reworked regex directory structure to match boost requirements.

[SVN r9752]

example/snippets/regex_split_example_2.cpp

@@ -0,0 +1,85 @@
+/*
+ *
+ * Copyright (c) 1998-2000
+ * Dr John Maddock
+ *
+ * Permission to use, copy, modify, distribute and sell this software
+ * and its documentation for any purpose is hereby granted without fee,
+ * provided that the above copyright notice appear in all copies and
+ * that both that copyright notice and this permission notice appear
+ * in supporting documentation.  Dr John Maddock makes no representations
+ * about the suitability of this software for any purpose.
+ * It is provided "as is" without express or implied warranty.
+ *
+ */
+
+ /*
+  *   LOCATION:    see http://www.boost.org for most recent version.
+  *   FILE         regex_split_example_2.cpp
+  *   VERSION      3.00
+  *   DESCRIPTION: regex_split example: spit out linked URL's.
+  */
+
+
+#include <list>
+#include <fstream>
+#include <iostream>
+#include <boost/regex.hpp>
+
+boost::regex e("<\\s*A\\s+[^>]*href\\s*=\\s*\"([^\"]*)\"",
+               boost::regbase::normal | boost::regbase::icase);
+
+void load_file(std::string& s, std::istream& is)
+{
+   s.erase();
+   //
+   // attempt to grow string buffer to match file size,
+   // this doesn't always work...
+   s.reserve(is.rdbuf()->in_avail());
+   char c;
+   while(is.get(c))
+   {
+      // use logarithmic growth stategy, in case
+      // in_avail (above) returned zero:
+      if(s.capacity() == s.size())
+         s.reserve(s.capacity() * 3);
+      s.append(1, c);
+   }
+}
+
+int main(int argc, char** argv)
+{
+   std::string s;
+   std::list<std::string> l;
+	int i;
+   for(i = 1; i < argc; ++i)
+   {
+      std::cout << "Findings URL's in " << argv[i] << ":" << std::endl;
+      s.erase();
+      std::ifstream is(argv[i]);
+      load_file(s, is);
+      boost::regex_split(std::back_inserter(l), s, e);
+      while(l.size())
+      {
+         s = *(l.begin());
+         l.pop_front();
+         std::cout << s << std::endl;
+      }
+   }
+   //
+   // alternative method:
+   // split one match at a time and output direct to
+   // cout via ostream_iterator<std::string>....
+   //
+   for(i = 1; i < argc; ++i)
+   {
+      std::cout << "Findings URL's in " << argv[i] << ":" << std::endl;
+      s.erase();
+      std::ifstream is(argv[i]);
+      load_file(s, is);
+      while(boost::regex_split(std::ostream_iterator<std::string>(std::cout), s, e, boost::match_default, 1)) std::cout << std::endl;
+   }
+
+   return 0;
+}
+