diff --git a/Source/makenssi.cpp b/Source/makenssi.cpp
index 6ea95896..7dc7f40e 100644
--- a/Source/makenssi.cpp
+++ b/Source/makenssi.cpp
@@ -93,13 +93,13 @@ int main(int argc, char **argv)
 
   build.setdirs(argv[0]);
 
-  if (argc > 1 && !stricmp(argv[1], "/VERSION"))
+  if (argc > 1 && !stricmp(argv[1], OPT_STR "VERSION"))
   {
     fprintf(g_output,NSIS_VERSION);
     fflush(g_output);
     return 0;
   }
-  if (argc > 1 && argv[1][0]=='/' && (argv[1][1]=='v' || argv[1][1]=='V'))
+  if (argc > 1 && argv[1][0]==OPT_C && (argv[1][1]=='v' || argv[1][1]=='V'))
   {
     tmpargpos++;
     if (argv[1][2] <= '2' && argv[1][2] >= '0')
@@ -110,7 +110,7 @@ int main(int argc, char **argv)
   
   if (!no_logo)
   {
-    if (argc > tmpargpos && argv[tmpargpos][0]=='/' && (argv[tmpargpos][1]=='o' || argv[tmpargpos][1]=='O') && argv[tmpargpos][2])
+    if (argc > tmpargpos && argv[tmpargpos][0]==OPT_C && (argv[tmpargpos][1]=='o' || argv[tmpargpos][1]=='O') && argv[tmpargpos][2])
     {
       g_output=fopen(argv[tmpargpos]+2,"w");
       if (!g_output) 
@@ -136,11 +136,11 @@ int main(int argc, char **argv)
   if (!g_output) g_output=stdout;
   while (argpos < argc)
   {
-    if (argv[argpos][0]=='/' && (argv[argpos][1]=='D' || argv[argpos][1]=='d') && argv[argpos][2])
+    if (argv[argpos][0] == OPT_C && strcmp(argv[argpos], "-"))
     {
-      char *p=argv[argpos]+2;
-      if (p[0])
+      if ((argv[argpos][1]=='D' || argv[argpos][1]=='d') && argv[argpos][2])
       {
+        char *p=argv[argpos]+2;
         char *s=strdup(p),*v;
         if (build.display_script) 
         {
@@ -152,117 +152,113 @@ int main(int argc, char **argv)
         build.define(s,v?v:"");
         free(s);
       }
-      else
+      else if ((argv[argpos][1]=='X' || argv[argpos][1]=='x') && argv[argpos][2])
       {
-        build.warning("command line /D requires argument (i.e. \"/Ddefine\"). ignored.");
-      }
-    }
-    else if (argv[argpos][0]=='/' && (argv[argpos][1]=='X' || argv[argpos][1]=='x') && argv[argpos][2])
-    {
-      if (build.process_oneline(argv[argpos]+2,"command line",argpos+1) != PS_OK)
-      {
-        return 1;
-      }
-      cmds_processed++;
-    }
-    else if (argv[argpos][0]=='/' && (argv[argpos][1]=='O' || argv[argpos][1]=='o') && argv[argpos][2])
-    {
-      if (!outputtried)
-      {
-        g_output=fopen(argv[argpos]+2,"w");
-        if (!g_output) 
+        if (build.process_oneline(argv[argpos]+2,"command line",argpos+1) != PS_OK)
         {
-          if (build.display_errors) printf("Error opening output log for writing. Using stdout.\n");
-          g_output=stdout;
+          return 1;
         }
-        outputtried=1;
+        cmds_processed++;
       }
-    }
-    else if (!stricmp(argv[argpos],"/NOCD")) do_cd=0;
-    else if (argv[argpos][0] == '/' && (argv[argpos][1] == 'V' || argv[argpos][1] == 'v') && 
-             argv[argpos][2] >= '0' && argv[argpos][2] <= '4' && !argv[argpos][3])
-    {
-      int v=argv[argpos][2]-'0';
-      build.display_script=v>3;
-      build.display_info=v>2;
-      build.display_warnings=v>1;
-      build.display_errors=v>0;
-      g_display_errors=build.display_errors;
-    }
-    else if (!stricmp(argv[argpos],"/NOCONFIG")) g_noconfig=1;
-    else if (!stricmp(argv[argpos],"/PAUSE")) g_dopause=1;
-    else if (!stricmp(argv[argpos],"/LICENSE")) 
-    {
-      if (build.display_info) 
+      else if ((argv[argpos][1]=='O' || argv[argpos][1]=='o') && argv[argpos][2])
       {
-        fprintf(g_output,"Copyright (C) 1999-2004 Nullsoft, Inc.\n\n"
-             "This license applies to everything in the NSIS package, except where otherwise noted.\n\n"
-             "This software is provided 'as-is', without any express or implied warranty.\n"
-             "In no event will the authors be held liable for any damages arising from the use\n"
-             "of this software.\n\n"
-             "Permission is granted to anyone to use this software for any purpose, including\n"
-             "commercial applications, and to alter it and redistribute it freely, subject to\n"
-             "the following restrictions:\n"
-             "  1. The origin of this software must not be misrepresented; you must not claim\n"
-             "     that you wrote the original software. If you use this software in a\n"
-             "     product, an acknowledgment in the product documentation would be\n"
