Export UTF-8 BOM to .csv in R

The accepted answer did not help me in a similar application (R 3.1 in Windows, while I was trying to open the file in Excel). Anyway, based on this part of file documentation:

If a BOM is required (it is not recommended) when writing it should be written explicitly, e.g. by writeChar("\ufeff", con, eos = NULL) or writeBin(as.raw(c(0xef, 0xbb, 0xbf)), binary_con)

I came up with the following workaround:

write.csv.utf8.BOM <- function(df, filename){    con <- file(filename, "w")    tryCatch({    for (i in 1:ncol(df))        df[,i] = iconv(df[,i], to = "UTF-8")     writeChar(iconv("\ufeff", to = "UTF-8"), con, eos = NULL)    write.csv(df, file = con)    },finally = {close(con)})}

Note that df is the data.frame and filename is the path to the csv file.

On help page to Encoding (help("Encoding")) you could read about special encoding - bytes.

Using this I was able to generate csv file by:

v <- "נווה שאנן"X <- data.frame(v1=rep(v,3), v2=LETTERS[1:3], v3=0, stringsAsFactors=FALSE)Encoding(X$v1) <- "bytes"write.csv(X, "test.csv", row.names=FALSE)

Take care about differences between factor and character. The following should work:

id_characters <- which(sapply(X,    function(x) is.character(x) && Encoding(x)=="UTF-8"))for (i in id_characters) Encoding(X[[i]]) <- "bytes"id_factors <- which(sapply(X,    function(x) is.factor(x) && Encoding(levels(x))=="UTF-8"))for (i in id_factors) Encoding(levels(X[[i]])) <- "bytes"write.csv(X, "test.csv", row.names=FALSE)