write.table
can get you part of the way, but you will still need to do some fiddling around to get things to work just as you want.
Here's an example:
x <- capture.output(
write.table(head(cars), sep = "|", row.names = FALSE, eol = "|\n"))
x2 <- paste0("|", x)
x2[1] <- gsub("|", "||", x2[1], fixed=TRUE)
cat(x2, sep = "\n")
# ||"speed"||"dist"||
# |4|2|
# |4|10|
# |7|4|
# |7|22|
# |8|16|
# |9|10|
As a function, I guess in its most basic form it could look something like:
write.myOut <- function(inDF, outputFile) {
x <- capture.output(
write.table(inDF, sep = "|", row.names = FALSE, eol = "|\n"))
x <- paste0("|", x)
x[1] <- gsub("|", "||", x[1], fixed=TRUE)
cat(x, sep = "\n", file=outputFile)
}