"%s" random concatenation in R

Question

I am looking for a way to concatenate a string or a number (3 digits at least) into a save file. For instance, in python I can use '%s' % [format(str), format(number)]) and add it to csv file with a random generator.

How do I generate a random number into a format in R? That is my save file and I want to add a random string or a number in the end of the file name:

file = paste(path, 'group1N[ADD FORMAT HERE].csv',sep = '')

file = paste(path, 'group1N.csv',sep = '') to become -- >

file = paste(path, 'group1N212.csv',sep = '') or file = paste(path, 'group1Nkut.csv',sep = '') 

after using a random generator of strings or numbers and appending it to the save .csv file, each time it is saved, as a random generated end of file

Answer 1

You could use the built-in tempfile() function:

 tempfile(pattern="group1N", tmpdir=".", fileext=".csv")
[1] "./group1N189d494eaaf2ea.csv"

(if you don't specify tmpdir the results go to a session-specific temporary directory).

This won't write over existing files; given that there are 14 hex digits in the random component, I think the "very likely to be unique" in the description is an understatement ... (i.e. at a rough guess the probability of collision might be something like 16^(-14) ...)

The names are very likely to be unique among calls to ‘tempfile’ in an R session and across simultaneous R sessions (unless ‘tmpdir’ is specified). The filenames are guaranteed not to be currently in use.