Rational Developer for System z
PL/I for Windows, Version 8.0, Programming Guide

Inline files

You may need to issue a command in the description file with a list of arguments exceeding the command-line limit of the operating system. Just as NMAKE supports the use of command files, it can also generate inline files which are read as response files by other programs.

To generate an inline file, use the following syntax for your description block:

target : dependents
  command @<<[filename]
inline file text
<< [KEEP | NOKEEP]

All of the text between the two sets of double less than signs (<<) is placed into an inline file and given the name filename. You can refer to the inline file at a later time by using filename. If filename is not given, NMAKE gives the file a unique name in the directory specified by the TMP environment variable if it is defined. Otherwise, NMAKE creates a unique file name in the current directory.

The inline file can be temporary or permanent. If you do not specify otherwise, or if you specify the keyword NOKEEP, the inline file is temporary. Specify KEEP to retain the file.

The at sign (@) is not part of the NMAKE syntax but is the typical character used by utilities to designate a file as a response file.

Rational Developer for System z
PL/I for Windows, Version 8.0, Programming Guide