added examples/howto-parse-args.cxx

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@7727 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

examples/Makefile

@@ -1,6 +1,7 @@
 include ../makeinclude
 
 ALL = howto-add_fd-and-popen$(EXEEXT) \
+      howto-parse-args$(EXEEXT) \
       tabs-simple$(EXEEXT) \
       tree-simple$(EXEEXT) \
       wizard-simple$(EXEEXT)

examples/howto-parse-args.cxx

@@ -0,0 +1,86 @@
+//
+// "$Id:$"
+//
+//     How to parse command line arguments - Duncan Gibson 2010-10-23
+//     First posted in http://www.fltk.org/newsgroups.php?gfltk.general+v:31449
+//
+//     Shows how to decode additional command line arguments using Fl::args()
+//     on top of the "standard" options used by the toolkit itself.
+//
+// Copyright 1998-2010 by Bill Spitzak and others.
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Library General Public
+// License as published by the Free Software Foundation; either
+// version 2 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Library General Public License for more details.
+//
+// You should have received a copy of the GNU Library General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+// USA.
+//
+// Please report all bugs and problems on the following page:
+//
+//     http://www.fltk.org/str.php
+//
+#include <FL/Fl.H>
+#include <FL/Fl_Box.H>
+#include <FL/Fl_Window.H>
+#include "stdio.h"
+#include "string.h"
+
+int helpFlag = 0;
+char *optionString = 0;
+
+int arg(int argc, char **argv, int &i)
+{
+  if (strcmp("-h", argv[i]) == 0 || strcmp("--help", argv[i]) == 0) {
+    helpFlag = 1;
+    i += 1;
+    return 1;
+  }
+  if (strcmp("-o", argv[i]) == 0 || strcmp("--option", argv[i]) == 0) {
+    if (i < argc-1 && argv[i+1] != 0) {
+      optionString = argv[i+1];
+      i += 2;
+      return 2;
+    }
+  }
+  return 0;
+}
+
+int main(int argc, char** argv)
+{
+  int i = 1;
+  if (Fl::args(argc, argv, i, arg) < argc)
+    // note the concatenated strings to give a single format string!
+    Fl::fatal("error: unknown option: %s\n"
+              "usage: %s [options]\n"
+              " -h | --help     : print extended help message\n"
+              " -o | --option # : example option with parameter\n"
+              " plus standard fltk options\n",
+              argv[i], argv[0]);
+  if (helpFlag)
+    Fl::fatal("usage: %s [options]\n"
+              " -h | --help     : print extended help message\n"
+              " -o | --option # : example option with parameter\n"
+              " plus standard fltk options:\n"
+              "%s\n",
+              argv[0], Fl::help);
+
+  Fl_Window* mainWin = new Fl_Window(300, 200);
+  Fl_Box* textBox = new Fl_Box(0, 0, 300, 200);
+  if (optionString != 0)
+    textBox->label(optionString);
+  mainWin->show(argc, argv);
+  return Fl::run();
+}
+
+//
+// End of "$Id:$".
+//