-             "     appreciated but is not required.\n"
-             "  2. Altered source versions must be plainly marked as such, and must not be\n"
-             "     misrepresented as being the original software.\n"
-             "  3. This notice may not be removed or altered from any source distribution.\n\n");
-        fflush(g_output);
+        if (!outputtried)
+        {
+          g_output=fopen(argv[argpos]+2,"w");
+          if (!g_output) 
+          {
+            if (build.display_errors) printf("Error opening output log for writing. Using stdout.\n");
+            g_output=stdout;
+          }
+          outputtried=1;
+        }
       }
-      nousage++;
-    }
-    else if (!stricmp(argv[argpos],"/CMDHELP"))
-    {
-      if (argpos < argc-1)
-        build.print_help(argv[++argpos]);
-      else 
-        build.print_help(NULL);
-      nousage++;
-    }
-    else if (!stricmp(argv[argpos],"/NOTIFYHWND"))
-    {
+      else if (!stricmp(&argv[argpos][1],"NOCD")) do_cd=0;
+      else if ((argv[argpos][1] == 'V' || argv[argpos][1] == 'v') && 
+               argv[argpos][2] >= '0' && argv[argpos][2] <= '4' && !argv[argpos][3])
+      {
+        int v=argv[argpos][2]-'0';
+        build.display_script=v>3;
+        build.display_info=v>2;
+        build.display_warnings=v>1;
+        build.display_errors=v>0;
+        g_display_errors=build.display_errors;
+      }
+      else if (!stricmp(&argv[argpos][1],"NOCONFIG")) g_noconfig=1;
+      else if (!stricmp(&argv[argpos][1],"PAUSE")) g_dopause=1;
+      else if (!stricmp(&argv[argpos][1],"LICENSE")) 
+      {
+        if (build.display_info) 
+        {
+          fprintf(g_output,"Copyright (C) 1999-2004 Nullsoft, Inc.\n\n"
+               "This license applies to everything in the NSIS package, except where otherwise\nnoted.\n\n"
+               "This software is provided 'as-is', without any express or implied warranty.\n"
+               "In no event will the authors be held liable for any damages arising from the\n"
+               "use of this software.\n\n"
+               "Permission is granted to anyone to use this software for any purpose, including\n"
+               "commercial applications, and to alter it and redistribute it freely, subject to\n"
+               "the following restrictions:\n"
+               "  1. The origin of this software must not be misrepresented; you must not claim\n"
+               "     that you wrote the original software. If you use this software in a\n"
+               "     product, an acknowledgment in the product documentation would be\n"
+               "     appreciated but is not required.\n"
+               "  2. Altered source versions must be plainly marked as such, and must not be\n"
+               "     misrepresented as being the original software.\n"
+               "  3. This notice may not be removed or altered from any source distribution.\n\n");
+          fflush(g_output);
+        }
+        nousage++;
+      }
+      else if (!stricmp(&argv[argpos][1],"CMDHELP"))
+      {
+        if (argpos < argc-1)
+          build.print_help(argv[++argpos]);
+        else
+          build.print_help(NULL);
+        nousage++;
+      }
+      else if (!stricmp(&argv[argpos][1],"NOTIFYHWND"))
+      {
 #ifdef _WIN32
-      build.notify_hwnd=(HWND)atol(argv[++argpos]);
-      if (!IsWindow(build.notify_hwnd))
-        build.notify_hwnd=0;
+        build.notify_hwnd=(HWND)atol(argv[++argpos]);
+        if (!IsWindow(build.notify_hwnd))
+          build.notify_hwnd=0;
 #else
-      argpos++;
-      build.warning("/NOTIFYHWND is disabled for non Win32 platforms.");
+        argpos++;
+        build.warning(OPT_STR "NOTIFYHWND is disabled for non Win32 platforms.");
 #endif
-    }
-    else if (!stricmp(argv[argpos],"/HDRINFO"))
-    {
-      if (build.display_info) 
-      {
-        fprintf(g_output,"Size of zlib EXE header is %d bytes.\n",zlib_exehead_size);
-        fprintf(g_output,"Size of bzip2 EXE header is %d bytes.\n",bzip2_exehead_size);
-        fprintf(g_output,"Size of lzma EXE header is %d bytes.\n",lzma_exehead_size);
-        fprintf(g_output,"Size of first header is %d bytes.\n",sizeof(firstheader));
-        fprintf(g_output,"Size of main header is %d bytes.\n",sizeof(header));
-        fprintf(g_output,"Size of each section is %d bytes.\n",sizeof(section));
