These ‘-m’ options are defined for the VMS implementations:
Return VMS condition codes from
main. The default is to return POSIX-style
condition (e.g. error) codes.
Flag the first routine whose name starts with prefix as the main routine for the debugger.
Default to 64-bit memory allocation routines.
Set the default size of pointers. Possible options for size are
‘32’ or ‘short’ for 32 bit pointers, ‘64’ or ‘long’
for 64 bit pointers, and ‘no’ for supporting only 32 bit pointers.
The later option disables