嵌入式 linux 下 通用 console（控制台） 的实现

前言：

当我们使用嵌入式linux 进行开发时，kernel 跑起来之后，我们希望能通过串口（标准输入、输出），在应用程序正在运行的过程中，进行一些调试工作，例如，对CPU一些寄存进行调整，以观测调整以后的结果，并且，当我们无法把我们的应用程序放在后台运行，那么我们就需要实现一个基础的控制台。

下文中的控制台，虽然简单，但完备的支持 上 下 左 右 backspace del 常用控制台操作，使用 上 下 键可以浏览已经输入过的命令（类似 doskey 这样的功能），支持 光标 左右移动 修改命令

一般我们在 main 函数最后 都会做 while(TRUE) sleep(1000) 这样 阻塞住主线程，用这个控制台的实现，替换这个过程，则应用程序可增加控制台应用功能，各部分的具体实现如下：

调用代码(main.c)：

#include <stdio.h>#include “app_console.h”int main(int argc, char *argv[]){// 之前的应用代码…………App_Console_Start(); return 0;}

控制台头文件(app_console.h)

#ifndef __APP_CONSOLE_H__#define __APP_CONSOLE_H__#ifdef __cplusplusextern “C”{#endif #include “type_def.h”void App_Console_Start();#ifdef __cplusplus}#endif#endif

控制台C文件(app_console.c)

