Add option -? for usage to Windows version of dotty

diff --git a/cmd/dotty/mswin32/dotty.c b/cmd/dotty/mswin32/dotty.c
index d92963c0b45eb63a939b2fcaf7ee017645e8df84..ddaea5f6b394bd3c3784393b52253a8444df3e4f 100644 (file)
--- a/cmd/dotty/mswin32/dotty.c
+++ b/cmd/dotty/mswin32/dotty.c
@@ -18,6 +18,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
+#include <shellapi.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 
@@ -41,6 +42,8 @@ int APIENTRY WinMain (
     char cmd[256];
     char *path;
     char *s;
+    int argc;
+    LPWSTR *argv;
 
     ZeroMemory (&si, sizeof(si));
     si.cb = sizeof(si);
@@ -56,6 +59,11 @@ int APIENTRY WinMain (
         if (!(path = buildpath ("lefty")))
             exit (1);
     }
+    argv = CommandLineToArgvW(lpCmdLine, &argc);
+    if (argc == 1 && strcmp(argv[0], "-?") == 0) {
+        fprintf(stderr, "usage: dotty [-V] [-lm (sync|async)] [-el (0|1)] <filename>\n");
+        exit(0);
+    }
     if (lpCmdLine[0] == 0)
         sprintf (
            cmd, "%s -e \"load('dotty.lefty');%sdotty.init();dotty.createviewandgraph(null,'file',null,null);txtview('off');\"",