As an alternative to placing all the options on the command line, the MIDL compiler accepts response files that contain switches and arguments. A response file is a text file containing one or more MIDL compiler command-line options. Unlike a command line, a response file allows multiple lines of options and filenames. This is important on systems such as MS-DOS that have a hard-coded limit on the length of a command line. You can specify a MIDL response file as:
midl @filename
Options in a response file are interpreted as if they were present at that place in the MIDL command line.
Each argument in a response file must begin and end on the same line. You cannot use the backslash character (\) to concatenate lines.
MIDL supports command-line arguments that include one or more response files, combined with other command-line switches:
midl -pack 4 @midl1.rsp -env win32 @midl2.rsp itf.idl
The MIDL compiler does not support nested response files.