nmake と set

nmake では set は CMD.EXE ではなく、nmake 自身の組み込みコマンドらしい

test:
  set foo=ahaha
  echo %%foo%%

% は nmake用の Makefile ではファイル指定子であるため、２つ重ねなくてはいけない ※

$ nmake

Microsoft (R) Program Maintenance Utility Version 10.00.30319.01
Copyright (C) Microsoft Corporation.  All rights reserved.

        set foo=ahaha
        echo %foo%
ahaha

二重引用符の扱いについて、CMD.EXE との互換性はない

test:
  set "foo=ahaha"
  echo %%foo%%
  echo %%"foo%%

$ nmake

Microsoft (R) Program Maintenance Utility Version 10.00.30319.01
Copyright (C) Microsoft Corporation.  All rights reserved.

        set "foo=ahaha"
        echo %foo%
%foo%
        echo %"foo%
ahaha"

CMD.EXE の set を呼ぶには丸括弧で囲めば良い

test1:
  set GOOS=linux & go env GOOS

test2:
  ( set "GOOS=linux" & go env GOOS )

$ nmake test1

Microsoft (R) Program Maintenance Utility Version 10.00.30319.01
Copyright (C) Microsoft Corporation.  All rights reserved.                                                                                                                                  set GOOS=linux & go env GOOS
$ nmake test2

Microsoft (R) Program Maintenance Utility Version 10.00.30319.01
Copyright (C) Microsoft Corporation.  All rights reserved.                                                                                                                                  ( set "GOOS=linux" & go env GOOS )
linux