The following are special features of description blocks:

• Description files can contain macro definitions and use macros in description blocks. Macros allow easy substitution of one text string for another.

• Description files can contain inference rules. Inference rules allow NMAKE to infer which commands to execute based on the file-name extensions used for targets and dependents.

• You can specify directories for NMAKE to search for dependent files by using the following syntax:

  targets : {directory1;directory2...}dependent ...

  NMAKE searches the current directory first, then <directory1>, <directory2>, and so on.

• A command can be placed on the same line as the target and dependent files by using a semicolon (;) as depicted below:

  targets... : dependents... ; command
  

• A long command can span several lines if each line ends with a backslash ( \ ):

  command \
    continuation of command
  

• The execution of a command can be modified if you precede the command with special characters.

• If you do not specify a command in a description block, NMAKE looks for an inference rule to build the target.

• DOS and OS/2 wildcard characters (* and ?) can be used in description blocks. For example, the following description block compiles all source files with the .C extension:

  ASTRO.EXE : *.C
    ICC $**
  

• NMAKE will expand the *.C specification into the complete list of C files in the current directory. $** is a complete list of dependents specified for the current target.

• NMAKE uses several punctuation characters in its syntax. To use one of these characters as a literal character, place an escape character ( ^ ) in front of it. For a list of punctuation characters, see Escape Characters.

• Normally a target file can appear in only one description block. A special syntax allows you to use a target in several description blocks.

• A special syntax allows you to determine the drive, path, base name, and extension of the first dependent file in a description block.