How to use R's sprintf to create fixed width strings with fill whitespace at the END?

Question

I have vector of strings and want to create a fixed with string out of that. Shorter strings should be filled up with white spaces. E.g.:

c(\"fjdlksa01dada\"         


        

Answer 1

That is almost more of a standard "C" rather than R question as it pertains to printf format strings. You can even test this on a command-prompt:

edd@max:~$ printf "[% 8s]\n" foo
[     foo]
edd@max:~$ printf "[%-8s]\n" foo
[foo     ]
edd@max:~$ 

and in R it works the same for padding left:

R> vec <- c("fjdlksa01dada","rau","sjklf")
R> sprintf("% 8s", vec)
[1] "fjdlksa01dada" "     rau"      "   sjklf"     
R> 

and right

R> sprintf("%-8s", vec)
[1] "fjdlksa01dada" "rau     "      "sjklf   "     
R> 

Edit: Updated once I understood better what @ran2 actually asked for.

Answer 2

The stringr package provides str_pad:

library(stringr)
x <- c("fjdlksa01dada","rau","sjklf")
str_pad(x, width=8, side="right")

which yields:

[1] "fjdlksa01dada" "rau     "      "sjklf   "

Answer 3

Add a minus in front of the 8 to get a left-aligned padded string