NAME
 _DOSBase auto-open

 SYNOPSIS

 FUNCTION
 If the _DOSBase base variable is referenced (i.e. extern) but not
 declared then _DOSBase will be automatically declared in the doslib
 module of auto.lib.  Additionally, auto.lib adds routines to the
 autoinit and autoexit sequences called by c.a that automatically
 opens "dos.library" before _main and closes it after _exit.

 If the auto-open fails the program will be aborted before _main is
 ever called.

 The autoexit routine that closes the library first checks to see if
 the base variable is NULL and skips trying to close the library if
 so.

 NOTE
 _DOSBase is normally openned this way for most programs since parts
 of c.a are normally reference that make dos calls.  In fact, all
 programs that use the main() entry point since c.lib's _main()
 entry point references DOS.

 EXAMPLE

 SEE ALSO