← SASnRGet the list the files in a Directory/Folder to a dataset

Introduction

A common utility task: read the list of files in a folder into a dataset so we can loop over them, filter by extension, or join against an expected-file manifest.
We want columns like full_filename (path + name), filename (name only), basename (name without extension), and extension.
SAS uses the filesystem functions dopen(), dnum(), dread(), and dclose() to walk a directory, plus scan() and substr() to split the name and extension.
Tidyverse uses list.files() plus the tools package helpers file_path_sans_ext() and file_ext().
Base R uses the same list.files() and tools helpers — no extra package required.
This lesson builds the file-list data frame for a local folder and derives the basename and extension for each entry.

Get the list the files in a Directory/Folder to a dataset

SAS (Base SAS)+

R (tidyverse)+

library(tidyverse)

folder_path <- "C:/Users/curio/Desktop/Rough"

file_list <- tibble(
  full_filename = list.files(path = folder_path,full.names = TRUE),
  filename = list.files(path = folder_path),
  folder = folder_path,
  basename = tools::file_path_sans_ext(filename),
  extension = tools::file_ext(filename)
)

In tidyverse, list.files() returns a character vector of file names — that alone replaces most of the SAS DATA-step plumbing.
list.files(path = folder_path, full.names = TRUE) returns the full path to each file; without full.names, we get just the file names.
We call it twice — once with full.names = TRUE for the full_filename column and once without for the filename column.
tools::file_path_sans_ext(filename) strips the extension off the name, giving us basename.
tools::file_ext(filename) returns just the extension string — "txt", "csv", etc.
All five pieces drop into a tibble() in one call, giving us one row per file with name, folder, basename, and extension.
We run and inspect FILE_LIST; each row should match a real file in the folder with the parts correctly split.

Happy learning!

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Introduction

Get the list the files in a Directory/Folder to a dataset