#include “app_console.h”#include “ctype.h”#include “unistd.h”#include “app_test.h”// 说明// read write 使用的是 POSIX 的标准文件读写函数// unistd.h 包含了 STDIN_FILENO 等文件描述符的定义// ctype.h 包含了 isprint 函数的声明// 经过仔细考虑，决定不支持 ESC 键，因为ESC 键的键值为 0x1b 与 上下左右的键值重复// 但可以考虑按2下ESC清除本行输入// 对不可打印字符的处理仅限于以下已经列出的宏定义// change:// 放弃对 double ESC 的支持,因为可能出现按了 ESC 又按了 方向键 的情况// 则用户输入编码为 ‘/x1b’ ‘/x1b’ ‘[‘ ‘A’ (按了ESC 又按了上键)// change:// 为了将应用与控制台应用剥离，则将 #define MAX_CMD_LEN 512 房到 app_test.h 中定义// 二维数组作为参数进行传递时，需要明确第二个维度的大小，否则编译器无法正确定位地址#define KEY_BACKSPACE ‘/x08’ // back space #define KEY_DEL ‘/x7F’ // del #define KEY_ENTER ‘/x0A’ // 回车// 以下为 0x1b 开头的键值//#define KEY_DOUBLEESC “/x1B/x1B”// ESC//#define KEY_ARROW_UP “/x1B[A” // 上//#define KEY_ARROW_DOWN “/x1B[B” // 下//#define KEY_ARROW_LEFT “/x1B[D” // 左//#define KEY_ARROW_RIGHT “/x1B[C” // 右typedef enum {WKS_WAIT,WKS_RECV1B,WKS_UDLR,}T_WaitKeyState;#define MAX_CMD_HISTORY 32#define MAX_PAR_COUNT 16static char szPrompt[] = {“TR_Console> “};static T_WaitKeyState waitKeyState = WKS_WAIT;static char szCmdHistory[MAX_CMD_HISTORY][MAX_CMD_LEN];static char szCmdNow[MAX_CMD_LEN] = {0};static UINT32 nCmdIndex = 0;static UINT32 nCmdCursor = 0;static UINT32 nCmdInputCount = 0;static UINT32 nCmdInputCursor = 0;static void App_Console_ParseCmd(const char* pCmd);static UINT32 App_Console_ReadInput(char *input){U32 nRead=0;struct pollfd p;struct termio term,term_old;/* Get control of the terminal */ioctl(STDIN_FILENO,TCGETA,(void *)&term);term_old = term;term.c_lflag &= ~ICANON;term.c_lflag &= ~ECHO;ioctl(STDIN_FILENO,TCSETAW,(void *)&term);/* Get event we want to know */p.fd = STDIN_FILENO;p.events = POLLIN;/* If we receive one thing, get the byte now */if (poll(&p,1,-1)>0){if (p.revents==POLLIN){nRead=read(STDIN_FILENO,input,1);}}/* Purge the byte *//* tcflush(0,TCIOFLUSH); *//* Leave control */ioctl(STDIN_FILENO,TCSETAW,(void *)&term_old);return(nRead);}static void App_Console_BSChar(){char szTemp[3];szTemp[0] = ‘/b’;szTemp[1] = ‘ ‘;szTemp[2] = ‘/b’;write(STDOUT_FILENO,szTemp,3);}static void App_Console_OnPrintChar(char input){if(nCmdInputCount == MAX_CMD_LEN) return;if(nCmdInputCursor < nCmdInputCount) // 光标不在末尾{char szTemp[MAX_CMD_LEN] = {0};char* pCmd = szCmdNow;int nBackCount = nCmdInputCount-nCmdInputCursor;szTemp[0] = input;memcpy(&szTemp[1],&pCmd[nCmdInputCursor],nBackCount);write(STDOUT_FILENO,szTemp,nBackCount+1);memcpy(&pCmd[nCmdInputCursor],&szTemp,nBackCount+1);memset(szTemp,’/b’,nBackCount);write(STDOUT_FILENO,szTemp,nBackCount);}else{write(STDOUT_FILENO,&input,1);szCmdNow[nCmdInputCount] = input;}nCmdInputCursor++;nCmdInputCount++;}static