Feature #546

- Added feature #546, which is a 'count' command that counts tasks, and is
  intended to help scripts that manipulate task output.
- Added unit tests.
- Added man page description.

src/command.cpp

@@ -2032,6 +2032,37 @@ int handleDuplicate (std::string& outs)
   return rc;
 }
 
+////////////////////////////////////////////////////////////////////////////////
+int handleCount (std::string& outs)
+{
+  int rc = 0;
+
+  if (context.hooks.trigger ("pre-count-command"))
+  {
+    // Scan the pending tasks, applying any filter.
+    std::vector <Task> tasks;
+    context.tdb.lock (context.config.getBoolean ("locking"));
+    handleRecurrence ();
+    context.tdb.load (tasks, context.filter);
+    context.tdb.commit ();
+    context.tdb.unlock ();
+
+    // Find number of matching tasks.  Skip recurring parent tasks.
+    int count = 0;
+    std::vector <Task>::iterator it;
+    for (it = tasks.begin (); it != tasks.end (); ++it)
+      if (it->getStatus () != Task::recurring)
+        ++count;
+
+    std::stringstream out;
+    out << count << "\n";
+    outs = out.str ();
+    context.hooks.trigger ("post-count-command");
+  }
+
+  return rc;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 #ifdef FEATURE_SHELL
 void handleShell ()