This is a bin\R.exe + bin\Rscript.exe bug. On Windows, where the system call to create a process only takes one command line string instead of an array of command line parameters[0] (and the C runtimes usually call CommandLineToArgvW[1] behind the scenes to get an array back), execv() does nothing to prepare a properly-quoted command line and just concatenates its arguments[2]. Moreover, Windows version of execv() is effectively undocumented[3], nor there is any information about the suggested replacement[4]. (You can call it a Windows bug instead.)
Short file names are not a guaranteed solution, because they may not be available at all on some filesystems[5] (which is how this error has been encountered). In the general case, "argument quoting hell"[6] is unavoidable on Windows, but the code from [2] implements the proper conversion from an array of strings to a single quoted command line, ready to be parsed by the launched process. char* getRHOME(int m) in src/gnuwin32/rhome.c tries to return a short path (assuming it won't contain spaces). This is used by rcmdfn() from src/gnuwin32/front-ends/rcmdfn.c to system() a command line built with no quoting, causing the error. rcmdfn() is called from src/gnuwin32/front-ends/R.c, which seems to contain the entry point for R\R-3.3.3\bin\R.exe. Fortunately, in src/unix/Rscript.c the whole mess seems to be avoided by having it directly include rterm.c and then call AppMain() on Windows, passing the command line parameter array. Same goes for src/gnuwin32/front-ends/graphappmain.c. The corresponding executables reside in the architecture-specific subdirectory of ...\bin\. So if you run Rgui.exe, Rterm.exe or Rscript.exe from R-3.3.3\bin\i386 instead of R-3.3.3\bin, no extra cmd.exe processes should be spawned and the badly-formed system() should be avoided. -- Best regards, Ivan [0] https://docs.microsoft.com/en-us/windows/desktop/api/processthreadsapi/nf-processthreadsapi-createprocessa That's probably for historical reasons, because Win32 API wanted to stay mostly source-compatible with Win16 API, and Win16 API may have evolved from DOS system calls, where the command line was, indeed, a single string pointer. [1] https://docs.microsoft.com/en-us/windows/desktop/api/shellapi/nf-shellapi-commandlinetoargvw [2] https://blogs.msdn.microsoft.com/twistylittlepassagesallalike/2011/04/23/everyone-quotes-command-line-arguments-the-wrong-way/ [3] https://docs.microsoft.com/en-us/previous-versions/visualstudio/visual-studio-2012/ms235416(v=vs.110) [4] https://docs.microsoft.com/en-us/cpp/c-runtime-library/exec-wexec-functions?view=vs-2017 [5] https://blogs.msdn.microsoft.com/oldnewthing/20181004-00/?p=99895 [6] quoted from Rscript.c ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
