This is a Silverfrost library function.
The value of IFAIL refers to the success or failure of invoking the MS-DOS
command processor COMMAND.COM. Unfortunately, MS-DOS does not provide a
mechanism whereby the success or failure of the invocation of the particular
command can be reported back to the caller. So, for example, if you get a
system error such as "Not found" for the command, IFAIL will be returned as