void App_Console_OnBackspace(){if(nCmdInputCursor > 0){if(nCmdInputCursor == nCmdInputCount) // 光标在末尾App_Console_BSChar();else// 光标不在末尾{char szTemp[MAX_CMD_LEN] = {0};char* pCmd = szCmdNow;int nBackCount = nCmdInputCount-nCmdInputCursor;szTemp[0] = ‘/b’;memcpy(&szTemp[1],&pCmd[nCmdInputCursor],nBackCount);szTemp[nBackCount+1] = ‘ ‘;write(STDOUT_FILENO,szTemp,nBackCount+2);memcpy(&pCmd[nCmdInputCursor-1],&szTemp[1],nBackCount);memset(szTemp,’/b’,nBackCount+1);write(STDOUT_FILENO,szTemp,nBackCount+1);}nCmdInputCount –;nCmdInputCursor–;}}static void App_Console_OnDel(){if(nCmdInputCursor < nCmdInputCount) // 光标不在末尾{char szTemp[MAX_CMD_LEN] = {0};char* pCmd = szCmdNow;int nBackCount = nCmdInputCount-nCmdInputCursor-1;memcpy(szTemp,&pCmd[nCmdInputCursor+1],nBackCount);szTemp[nBackCount] = ‘ ‘;write(STDOUT_FILENO,szTemp,nBackCount+1);memcpy(&pCmd[nCmdInputCursor],szTemp,nBackCount);memset(szTemp,’/b’,nBackCount+1);write(STDOUT_FILENO,szTemp,nBackCount+1);nCmdInputCount–;}}static void App_Console_OnDoubleEsc(){if(nCmdInputCount > 0){char* pCmd = szCmdNow;// 将光标移动到最末尾while(nCmdInputCursor < nCmdInputCount){write(STDOUT_FILENO,&pCmd[nCmdInputCursor],1);nCmdInputCursor++;}// 清除所有输入的数据int i=0;for(i=0;i<nCmdInputCount;i++) App_Console_BSChar();nCmdInputCount = 0;nCmdInputCursor = 0;}}static void App_Console_OnUp(){if(nCmdCursor == 0) return;nCmdCursor –;// 清除掉现在所有的输入App_Console_OnDoubleEsc();char* pCmdHistory = &szCmdHistory[nCmdCursor][0];memcpy(szCmdNow,pCmdHistory,MAX_CMD_LEN);nCmdInputCount = strlen(szCmdNow);nCmdInputCursor= nCmdInputCount;write(STDOUT_FILENO,szCmdNow,nCmdInputCount);}static void App_Console_OnDown(){if(nCmdCursor >= (nCmdIndex-1)) return;nCmdCursor ++;// 清除掉现在所有的输入App_Console_OnDoubleEsc();char* pCmdHistory = &szCmdHistory[nCmdCursor][0];memcpy(szCmdNow,pCmdHistory,MAX_CMD_LEN);nCmdInputCount = strlen(szCmdNow);nCmdInputCursor= nCmdInputCount;write(STDOUT_FILENO,szCmdNow,nCmdInputCount);}static void App_Console_OnLeft(){if(nCmdInputCursor > 0){char c = ‘/b’;write(STDOUT_FILENO,&c,1);nCmdInputCursor–;}}static void App_Console_OnRight(){if(nCmdInputCursor < nCmdInputCount){char* pCmd = szCmdNow;char c = pCmd[nCmdInputCursor];write(STDOUT_FILENO,&c,1);nCmdInputCursor++;}}static void App_Console_OnEnter(){szCmdNow[nCmdInputCount] = ‘/0’;char szTemp[] = {“/r/n”};write(STDOUT_FILENO,szTemp,strlen(szTemp));nCmdInputCount = 0;nCmdInputCursor = 0;if(strlen(szCmdNow) == 