If you have the Microsoft Windows Software Development Kit (SDK), you can access help files created with the SDK help compiler by calling the $WINHELP library routine. You can also access compiled HTML files that have the .chm extension. This is a support routine for Windows and Windows NT, and is not portable to other systems.

$WINHELP provides a direct interface to the Microsoft "WinHelp" library routine for files created with the SDK help compiler. This routine allows you to perform various functions using Microsoft Help. Normally, you would use this to allow the user to browse help information associated with your application.

For compiled HTML files whose names end with the .chm extension, $WINHELP invokes the Microsoft HTML Help Viewer application hh.exe.

Note: $WINHELP is not supported in Microsoft Windows Vista. Vista does not support WinHelp files (.hlp) meaning any programs that use the $WINHELP routine will no longer function. Microsoft is encouraging developers to transition their help file formats to CHM, HTML, or XML.




HELP-FILE PIC X(n) This is the file name of the help file.
OP-CODE Numeric parameter This value indicates the desired operation.
PARAM-VAL Type depends on op-code This is an operation-dependent parameter. It may be omitted for several operations.

The behavior of this routine is affected by the FILENAME_SPACES configuration variable. The value of FILENAME_SPACES determines whether spaces are allowed in a file name. See the entry for FILENAME_SPACES in Appendix H for more information.