PathCombine

PathCombine is a programming utility used to join multiple parts of a filesystem path into a single, valid path. It is implemented in various forms across platforms and languages to simplify path construction and improve portability. Notable implementations include the Windows API function PathCombine from Shlwapi and high-level libraries such as .NET’s System.IO.Path.Combine.

The primary purpose of PathCombine is to concatenate path segments while applying the correct directory separators for the target platform, avoiding duplicate separators and producing a well-formed result. Some implementations also handle cases where the second path component is absolute, effectively replacing the base path with the absolute segment. Others simply append the segments. In many environments, PathCombine does not normalize relative references like … or ., and normalization must be performed separately if needed.

Common usage involves building file or resource paths relative to a base directory, ensuring that the resulting path is valid for subsequent file operations. Different languages provide analogous functions with similar goals, such as path joining in Node.js and Python, which share the idea of safely combining path components.

Limitations and distinctions should be noted: PathCombine typically focuses on proper separators and basic concatenation, not full path normalization. For canonical paths, additional normalization steps or calls to a separate function may be required.

See also: Path.Combine, Path.Join, path joining in various languages, path normalization.