-        fprintf(g_output,"Size of each page is %d bytes.\n",sizeof(page));
-        fprintf(g_output,"Size of each instruction is %d bytes.\n",sizeof(entry));
-        int x=build.definedlist.getnum();
-        fprintf(g_output,"\nDefined symbols: ");
-        for (int i=0; i<x; i++)
-        {
-          fprintf(g_output,"%s",build.definedlist.getname(i));
-          char *p=build.definedlist.getvalue(i);
-          if (*p) fprintf(g_output,"=%s",p);
-          if (i<x-1) fprintf(g_output,",");
-        }
-        if (!x) fprintf(g_output,"none");
-        fprintf(g_output,"\n");
-        fflush(g_output);
       }
-      nousage++;
+      else if (!stricmp(&argv[argpos][1],"HDRINFO"))
+      {
+        if (build.display_info)
+        {
+          fprintf(g_output,"Size of zlib EXE header is %d bytes.\n",zlib_exehead_size);
+          fprintf(g_output,"Size of bzip2 EXE header is %d bytes.\n",bzip2_exehead_size);
+          fprintf(g_output,"Size of lzma EXE header is %d bytes.\n",lzma_exehead_size);
+          fprintf(g_output,"Size of first header is %d bytes.\n",sizeof(firstheader));
+          fprintf(g_output,"Size of main header is %d bytes.\n",sizeof(header));
+          fprintf(g_output,"Size of each section is %d bytes.\n",sizeof(section));
+          fprintf(g_output,"Size of each page is %d bytes.\n",sizeof(page));
+          fprintf(g_output,"Size of each instruction is %d bytes.\n",sizeof(entry));
+          int x=build.definedlist.getnum();
+          fprintf(g_output,"\nDefined symbols: ");
+          for (int i=0; i<x; i++)
+          {
+            fprintf(g_output,"%s",build.definedlist.getname(i));
+            char *p=build.definedlist.getvalue(i);
+            if (*p) fprintf(g_output,"=%s",p);
+            if (i<x-1) fprintf(g_output,",");
+          }
+          if (!x) fprintf(g_output,"none");
+          fprintf(g_output,"\n");
+          fflush(g_output);
+        }
+        nousage++;
+      }
+      else break;
     }
-    else 
+    else
     {
-      if (argv[argpos][0]=='/') break;
       files_processed++;
       if (!strcmp(argv[argpos],"-")) g_dopause=0;
       if (!g_noconfig)
@@ -387,17 +383,17 @@ int main(int argc, char **argv)
       fprintf(g_output,"Usage:\n"
              "  makensis [options] [script.nsi | - [...]]\n"
              "   options are:\n"
-             "    /CMDHELP item prints out help for 'item', or lists all commands\n"
-             "    /HDRINFO prints information about what options makensis was compiled with\n"
-             "    /LICENSE prints the makensis software license\n");
-      fprintf(g_output,
-             "    /Vx verbosity where x is 4=all,3=no script,2=no info,1=no warnings,0=none\n"
-             "    /Ofile specifies a text file to log compiler output (default is stdout)\n"
-             "    /PAUSE pauses after execution\n"
-             "    /NOCONFIG disables inclusion of <path to makensis.exe>\\nsisconf.nsh\n"
-             "    /NOCD disabled the current directory change to that of the .nsi file\n"
-             "    /Ddefine[=value] defines the symbol \"define\" for the script [to value]\n"
-             "    /Xscriptcmd executes scriptcmd in script (i.e. \"/XOutFile poop.exe\")\n"
+             "    " OPT_STR "CMDHELP item prints out help for 'item', or lists all commands\n"
+             "    " OPT_STR "HDRINFO prints information about what options makensis was compiled with\n"
+             "    " OPT_STR "LICENSE prints the makensis software license\n"
+             "    " OPT_STR "VERSION prints the makensis version and exits\n"
+             "    " OPT_STR "Vx verbosity where x is 4=all,3=no script,2=no info,1=no warnings,0=none\n"
+             "    " OPT_STR "Ofile specifies a text file to log compiler output (default is stdout)\n"
+             "    " OPT_STR "PAUSE pauses after execution\n"
+             "    " OPT_STR "NOCONFIG disables inclusion of <path to makensis.exe>" PLATFORM_PATH_SEPARATOR_STR "nsisconf.nsh\n"
+             "    " OPT_STR "NOCD disabled the current directory change to that of the .nsi file\n"
+             "    " OPT_STR "Ddefine[=value] defines the symbol \"define\" for the script [to value]\n"
+             "    " OPT_STR "Xscriptcmd executes scriptcmd in script (i.e. \"" OPT_STR "XOutFile poop.exe\")\n"
              "   for script file name, you can use - to read from the standard input\n");
       fflush(g_output);
     }