Read a file incrementally in R, when that file is being occasionally written to by another process

read_incrementally.R

fname = 'temp.txt'
#wait for it to exist
while(!file.exists(fname)){}
old = 0
new = old
while(T){
	while(new==old){
		new = file.size(fname)
	}
	f = file(
		description = fname
		,  open = 'rb'
	)
	seek(con = f, origin = 'start', where = old)
	temp = readLines(f)
	#show a bit of info
	print(c(length(temp),substr(temp[1],1,1),old,new))
	close(f)
	old = new
}