extract_short_path: Extract the Last Two Path Components from a File Path
Description
This helper function takes any full file path and extracts only the last
two components, such as `"R/add.R"`. It supports both forward slashes (`/`)
and backslashes (`\`) to accommodate Windows, macOS, and Linux paths.
Usage
extract_short_path(long_file_name)
Value
A character scalar containing the last two components of the path joined
with a forward slash—for example `"R/add.R"`—or a single component if only
one exists. The returned value is always of class character.
Arguments
long_file_name
Character string. A full file path using `/` or `\`
as separators.
Output Meaning
This function is intended for display and logging purposes, where only the
tail portion of a full file path is meaningful. It does not check for file
existence; it simply processes the string supplied by the user.
Details
Trailing separators are preserved where meaningful (e.g., `"R/"` when the
input ends with a slash). Empty path components are removed except when
required to detect a trailing separator.