The following table lists additional miscellaneous global functions:

Miscellaneous Functions
Function	Description
DtSleep()	Provides a machine-independent way to halt program execution for some period of time. It's argument is the time, in seconds, for which to "sleep". The implementation of DtSleep() is machine-dependent, but it uses system calls such as UNIX's select, rather than a CPU-intensive busy loop. (For more information, please see vlProcessControl.h.)
DtSelect()	Provides a machine-independent interface to the UNIX select system call, which takes different arguments on different platforms. DtSelect()'s arguments are a number of file descriptors, three arrays of file descriptors to monitor for presence of data to read, availability for writing, and pending exceptional conditions, respectively, and a timeout in seconds. On Windows, DtSelect() interprets a file descriptor of 0 as stdin. (For more information, please see vlutil.h.)
DtAbort()	Called whenever VR-Link generates a fatal error, it makes the abort system call. If you need to modify VR-Link's abort behavior, you can write your own definition for DtAbort(). Because VR-Link's definition for DtAbort() resides in its own object file, your definition will merely supersede ours with no other effects. If your definition is linked into your application through a library that you create (rather than through an object file on your link line), make sure that your library appears before vlutil on your link line. (For more information, please see vlPrint.h.)