I have a Makefile of Unix origin which contains some _very_ long command lines. Will it work with djgpp?

Yes and yes. DJGPP supports several methods of passing command-line arguments which allow to work around the DOS 127-character limit. These are:

• The !proxy method. If you invoke the program from within another djgpp program (like make or gcc compilation driver), it gets the address of the memory block where the actual command line is stored. The go32 which gets control before your program is run will detect this and use that info to retrieve the command-line arguments.

  This method is suitable only for invoking djgpp programs from other djgpp programs. You don't have to do anything special to use this method, it is all done automagically for you by the spawnXX() and execXX() family of library functions on the parent program side, and by go32 on the child side.

• The GNUish MS-DOS method. This was invented when some GNU programs were ported to 16-bit MS-DOS compilers as part of GNUish MS-DOS project. The arguments are passed through the environment variables which are called _argc, _argv0, _argv1, etc. Note that the variables' names are indeed all-lowercase, which means you cannot use this method from DOS command.com prompt.

  This method is suitable for invoking djgpp programs from GNUish ports of GNU software, like real-mode make program found on SimTel mirrors, some ports of Unix shells (like ms_sh), etc. You can also use it in your real-mode programs by creating the above environment variables.

  Note that djgpp programs can only use this method, but they don't generate GNUish-style environment variables, so you cannot use this method to pass long command lines between djgpp and non-djgpp programs, unless your program explicitly creates these variables before calling execXX() or spawnXX().

• The response file method. Any argument which starts with a @ character (like in ``myprog @file'') will cause the named file to be read and its contents used as command-line arguments, like in many DOS-based compilers and linkers. If you invoke your djgpp program from DOS command line, this would be the only method available for you to pass long command lines (like when calling gawk or sed without -f option).

  Note that this method makes @ special when it is the first (or the only) character of a command-line argument, which should be escape-protected if you want to use it verbatim.