UniBasic Commands Reference - Rocket Software

If STACKCOMMON is off when one program executes another, the
unnamed common is passed to the executed program and back to the
executing program.
If STACKCOMMON is on when one program executes another program,
unnamed common is not passed to the program you execute. Instead,
unnamed common is saved, and the unnamed common of the called
program is initialized to 0. When control is passed back to the calling
program, unnamed common is restored to its value before the program call.
Unnamed common is never passed to a phantom program.
Note: STACKCOMMON is always on in BASICTYPEs P and M. The default setting
for STACKCOMMON is off in BASICTYPEs R and U.
Parameters
The following table describes each parameter of the syntax.
Parameter Description
str.expr Specifies a UniData command with appropriate parameters. If you pass
a file name to MDPERFORM, you must use the actual file name, not a
file variable (which is assigned in the OPEN statement).
CAPTURING,
dyn.array.var
RETURNING,
dyn.array.var
The CAPTURING clause stores the output in a dynamic array instead
of on the display terminal. Each line of the text becomes an attribute in
the array. Output sent to the printer is not affected by this clause.
The RETURNING clause captures error messages resulting from the
command executed with MDPERFORM. This variable contains a
string of error message numbers separated by spaces. If the executed
command creates a spooler hold file, UniData also returns the hold file
number in the same variable.
MDPERFORM Parameters
MDPERFORM 1-467