Command line options/commands/help infrastructure

1 files changed, 70 insertions, 0 deletions

diff --git a/bpkg/help.cxx b/bpkg/help.cxx
new file mode 100644
index 0000000..b63adbd
--- /dev/null
+++ b/bpkg/help.cxx
@@ -0,0 +1,70 @@
+// file      : bpkg/help.cxx -*- C++ -*-
+// copyright : Copyright (c) 2014-2015 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#include <bpkg/help>
+
+#include <cassert>
+#include <iostream>
+
+#include <bpkg/types>
+#include <bpkg/diagnostics>
+
+#include <bpkg/bpkg-options>
+#include <bpkg/help-options>
+
+using namespace std;
+
+namespace bpkg
+{
+  static void
+  help ()
+  {
+    ostream& o (cout);
+
+    o << "usage: bpkg --help" << endl
+      << "       bpkg --version" << endl
+      << "       bpkg [<common-options>] <command> [<command-options>] " <<
+      "[<command-args>]" << endl
+      << endl;
+
+    o << "The commands are:" << endl
+      << endl;
+
+    bpkg_commands::print_short_usage (o);
+    o << endl;
+
+    o << "The help topics are:" << endl
+      << endl;
+
+    bpkg_topics::print_short_usage (o);
+    o << endl;
+
+    o << "The common options are:" << endl
+      << endl;
+
+    common_options::print_short_usage (o);
+    o << endl;
+
+    o << "The common options can also be specified as part of the command-" <<
+      "specific ones."<< endl;
+  }
+
+  int
+  help (const help_options&, const string& t, void (*usage) (std::ostream&))
+  {
+    if (usage != nullptr)    // Command.
+      usage (cout);
+    else if (t.empty ())     // General help.
+      help ();
+    else if (t == "options") // Help topics.
+    {
+      common_options::print_long_usage (cout);
+    }
+    else
+      fail << "unknown bpkg command/help topic '" << t << "'" <<
+        info << "run 'bpkg help' for more information";
+
+    return 0;
+  }
+}