Append lines to a file

I'm new using R. I'm trying to add (append) new lines to a file with my existing data in R. The problem is that my data has about 30000 rows and 13000 cols. I already try to add a line with the writeLines function but the resulting file contains only the line added.

Have you tried using the write function?

line="blah text blah blah etc etc"
write(line,file="myfile.txt",append=TRUE)

write.table, write.csv and others all have the append= argument, which appends append=TRUE and usually overwrites if append=FALSE. So which one you want to / have to use, depends on your data.

By the way, cat() can also be used to write text to a file and also has the append= argument.