Skip to main content

ExtractFilePath

Function ExtractFilePath( const FileName : string) : string

Example​

procedure ScriptEvent(var Value: variant);
begin
  Value := ExtractFilePath('C:\Fictional\Inbound\order.csv');
  // C:\Fictional\Inbound\
end;

Usage​

ExtractFilePath returns the drive and directory portion of a file-name string including its final delimiter.

Parameters

NameTypeDescription
FileNamestring, constFile-name or path text to parse.

Returns

The prefix through the final backslash or drive colon on the current Windows build, or an empty string when neither occurs.

Behaviour

  • 'C:\Folder\report.csv' returns 'C:\Folder\'.
  • 'C:\report.csv' returns 'C:\'.
  • 'C:report.csv' returns 'C:'; this is drive-relative syntax, not a rooted directory.
  • 'report.csv' returns ''.
  • A path already ending in a backslash is returned in full.

Errors

There is no normal path-content exception. Argument conversion and allocation failures can propagate.

Usage notes

This return form is convenient for lexical concatenation because it retains the final delimiter. Prefer IncludeTrailingPathDelimiter when starting from directory text whose delimiter state is unknown.

Additional Technical Info​

ExtractFilePath returns the drive and directory prefix through the final recognised path or drive delimiter. Unlike ExtractFileDir, an ordinary trailing delimiter is retained.

The example is source-reviewed and was not executed by the documentation workflow. Parsing is lexical and does not require a real path.

Implementation

Velox's wrapper calls installed System.SysUtils.ExtractFilePath. The terminal routine finds the last platform path delimiter or drive delimiter and copies the string up to and including it.

Edge cases and quirks

  • On the Windows build, a forward slash is not recognised as PathDelim. Mixed/URL-style paths can return an unexpected prefix or an empty string.
  • The function does not guarantee that a non-empty result is absolute. Drive-relative and relative-directory text remains relative.
  • It performs no separator collapse, ./.. resolution, environment expansion or existence check.
  • UNC and device prefixes are preserved only lexically.
  • Concatenating an unvalidated suffix can still escape the intended location through .. or rooted input. Enforce an approved path policy separately.

Side effects

None.

Performance and concurrency

The implementation scans backward and copies a prefix, so work is linear in path length. It has no mutable shared state.

Related entries

External references

Created 2026-07-15