isCOBOL Evolve : Appendices : Library Routines : M$COPY
M$COPY
The M$COPY library routine copies memory from the source memory area to the destination memory area.
The involved memory regions are usually allocated with the M$ALLOC library routine. However, programs compiled with -cp option may operate also on a memory regions allocated by external C functions or by a Format 7 SET statement.
Syntax:
 CALL "M$COPY" USING destination 
                     source
                     length
Parameters:
destination
USAGE HANDLE
Specifies the handle to the destination memory region.
 
Note - for compatibility reasons this item may also be defined as USAGE POINTER. In this case the program must be compiled either with -ca or -cp options. With -ca POINTER is translated to HANDLE. With -cp POINTER is a real pointer that can be shared with external C routines.
source
USAGE HANDLE
Specifies the handle to the source memory region.
 
Note - for compatibility reasons this item may also be defined as USAGE POINTER. In this case the program must be compiled either with -ca or -cp options. With -ca POINTER is translated to HANDLE. With -cp POINTER is a real pointer that can be shared with external C routines.
length
any numeric data item or numeric literal
Specifies the number of bytes to be copied.
Examples:
Example - Allocate 8 bytes of memory on each handle, fill 1 with X characters and then copy first memory contents to second memory area
*> define mem1 and mem2 usage handle
 
call "m$alloc" using 8, mem1
call "m$alloc" using 8, mem2
call "m$fill" using mem1, "X", 8
call "m$copy" using mem1, mem2, 8