SHLWAPI Functions

The large table on this page is this study’s master list of functions that appear in the export directory of any known version of SHLWAPI. It gives for each function just brief summaries of the applicable SHLWAPI versions and of the function’s status with respect to Microsoft’s documentation.

This master list is the key to other lists. More detail on each function’s availability and documentation status is to be found by looking for the function in the history lists, according to the function’s first version and to whether it is exported by name or with an ordinal. A separate list covers usage by other executable modules distributed with Windows (though presently specific to Windows XP Service Pack 1). Some functions link directly to an attempt at alternative documentation.

Additional explanatory notes follow the table.

Notes

Familiarity is assumed with the Reading Guide for the Windows Shell Study.

Names

Function names are reproduced from the export directory of the SHLWAPI.DLL executable, wherever possible. For functions that are not exported by name (i.e., are exported only by ordinal) from any known SHLWAPI version, names are inferred from symbol files that Microsoft supplies for customer support. If a function is known as an ordinal-only export from at least one SHLWAPI version, then even if later versions also export the function by name, the ordinal persists and is given in brackets immediately after the function’s name. An ordinal is also given in brackets even if a function is exported by name in all known SHLWAPI versions, provided that the ordinal breaks the auto-numbering of named exports and seems to persist across versions.

Versions

The SHLWAPI versions shown for each function are inferred from a study of known releases, making reasonable assumptions about likely continuity, especially to suppose that a function will exist in future versions or that a function exists in all (released) builds of a version if no counter-example is yet known.

Documentation Status

Except where otherwise stated, the reference version for Microsoft’s documentation is the January 2007 edition of the Windows Vista Software Development Kit (as distributed by Microsoft on MSDN Disc 3667), especially but not only under the heading Shell Lightweight Utility Functions. Some SHLWAPI functions are documented under headings that have no immediate relationship to SHLWAPI. For instance, some are documented as Shell Functions under Windows Shell. I expect this scattering occurs because the documentation models someone’s notions of functionality, regardless of where the functionality actually got implemented. However it comes about, it makes as good a reminder as any for caution: that a function is not marked above as “documented” (or is marked on other pages as “undocumented”) does not mean for certain that Microsoft does not document it, just that I haven’t yet found where.

Functions that were documented among the Settlement Program Interfaces in late 2002 are labelled specifically as “documented for settlement”. Some functions that predate the January 2004 edition of the MSDN Library on CD (which was the previous reference version for this study) and were not documented therein have got documented since. These are labelled as “documented” but with a year or range of years, according to whatever precision I happen to know. In particular, functions for which I noticed documentation when consulting the on-line MSDN Library in late 2004 are labelled “documented in 2004”.

One function is not documented specifically as an export from SHLWAPI but fits a general case described in the reading guide. It is indicated by enclosing the documentation status in brackets.