CommandLine: new command line parser

This implementation behaves mostly identical to old parser.
Few observable differences:
- There are no option groups (single group is used for all options)
- Option --stdout is hidden (it has been obsolete for a long time)
- MPD executable name (mpd) is hardcoded for simplicity

1 files changed, 88 insertions, 0 deletions

diff --git a/src/util/OptionParser.hxx b/src/util/OptionParser.hxx
new file mode 100644
index 000000000..74091bc29
--- /dev/null
+++ b/src/util/OptionParser.hxx
@@ -0,0 +1,88 @@
+/*
+ * Copyright (C) 2003-2013 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_UTIL_OPTIONPARSER_HXX
+#define MPD_UTIL_OPTIONPARSER_HXX
+
+#include <assert.h>
+
+class OptionDef;
+
+/**
+ * Command line option parser.
+ */
+class OptionParser
+{
+	int argc;
+	char **argv;
+	char *option;
+	char *option_raw;
+	bool is_long;
+public:
+	/**
+	 * Constructs #OptionParser.
+	 */
+	OptionParser(int _argc, char **_argv)
+		: argc(_argc - 1), argv(_argv + 1),
+		  option(nullptr), option_raw(nullptr), is_long(false) { }
+
+	/**
+	 * Checks if there are command line entries to process.
+	 */
+	bool HasEntries() const { return argc > 0; }
+
+	/**
+	 * Gets the last parsed option.
+	 */
+	char *GetOption() {
+		assert(option_raw != nullptr);
+		return option_raw;
+	}
+
+	/**
+	 * Checks if current option is a specified option.
+	 */
+	bool CheckOption(const OptionDef& opt);
+
+	/**
+	 * Checks if current option is a specified option
+	 * or specified alternative option.
+	 */
+	bool CheckOption(const OptionDef& opt, const OptionDef &alt_opt) {
+		return CheckOption(opt) || CheckOption(alt_opt);
+	}
+
+	/**
+	 * Parses current command line entry.
+	 * Returns true on success, false otherwise.
+	 * Regardless of result, advances current position to the next
+	 * command line entry. 
+	 */
+	bool ParseNext();
+
+	/**
+	 * Checks if specified string is a command line option.
+	 */
+	static bool IsOption(const char *s) {
+		assert(s != nullptr);
+		return s[0] == '-';
+	}
+};
+
+#endif