics > 8117 Math Sciences Building #8208 > Los Angeles, CA 90095 > > ______________________________________________ > 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.