Linux|Linux 串口一次性read接收不定长的数据（非阻塞,非延时）程序分析 Linux串口一次性read接收不定长

二话不说，直接上代码。

/*********************Copyright(c)************************************************************************ **Guangzhou ZHIYUAN electronics Co.,LTD ** **http://www.embedtools.com ** **-------File Info--------------------------------------------------------------------------------------- ** File Name:serial-test.c ** Latest modified Data:2008-05-19 ** Latest Version:v1.1 ** Description:NONE ** **-------------------------------------------------------------------------------------------------------- ** Create By:zhuguojun ** Create date:2008-05-19 ** Version:v1.1 ** Descriptions:epc-8000's long time test for serial 1,2,3,4 ** **-------------------------------------------------------------------------------------------------------- *********************************************************************************************************/ #include #include #include #include #include #include #include #include #include #include #include #include #include #define DATA_LEN0xFF/* test data's len*///#define DEBUG1/********************************************************************************************************* ** Function name:openSerial ** Descriptions:open serial port at raw mod ** input paramters:iNumserial port which can be value at: 1, 2, 3, 4 ** output paramters:NONE ** Return value:file descriptor ** Create by:zhuguojun ** Create Data:2008-05-19 **-------------------------------------------------------------------------------------------------------- ** Modified by: ** Modified date: **-------------------------------------------------------------------------------------------------------- *********************************************************************************************************/ static int openSerial(char *cSerialName) { int iFd; struct termios opt; iFd = open(cSerialName, O_RDWR|O_NOCTTY|O_NONBLOCK|O_NDELAY); if(iFd < 0) { perror(cSerialName); return -1; }tcgetattr(iFd, &opt); //cfsetispeed(&opt, B57600); //cfsetospeed(&opt, B57600); cfsetispeed(&opt, B115200); cfsetospeed(&opt, B115200); /* * raw mode */ opt.c_lflag&=~(ECHO|ICANON|IEXTEN|ISIG); opt.c_iflag&=~(BRKINT|ICRNL|INPCK|ISTRIP|IXON); opt.c_oflag&=~(OPOST); opt.c_cflag&=~(CSIZE|PARENB); opt.c_cflag|=CS8; /* * 'DATA_LEN' bytes can be read by serial */ opt.c_cc[VMIN]=DATA_LEN; opt.c_cc[VTIME]=150; if (tcsetattr(iFd,TCSANOW,&opt)<0) { return-1; }return iFd; }//粘连的字符串最后保存在*p指向的地址所在的内存中 static int mystrcat(char *p,char *q) { int ret = -1; char *pp = p; ret = (p != NULL) && (q != NULL); if(ret) {while(*pp != '\0') { pp++; } while(*q != '\0') { *(pp++) = *(q++); } *(pp) = '\0'; }return ret; }//char read_buf[256] = {'\0'}; char read_nBytes[1024]; void Serial_Thread(void *threadarg)//serial_client 线程 { char read_buf[1024]; char tmp[1024]; static int len = 0; int readnum = 0; int fd, i; fd = openSerial("/dev/ttymxc1"); tmp[0] = 'A'; tmp[1] = 'T'; tmp[2] = 'I'; tmp[3] = '\n'; write(fd,tmp,4); while (1) { if((readnum = read(fd,read_nBytes,8))>0) { len += readnum; if(readnum == 8) { read_nBytes[readnum] = '\0'; mystrcat(read_buf,read_nBytes); }if(readnum > 0 && readnum < 8) { read_nBytes[readnum] = '\0'; mystrcat(read_buf,read_nBytes); printf("read_len:%d\n", len); printf("read_buf:%s\n", read_buf); len = 0; bzero(read_buf,sizeof(read_buf)); } } } }int main(void) { int rc,fd; pthread_t Serial_thread; printf("using /dev/ttymxc1 for self-test\n\n"); // 创建sockcet线程一直检测数据的到来或者写入 rc = pthread_create(&Serial_thread, NULL,(void *)Serial_Thread,NULL); if (rc) printf("ERROR; return code from pthread_create() is %d\n", rc); while(1); }

接收超过八的数据