0) return;if(nCmdIndex == MAX_CMD_HISTORY) // 命令队列满了，移动{char szTempCmd[MAX_CMD_HISTORY][MAX_CMD_LEN];memcpy(szTempCmd,&szCmdHistory[1][0],MAX_CMD_LEN*(MAX_CMD_HISTORY-1));memcpy(szCmdHistory,szTempCmd,MAX_CMD_LEN*(MAX_CMD_HISTORY-1));nCmdIndex = MAX_CMD_HISTORY-1;nCmdCursor = nCmdIndex;}memcpy(szCmdHistory[nCmdIndex],szCmdNow,MAX_CMD_LEN);nCmdIndex++;nCmdCursor = nCmdIndex;// 解析命令App_Console_ParseCmd(szCmdNow);}static void App_Console_CmdLoop(){BOOL bGetEnter = FALSE;while(TRUE){// 读取一个console输入UINT32 nReturn = 0;char input;nReturn = App_Console_ReadInput (&input);if(nReturn > 0){switch(waitKeyState){case WKS_WAIT :if(isprint(input))// 可打印字符App_Console_OnPrintChar(input);else{if(input == KEY_BACKSPACE)App_Console_OnBackspace();else if(input == KEY_DEL)App_Console_OnDel();else if(input == KEY_ENTER){App_Console_OnEnter();bGetEnter = TRUE;}else if(input == ‘/x1b’)waitKeyState = WKS_RECV1B;elsewaitKeyState = WKS_WAIT;}break;case WKS_RECV1B:if(input == ‘/x1b’) // 按了ESC 又按了方向键，或者是 ESC{//App_Console_OnDoubleEsc();waitKeyState = WKS_RECV1B;}else if(input == ‘[‘) //可能为 上下左右 4个键waitKeyState = WKS_UDLR;else//下面的情况为 按了 ESC 键之后，按了其他的键的处理{if(isprint(input)) App_Console_OnPrintChar(input);waitKeyState = WKS_WAIT;}break;case WKS_UDLR:if(input == ‘A’)// 上App_Console_OnUp();else if(input == ‘B’)// 下App_Console_OnDown();else if(input == ‘D’)// 左App_Console_OnLeft();else if(input == ‘C’)// 右App_Console_OnRight();else{if(isprint(input)) App_Console_OnPrintChar(input);}waitKeyState = WKS_WAIT;break;default:break;}}if(bGetEnter) {break;}}}void App_Console_Start(){// 清空 sdtout 缓冲 fflush(stdout);fflush(stdin);char szTemp[] = {“/r/nStart TR Console…/r/n/r/n”};write(STDOUT_FILENO,szTemp,strlen(szTemp));while(TRUE){write(STDOUT_FILENO,szPrompt,strlen(szPrompt));App_Console_CmdLoop();}}// 解析命令static void App_Console_ParseCmd(const char* pCmd){int length = strlen(pCmd); // 全部转小写int i=0;char szTempCmd[MAX_CMD_LEN];for (i=0; i < length; i++) szTempCmd[i] = tolower(pCmd[i]); // 将输入的命令各个 part 分开char szPart[MAX_PAR_COUNT][MAX_CMD_LEN];int nPartCount = 0;int nPartCursor = 0;int nCmdCursor = 0;memset(szPart,0,sizeof(szPart));while(TRUE){if(nCmdCursor == length) {if(nPartCursor > 0){nPartCount++;nPartCursor = 0;}break;}if( (szTempCmd[nCmdCursor] == ‘,’) || (szTempCmd[nCmdCursor] == ‘ ‘) ) // part 分割符{szPart[nPartCount][nPartCursor] = ‘/0’;nPartCount++;nPartCursor = 0;}else {szPart[nPartCount][nPartCursor] = szTempCmd[nCmdCursor];nPartCursor++;}nCmdCursor++;}App_Test_OnCmd(szPart,nPartCount);}

