/*
?*?????SD卡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SD卡/sdcard/song目錄中mp3歌曲
?*/
?
#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;
/*共享內存內容格式*/
/*|gradchild（孫子進程PID）?|+?|空一個字節|+?currentsong（當前播放列表的節點指針）|*/

/*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
**************************************************/
void?play（struct?song?*currentsong）
{
	pid_t?fd;
	char?*c_addr;
	char?*p;
	int?len;
	char?my_song[30]=“/udisk/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）?//孫子進程
		{
			/*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）;
??????????????????????/*運行madplay播放器，播放MP3*/
			execl（“/bin/madplay““madplay“my_songNULL）;//播放當前列表MP3音樂
			printf（“\n\n\n“）;
		}
		else?//子進程
		{
			/*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
**************************************************/
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?/udisk/song?>song_list“）;
	fd?=?fopen（“song_list““r“）;

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

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

	strncpy（p1->songnamelinestrlen（line））;
	head?=?p1;
	while（（size?=?getline（&line&lenfd））?!=?-1）?//從文件中讀取一行，直到出錯或者到文件尾EOF返回-1
	{	
		p2?=?p1;
		p1?=?（struct?song?*）malloc（sizeof（struct?song））;
		strncpy（p1->songnamelinestrlen（line））;
		

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2014-04-10?15:53??嵌入式作業\
?????目錄???????????0??2014-04-10?16:30??嵌入式作業\app\
?????文件??????????78??2011-01-03?01:58??嵌入式作業\app\Makefile
?????文件??????597674??2014-04-10?16:30??嵌入式作業\app\mp3_player
?????文件????????9003??2015-04-08?10:35??嵌入式作業\app\player.c
?????目錄???????????0??2014-04-10?15:52??嵌入式作業\bin\
?????文件??????103392??2011-09-02?15:52??嵌入式作業\bin\madplay
?????目錄???????????0??2014-04-10?15:52??嵌入式作業\driver\
?????文件?????????247??2011-01-03?01:48??嵌入式作業\driver\.int_key_drv.ko.cmd
?????文件???????14060??2011-01-03?01:48??嵌入式作業\driver\.int_key_drv.mod.o.cmd
?????文件???????22926??2011-01-03?01:48??嵌入式作業\driver\.int_key_drv.o.cmd
?????目錄???????????0??2014-04-10?15:52??嵌入式作業\driver\.tmp_versions\
?????文件??????????77??2011-01-03?01:48??嵌入式作業\driver\.tmp_versions\int_key_drv.mod
?????文件????????8537??2011-04-05?21:58??嵌入式作業\driver\int_key_drv.c
?????文件?????????390??2010-09-16?16:35??嵌入式作業\driver\Makefile
?????目錄???????????0??2014-04-10?15:52??嵌入式作業\madplay\
?????文件??????338143??2006-11-04?14:06??嵌入式作業\madplay\libid3tag-0.15.1b.tar.gz
?????文件??????502379??2006-11-04?14:10??嵌入式作業\madplay\libmad-0.15.1b.tar.gz
?????文件??????590929??2006-11-04?14:10??嵌入式作業\madplay\madplay-0.15.2b.tar.gz
?????文件?????2357056??2011-09-02?16:01??嵌入式作業\madplay\madplay.tar.gz
?????文件???????75616??2011-11-16?14:33??嵌入式作業\madplay\madplay移植到mini2440開發手冊-賀工.pdf
?????文件??????496597??2006-11-04?14:13??嵌入式作業\madplay\zlib-1.2.3.tar.tar
?????目錄???????????0??2014-04-10?15:54??嵌入式作業\song\
?????文件????14246016??2014-03-01?22:12??嵌入式作業\song\cannon.mp3
?????文件?????9630855??2014-03-01?21:40??嵌入式作業\song\catchmybreath.mp3
?????文件?????9322578??2014-02-27?22:26??嵌入式作業\song\innocence.mp3
?????文件????10093671??2014-02-26?20:16??嵌入式作業\song\ykzzldx.mp3
?????文件?????3852781??2014-02-27?22:26??嵌入式作業\song\zuijiasunyou.mp3