get filename and path of `source`d file

Question

How can a sourced or Sweaved file find out its own path?

Background:

I work a lot with .R scripts or .Rnw files. My projects are o

Answer 1

Just FYI, knitr will setwd() to the dir of the input file when (and only when) evaluating the code chunks, i.e. if you call knit('path/to/input.Rnw'), the working dir will be temporarily switched to path/to/. If you want to know the input dir in code chunks, currently you can call an unexported function knitr:::input_dir() (I may export it in the future).