• Directives can be nested to any depth, limited only by available memory.

• Included files can include other files as well, loops are not detected.

• Parentheses must be used to group expressions if a directive contains multiple expressions.

• Values are assumed to be decimal values unless specified with a leading 0 (octal) or a leading 0x (hexadecimal).

• Strings are enclosed by double quotes ("). You can use the equality (==) and inequality (!=) operators to compare two strings.

• A program can be invoked in an expression by enclosing the program name in square brackets ([ ]). The exit code returned by the program is used in the expression. Such programs will always be invoked if the directive is evaluated, even if -N has been specified.

Example

Using the following description file excerpt:

     !INCLUDE <INFRULES.TXT>     !CMDSWITCHES +D
     WINNER.EXE: WINNER.OBJ
     !IFDEF DEBUG
     !   IF "$(DEBUG)" == "y"
            ilink /DE WINNER.OBJ;
     !   ELSE
            ilink WINNER.OBJ
     !   ENDIF
     !ELSE
     !    ERROR Macro named DEBUG is not defined.
     !ENDIF

The !INCLUDE directive causes the file INFRULES.TXT to be read and evaluated as if it were part of the description file.

The !CMDSWITCHES directive turns on the /D option, which displays the dates of the files as they are checked.

The !IFDEF directive checks to see whether the macro DEBUG is defined. If it is defined, the !IF directive checks to see whether it is set to 'y'. If it is, the linker is invoked with the /DE option; otherwise, it is invoked without the /DE. If the DEBUG macro is not defined, the !ERROR directive prints out the message and NMAKE32 stops executing.