命令实现头文件(app_test.h)

#ifndef __APP_TEST_H__#define __APP_TEST_H__#ifdef __cplusplusextern “C”{#endif #include “type_def.h”#define MAX_CMD_LEN 512void App_Test_OnCmd(char szPart[][MAX_CMD_LEN],int nPartCount);#ifdef __cplusplus}#endif#endif

命令实现c文件(app_test.c)

#include “app_test.h”#include “stapp_main.h”#include “app_qam.h”#include “api_av.h”#include “api_video.h”#include “api_audio.h”#include “api_pcr.h”static void App_Test_OnHelp();static void App_Test_OnWriteReg8(char szPart[][MAX_CMD_LEN],int nPartCount);static void App_Test_OnReadReg8(char szPart[][MAX_CMD_LEN],int nPartCount);static void App_Test_OnQamConnect(char szPart[][MAX_CMD_LEN],int nPartCount);static void App_Test_OnAVPlayMpeg(char szPart[][MAX_CMD_LEN],int nPartCount);static void App_Test_OnAVStop();static void App_Test_OnVolumeSet(char szPart[][MAX_CMD_LEN],int nPartCount);static void App_Test_OnMute();static void App_Test_OnUnmute();static void App_Test_OnDENCRegDum();static void App_Test_OnDENCRegSet(char szPart[][MAX_CMD_LEN],int nPartCount);void App_Test_OnCmd(char szPart[][MAX_CMD_LEN],int nPartCount){// 这里处理私有的命令if(nPartCount == 0) return;if( strcmp(szPart[0],”help”) == 0){App_Test_OnHelp();}else if( strcmp(szPart[0],”writereg8″) == 0){if(nPartCount > 2) App_Test_OnWriteReg8(szPart,nPartCount);}else if( strcmp(szPart[0],”readreg8″) == 0){if(nPartCount > 1) App_Test_OnReadReg8(szPart,nPartCount);}else if( strcmp(szPart[0],”qamconnect”) == 0){if(nPartCount > 1) App_Test_OnQamConnect(szPart,nPartCount);}else if( strcmp(szPart[0],”avplaympeg”) == 0){if(nPartCount > 1) App_Test_OnAVPlayMpeg(szPart,nPartCount);}else if( strcmp(szPart[0],”avstop”) == 0){App_Test_OnAVStop();}else if( strcmp(szPart[0],”volumeset”) == 0){if(nPartCount > 1) App_Test_OnVolumeSet(szPart,nPartCount);}else if( strcmp(szPart[0],”mute”) == 0){App_Test_OnMute();}else if( strcmp(szPart[0],”unmute”) == 0){App_Test_OnUnmute();}else if( strcmp(szPart[0],”dencregdump”) == 0){App_Test_OnDENCRegDum();}else if( strcmp(szPart[0],”dencregset”) == 0){if(nPartCount > 1) App_Test_OnDENCRegSet(szPart,nPartCount);}}static void App_Test_OnHelp(){printf(“**************************************************************/n”);printf(“* Help PARAM MUST 0 MAX 0 Eg. help/n”);printf(“* WriteReg8 PARAM MUST 2 MAX 2 Eg. WriteReg8 0x1920C114 128/n”);printf(“* ReadReg8 PARAM MUST 1 MAX 1 Eg. ReadReg8 0x1920C114/n”);printf(“* QamConnect PARAM MUST 1 MAX 3 Eg. QamConnect 546000/n”);printf(“* AVPlayMpeg PARAM MUST 1 MAX 3 Eg. AVPlayMpeg 64 63 32/n”);printf(“* AVStop PARAM MUST 0 MAX 0 Eg. AVStop/n”);printf(“* VolumeSet PARAM MUST 1 MAX 1 Eg. VolumeSet 63/n”);printf(“* Mute PARAM MUST 0 MAX 0 Eg. Mute/n”);printf(“* Unmute PARAM MUST 0 MAX 0 Eg. Unmute/n”);printf(“* DENCRegDump PARAM MUST 0 MAX 0 Eg. DENCRegDump/n”);printf(“* DENCRegSet PARAM MUST 1 MAX 1 Eg. DENCRegSet 1/n”);printf(“*************************************************************/n”);}static void App_Test_OnWriteReg8(char szPart[][MAX_CMD_LEN],int nPartCount){char* pAddress = &szPart[1][0];char* pValue = &szPart[2][0];DWORD dwAddress = 0;UINT8 nValue = atoi(pValue);sscanf(pAddress,”0x%08x”,&dwAddress);SYS_WriteRegDev8(dwAddress,nValue);}static void App_Test_OnQamConnect(char szPart[][MAX_CMD_LEN],int nPartCount){char* pFreq = &szPart[1][0];UINT32 nFreq = atoi(pFreq);UINT32 nSymbolRate = 6875;T_DMD_Modulation nQAMMode = QAM_64;if(nPartCount > 2){char* pSymbolRate = &szPart[2][0];nSymbolRate = atoi(pSymbolRate);}if(nPartCount > 3){char* pQAMMode = &szPart[3][0];nQAMMode = atoi(pQAMMode);}App_Qam_Locking(TRUE,nFreq,nSymbolRate,nQAMMode);}static void App_Test_OnAVPlayMpeg(char szPart[][MAX_CMD_LEN],int nPartCount){UINT16 nVideoPid = 0xFFFF;UINT16 nAudioPid = 0xFFFF;UINT16 nPcrPid = 0xFFFF;char* pAudioPid = &szPart[1][0];nAudioPid = atoi(pAudioPid);if(nPartCount > 2){char* pVideoPid = &szPart[2][0];nVideoPid = atoi(pVideoPid);}if(nPartCount > 3){char* pPcr = &szPart[3][0];nPcrPid = atoi(pPcr);}Api_Av_Stop();Api_Av_Start(nAudioPid,STREAMTYPE_MP2A,nVideoPid,STREAMTYPE_MP2V,nPcrPid);}static void App_Test_OnVolumeSet(char szPart[][MAX_CMD_LEN],int nPartCount){UINT16 nVolume = 0; char* pVolume = &szPart[1][0];nVolume = atoi(pVolume);Api_Audio_Volume_Set(nVolume);}static void App_Test_OnMute(){Api_Audio_Mute();}static void App_Test_OnUnmute(){Api_Audio_Unmute();}static void App_Test_OnAVStop(){Api_Av_Stop();}static void App_Test_OnDENCRegDum(){printf(“* Brightness 0x1920C114 value is 0x%02x/n”,SYS_ReadRegDev8(0x1920C114));printf(“* Contrast 0x1920C118 value is 0x%02x/n”,SYS_ReadRegDev8(0x1920C118));printf(“* Saturation 0x1920C11c value is 0x%02x/n”,SYS_ReadRegDev8(0x1920C11c));printf(“* CHROMA_COEF0 0x1920C120 value is 0x%02x/n”,SYS_ReadRegDev8(0x1920C120));printf(“* CHROMA_COEF1 0x1920C124 value is 0x%02x/n”,SYS_ReadRegDev8(0x1920C124));printf(“* CHROMA_COEF2 0x1920C128 value is 0x%02x/n”,SYS_ReadRegDev8(0x1920C128));printf(“* CHROMA_COEF3 0x1920C12c value is 0x%02x/n”,SYS_ReadRegDev8(0x1920C12c));printf(“* CHROMA_COEF4 0x1920C130 value is 0x%02x/n”,SYS_ReadRegDev8(0x1920C130));printf(“* CHROMA_COEF5 0x1920C134 value is 0x%02x/n”,SYS_ReadRegDev8(0x1920C134));printf(“* CHROMA_COEF6 0x1920C138 value is 0x%02x/n”,SYS_ReadRegDev8(0x1920C138));printf(“* CHROMA_COEF7 0x1920C13c value is 0x%02x/n”,SYS_ReadRegDev8(0x1920C13c));printf(“* CHROMA_COEF8 0x1920C140 value is 0x%02x/n”,SYS_ReadRegDev8(0x1920C140));printf(“* LUM_COEF0 0x1920C148 value is 0x%02x/n”,SYS_ReadRegDev8(0x1920C148));printf(“* LUM_COEF1 0x1920C14c value is 0x%02x/n”,SYS_ReadRegDev8(0x1920C14c));printf(“* LUM_COEF2 0x1920C150 value is 0x%02x/n”,SYS_ReadRegDev8(0x1920C150));printf(“* LUM_COEF3 0x1920C154 value is 0x%02x/n”,SYS_ReadRegDev8(0x1920C154));printf(“* LUM_COEF4 0x1920C158 value is 0x%02x/n”,SYS_ReadRegDev8(0x1920C158));printf(“* LUM_COEF5 0x1920C15c value is 0x%02x/n”,SYS_ReadRegDev8(0x1920C15c));printf(“* LUM_COEF6 0x1920C160 value is 0x%02x/n”,SYS_ReadRegDev8(0x1920C160));printf(“* LUM_COEF7 0x1920C164 value is 0x%02x/n”,SYS_ReadRegDev8(0x1920C164));printf(“* LUM_COEF8 0x1920C168 value is 0x%02x/n”,SYS_ReadRegDev8(0x1920C168));printf(“* LUM_COEF9 0x1920C16c value is 0x%02x/n”,SYS_ReadRegDev8(0x1920C16c));printf(“* CFG9 0x1920C144 value is 0x%02x/n”,SYS_ReadRegDev8(0x1920C144));}static void App_Test_OnDENCRegSet(char szPart[][MAX_CMD_LEN],int nPartCount){UINT16 nScheme = 1; char* pScheme = &szPart[1][0];nScheme = atoi(pScheme);switch(nScheme){case 1:break;case 2:break;case 3:break;case 4:break;default:break;}}static void App_Test_OnReadReg8(char szPart[][MAX_CMD_LEN],int nPartCount){char* pAddress = &szPart[1][0];DWORD dwAddress = 0;sscanf(pAddress,”0x%08x”,&dwAddress);printf(“* 0x%08x value is 0x%02x/n”,dwAddress,SYS_ReadRegDev8(dwAddress));}

不敢接受失败的人，往往是那些追求完美的人，