To cite filesstrings in publications use:

Rory Nolan and Sergi Padilla-Parra (2017). filesstrings: An R package for file and string manipulation. The Journal of Open Source Software, 2(14). <doi:10.21105/joss.00260>.

Corresponding BibTeX entry:

  @Article{,
    title = {{filesstrings}: An R package for file and string
      manipulation},
    author = {Rory Nolan and Sergi Padilla-Parra},
    journal = {The Journal of Open Source Software},
    year = {2017},
    volume = {2},
    number = {14},
    url = {https://doi.org/10.21105/joss.00260},
    doi = {10.21105/joss.00260},
  }