get_path_info: Extract Path Segments or Filenames from File Paths

In mintyr: Grouped and Nested Data Pipelines Built on 'data.table'

Extract Path Segments or Filenames from File Paths

Description

get_path_info is a merged, upgraded replacement for get_path_segment and get_filename. It operates in two modes:

• Mode A (when n is specified): Extract a specific path segment by position, supporting forward indexing, reverse indexing, and range extraction.

• Mode B (when n = NULL): Extract the filename, with optional removal of the file extension and/or the directory prefix.

Usage

get_path_info(path, n = NULL, rm_extension = TRUE, rm_path = TRUE)

Arguments

path	A character vector of file system paths. Supports mixed separators (/ and ⁠\\⁠) and Windows drive letters (e.g. ⁠C:⁠).
n	A numeric segment index. Defaults to NULL (enters filename mode). Positive integer: forward index from the path start; 1 = first segment. Negative integer: reverse index from the path end; -1 = last segment (i.e. the filename segment). Length-2 vector: extract a contiguous range, e.g. c(2, 4) or c(-3, -1). 0 is not allowed.
rm_extension	A logical(1) flag controlling extension removal. Defaults to TRUE. In Mode B (n = NULL): always applied. In Mode A: only applied when n == -1 (explicitly targeting the filename segment). Has no effect for intermediate directory segments (e.g. n = 2).
rm_path	A logical(1) flag controlling whether the directory prefix is stripped, keeping only the filename. Defaults to TRUE. Only applies in Mode B (n = NULL); ignored when n is specified. With rm_path = FALSE the normalised path keeps its root (/, ⁠C:/⁠ or ⁠//⁠ for UNC paths), so absolute paths stay absolute.

Details

Path normalisation (internal, fully vectorised):

1. All backslashes and consecutive slashes are collapsed to a single /.

2. Windows drive letter prefixes (⁠C:⁠, ⁠D:⁠, etc.) are stripped for segment indexing (and restored in full-path mode).

3. Leading and trailing / characters are removed.

4. Paths that are empty after the above steps (e.g. original inputs "C:/", "/", "") are coerced to NA_character_.

Extension-stripping behaviour (internal .strip_ext helper):

Input	Output	Notes
"report.txt"	"report"	Standard file — last extension removed
"data.tar.gz"	"data.tar"	Compound extension — only last level removed
".bashrc"	".bashrc"	Pure dot-file (no second dot) — unchanged
".report.xlsx"	".report"	Dot-file with extension — extension removed
"no_ext"	"no_ext"	No extension — returned as-is
"file."	"file."	Trailing isolated dot — returned as-is

NA safety: strsplit(NA_character_, ...) returns list(NA) with length 1, not character(0). Consequently, every vapply callback guards against NA paths with an explicit anyNA(x) check rather than length(x) == 0.

Value

A character vector of the same length as path:

• Returns the extracted segment string when the segment exists.

• Returns NA_character_ when the segment index exceeds the path depth, the input element is NA, or the path reduces to empty after normalisation (e.g. "C:/", "/").

See Also

base::basename(), tools::file_path_sans_ext()

Examples

paths <- c("C:/Users/foo/Documents/report.xlsx",
           "/home/user/.bashrc",
           "relative/path/to/data.csv",
           ".hidden.tar.gz",
           NA_character_)

# Mode B: filename only, extension stripped (default)
get_path_info(paths)

# Mode B: filename only, extension preserved
get_path_info(paths, rm_extension = FALSE)

# Mode B: full normalised path, extension stripped
get_path_info(paths, rm_path = FALSE)

# Mode A: extract the 2nd path segment
get_path_info(paths, n = 2)

# Mode A: extract the last segment with extension stripped (n = -1 linkage)
get_path_info(paths, n = -1, rm_extension = TRUE)

# Mode A: range extraction
get_path_info(paths, n = c(2, 3))

mintyr documentation built on Oct. 5, 2026, 5:08 p.m.