new feature: command line switch for displaying now playing song

src/helpers.cpp

@@ -44,6 +44,7 @@ bool ConnectToMPD()
 void ParseArgv(int argc, char **argv)
 {
 	bool quit = 0;
+	std::string now_playing_format = "{{(%l) }{{%a - }%t}}|{%f}}";
 	
 	for (int i = 1; i < argc; ++i)
 	{
@@ -85,6 +86,8 @@ void ParseArgv(int argc, char **argv)
 			<< "  -p, --port                connect to server at port [6600]\n"
 			<< "  -?, --help                show this help message\n"
 			<< "  -v, --version             display version information\n\n"
+			<< "  --now-playing             display now playing song [" << now_playing_format << "\n"
+			<< "\n"
 			<< "  play                      start playing\n"
 			<< "  pause                     pause the currently playing song\n"
 			<< "  toggle                    toggle play/pause mode\n"
@@ -99,7 +102,24 @@ void ParseArgv(int argc, char **argv)
 		if (!ConnectToMPD())
 			exit(0);
 		
-		if (!strcmp(argv[i], "play"))
+		if (!strcmp(argv[i], "--now-playing"))
+		{
+			Mpd.UpdateStatus();
+			if (Mpd.GetState() > psStop)
+			{
+				if (argc > ++i)
+				{
+					// apply additional pair of braces
+					now_playing_format = "{";
+					now_playing_format += argv[i];
+					now_playing_format += "}";
+					MPD::Song::ValidateFormat("now-playing format", now_playing_format);
+				}
+				std::cout << Mpd.GetCurrentSong().toString(now_playing_format) << "\n";
+			}
+			quit = 1;
+		}
+		else if (!strcmp(argv[i], "play"))
 		{
 			Mpd.Play();
 			quit = 1;

src/settings.cpp

@@ -24,7 +24,6 @@
 # include <sys/stat.h>
 #endif // WIN32
 #include <fstream>
-#include <stdexcept>
 
 #include "global.h"
 #include "helpers.h"
@@ -62,20 +61,6 @@ namespace
 		key[1] = !two.empty() && two[0] == '\'' ? two[1] : (atoi(two.c_str()) == 0 ? null_key : atoi(two.c_str()));
 	}
 	
-	void ValidateSongFormat(const std::string &type, const std::string &s)
-	{
-		int braces = 0;
-		for (std::string::const_iterator it = s.begin(); it != s.end(); ++it)
-		{
-			if (*it == '{')
-				++braces;
-			else if (*it == '}')
-				--braces;
-		}
-		if (braces)
-			throw std::runtime_error(type + ": number of opening and closing braces does not equal!");
-	}
-	
 	Border IntoBorder(const std::string &color)
 	{
 		return Border(IntoColor(color));
@@ -538,7 +523,7 @@ void ReadConfiguration(ncmpcpp_config &conf)
 			{
 				if (!v.empty())
 				{
-					ValidateSongFormat("song_list_format", v);
+					MPD::Song::ValidateFormat("song_list_format", v);
 					conf.song_list_format = '{';
 					conf.song_list_format += v;
 					conf.song_list_format += '}';
@@ -553,7 +538,7 @@ void ReadConfiguration(ncmpcpp_config &conf)
 			{
 				if (!v.empty())
 				{
-					ValidateSongFormat("song_status_format", v);
+					MPD::Song::ValidateFormat("song_status_format", v);
 					conf.song_status_format = '{';
 					conf.song_status_format += v;
 					conf.song_status_format += '}';
@@ -563,7 +548,7 @@ void ReadConfiguration(ncmpcpp_config &conf)
 			{
 				if (!v.empty())
 				{
-					ValidateSongFormat("song_library_format", v);
+					MPD::Song::ValidateFormat("song_library_format", v);
 					conf.song_library_format = '{';
 					conf.song_library_format += v;
 					conf.song_library_format += '}';
@@ -573,7 +558,7 @@ void ReadConfiguration(ncmpcpp_config &conf)
 			{
 				if (!v.empty())
 				{
-					ValidateSongFormat("tag_editor_album_format", v);
+					MPD::Song::ValidateFormat("tag_editor_album_format", v);
 					conf.tag_editor_album_format = '{';
 					conf.tag_editor_album_format += v;
 					conf.tag_editor_album_format += '}';
@@ -598,7 +583,7 @@ void ReadConfiguration(ncmpcpp_config &conf)
 			{
 				if (!v.empty())
 				{
-					ValidateSongFormat("alternative_header_first_line_format", v);
+					MPD::Song::ValidateFormat("alternative_header_first_line_format", v);
 					conf.new_header_first_line = '{';
 					conf.new_header_first_line += v;
 					conf.new_header_first_line += '}';
@@ -608,7 +593,7 @@ void ReadConfiguration(ncmpcpp_config &conf)
 			{
 				if (!v.empty())
 				{
-					ValidateSongFormat("alternative_header_second_line_format", v);
+					MPD::Song::ValidateFormat("alternative_header_second_line_format", v);
 					conf.new_header_second_line = '{';
 					conf.new_header_second_line += v;
 					conf.new_header_second_line += '}';
@@ -790,7 +775,7 @@ void ReadConfiguration(ncmpcpp_config &conf)
 			{
 				if (!v.empty())
 				{
-					ValidateSongFormat("song_window_title_format", v);
+					MPD::Song::ValidateFormat("song_window_title_format", v);
 					conf.song_window_title_format = '{';
 					conf.song_window_title_format += v;
 					conf.song_window_title_format += '}';

src/song.cpp

@@ -25,6 +25,7 @@
 #include <cstring>
 #include <iomanip>
 #include <sstream>
+#include <stdexcept>
 
 #include "charset.h"
 #include "misc.h"
@@ -446,6 +447,20 @@ std::string MPD::Song::ShowTime(int length)
 	return ss.str();
 }
 
+void MPD::Song::ValidateFormat(const std::string &type, const std::string &s)
+{
+	int braces = 0;
+	for (std::string::const_iterator it = s.begin(); it != s.end(); ++it)
+	{
+		if (*it == '{')
+			++braces;
+		else if (*it == '}')
+			--braces;
+	}
+	if (braces)
+		throw std::runtime_error(type + ": number of opening and closing braces does not equal!");
+}
+
 void MPD::Song::SetHashAndSlash()
 {
 	if (!itsSong->file)

src/song.h

@@ -92,6 +92,8 @@ namespace MPD
 			Song &operator=(const Song &);
 			
 			static std::string ShowTime(int);
+			static void ValidateFormat(const std::string &type, const std::string &format);
+			
 		private:
 			void SetHashAndSlash();
 			std::string ParseFormat(std::string::const_iterator &it) const;