Question

A function I wrote generates an output file. Additional functions can take the content of that file (the name has a pattern that can be easily matched), and do more. Currently one could do the following:

function1(...)
# This will generate a file, say output_typea.md
# Then one could process this content further using
function2(input_file = 'output_typea.md')

However, since these two functions are meant to be run in sequence, I’d like to just let users call function2() and missing input would just read the most recent file matching the dir(pattern = "*_type.md"). Unfortunately it doesn’t seem possible to sort dir() listings by date modified. All I need is the most recent file matching file name pattern. Any ideas?

Answer 1

Look up the ctime (or other) and return the appropriate file:

x <- dir()
y <- file.info(x)
row.names(y[y$ctime==max(y$ctime),])