/*
?*?????mp3播放器控制程序
?*	???功能：
?*		?k1:播放、暫停
?*		?k2:停止播放
?*		?k3:上一首
?*		?k4:下一首
?*?????附加：歌曲自動循環播放
?*/
#include?
#include?
#include?
#include?
#include?
#include?
#include?
#include?
#include?
#include?
#include?
#include?
#include?
#include?
#include?

/*共享內存申請標記*/
#define?PERM?S_IRUSR|S_IWUSR													

/*雙向循環列表：存放歌曲名*/
struct?song				
{
	char?songname[20];
	struct?song?*prev;
	struct?song?*next;
};

/*孫子進程id號*/
pid_t?gradchild;

/*子進程id號*/
pid_t?pid;

/*共享內存描述標記*/
int?shmid;

char?*p_addr;

/*播放標記*/
int?first_key=1;
int?play_flag=0;

/*************************************************
Function?name:?play
Parameter????:?struct?song?*
Description	?:?播放函數
Return		?:?void
Argument?????:?void
Autor?&?date?:?ada?091207
**************************************************/
void?play（struct?song?*currentsong）
{
	pid_t?fd;
	char?*c_addr;
	char?*p;
	int?len;
	char?my_song[30]=“/mp3/song/“;
	while（currentsong）
	{
		/*創建子進程，即孫子進程*/
		fd?=?fork（）;
		if（fd?==?-1）
		{	
			perror（“fork“）;
			exit（1）;
		}
		else?if（fd?==?0）
		{
			/*把歌曲名加上根路徑*/
			strcat（my_songcurrentsong->songname）;
			p?=?my_song;
			len?=?strlen（p）;

			/*去掉文件名最后的‘\n‘*/
			my_song[len-1]=‘\0‘;

			printf（“THIS?SONG?IS?%s\n“my_song）;
			execl（“/mp3/madplay““madplay“my_songNULL）;
			printf（“\n\n\n“）;
		}
		else
		{
			/*內存映射*/
			c_addr?=?shmat（shmid00）;

			/*把孫子進程的id和當前播放歌曲的節點指針傳入共享內存*/
			memcpy（c_addr&fdsizeof（pid_t））;
			memcpy（c_addr?+?sizeof（pid_t）+1¤tsong4）;
			/*使用wait阻塞孫子進程，直到孫子進程播放完才能被喚醒；
			??當被喚醒時，表示播放MP3期間沒有按鍵按下，則繼續順序播放下一首MP3*/
			if（fd?==?wait（NULL））
			{
				currentsong?=?currentsong->next;
				printf（“THE?NEXT?SONG?IS?%s\n“currentsong->songname）;
			}
		}
	}
}

/*************************************************
Function?name:?creat_song_list
Parameter????:?void
Description	?:?創建歌曲名的雙向循環鏈表
Return		?:?struct?song?*
Argument?????:?void
Autor?&?date?:?ada?09.12.07
**************************************************/
struct?song?*creat_song_list（void）
{	
	FILE?*fd;
	size_t?size;
	size_t?len;
	char?*line?=?NULL;
	struct?song?*head;
	struct?song?*p1;
	struct?song?*p2;
	system（“ls?/mp3/song?>song_list“）;
	fd?=?fopen（“song_list““r“）;

	p1?=?（struct?song?*）malloc（sizeof（struct?song））;

	printf（“==================================song?list=====================================\n“）;
	system（“ls?/mp3/song“）;	
	printf（“\n“）;
	printf（“================================================================================\n“）;
	size?=?getline（&line&lenfd）;

	strncpy（p1->songnamelinestrlen（line））;
	head?=?p1;
	while（（size?=?getline（&line&lenfd））?!=?-1）
	{	
		p2?=?p1;
		p1?=?（struct?song?*）malloc（sizeof（struct?song））;
		strncpy（p1->songnamelinestrlen（line））;
		p2->next?=?p1;
		p1->prev?=?p2;	
	}
	p1->next?=?head;
	head->prev?=?p1;
	p1?=?NULL;
	p2?=?NULL;
	system（“rm?-rf?song_list“）;
	return?head;
}
/**********

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2013-07-05?00:03??mp3player\
?????文件????????2764??2013-07-05?00:06??mp3player\README.txt
?????目錄???????????0??2013-07-05?00:02??mp3player\app\
?????文件?????????120??2013-05-27?20:22??mp3player\app\Makefile
?????文件???????13533??2013-05-27?20:22??mp3player\app\mp3player
?????文件????????8773??2013-05-27?20:11??mp3player\app\mp3player.c
?????目錄???????????0??2013-07-05?00:02??mp3player\driver\
?????文件?????????317??2013-05-27?20:25??mp3player\driver\.mini2440_buttons.ko.cmd
?????文件???????15956??2013-05-27?20:25??mp3player\driver\.mini2440_buttons.mod.o.cmd
?????文件???????24781??2013-05-27?20:25??mp3player\driver\.mini2440_buttons.o.cmd
?????目錄???????????0??2013-07-05?00:08??mp3player\driver\.tmp_versions\
?????文件?????????240??2013-05-27?20:38??mp3player\driver\Makefile
?????文件????????4963??2013-05-27?20:08??mp3player\driver\mini2440_buttons.c
?????文件???????????0??2013-05-27?20:39??mp3player\driver\modules.order
?????目錄???????????0??2013-07-05?00:08??mp3player\kernel\
?????目錄???????????0??2013-07-05?00:02??mp3player\lib\
?????文件??????338143??2013-05-27?20:09??mp3player\lib\libid3tag-0.15.1b.tar.gz
?????文件??????502379??2013-05-27?20:09??mp3player\lib\libmad-0.15.1b.tar.gz
?????文件??????215028??2013-05-27?20:09??mp3player\lib\mad-0.10.1b.tar.gz
?????文件??????590929??2013-05-27?20:09??mp3player\lib\madplay-0.15.2b.tar.gz
?????文件??????181144??2013-05-27?20:09??mp3player\lib\zlib-1.1.4.tar.gz