/* simple CAN application example  *  * open CAN and test the read(2) call * An calling option  decides if the CAN device is opened for * blocking or nonblocking read. */#include <stdio.h>#include <stdlib.h>#include <sys/types.h>#include <sys/stat.h>#include <sys/time.h>#include <sys/ioctl.h>#include <fcntl.h>#include <unistd.h>#include <string.h>#include <can4linux.h>#define STDDEV "can0"#define COMMANDNAME "receive"#define VERSION "1.2"#define RXBUFFERSIZE 100#ifndef TRUE# define TRUE  1# define FALSE 0#endifint sleeptime            = 1000;	/* standard sleep time */int debug                = FALSE;int baud		 = -1;		/* dont change baud rate */int blocking		 = TRUE;	/* open() mode */int buffers		 = RXBUFFERSIZE;/* open() mode */int listenmode		 = FALSE;	/* listen only mode *//* ----------------------------------------------------------------------- */void usage(char *s){static char *usage_text  = "\ Open CAN device and display read messages\n\ Default device is /dev/can0. \n\Options:\n\-d   - debug On\n\       swich on additional debugging\n\-b baudrate (Standard uses value of /proc/sys/Can/baud)\n\-n   - non-blocking mode (default blocking)\n\-B n - buffer size used in non-blocking mode (100)\n\-s sleep sleep in ms between read() calls in non-blocking mode\n\-l     Listen only mode\n\-V   version\n\\n\";    fprintf(stderr, "usage: %s [options] [device]\n", s);    fprintf(stderr, usage_text);}/************************************************************************* set_bitrate - sets the CAN bit rate*** Changing these registers only possible in Reset mode.** RETURN:**/int	set_bitrate(	int fd,			/* device descriptor */	int baud		/* bit rate */	){Config_par_t  cfg;volatile Command_par_t cmd;int ret;    cmd.cmd = CMD_STOP;    ioctl(fd, CAN_IOCTL_COMMAND, &cmd);    cfg.target = CONF_TIMING;     cfg.val1   = baud;    ret = ioctl(fd, CAN_IOCTL_CONFIG, &cfg);    cmd.cmd = CMD_START;    ioctl(fd, CAN_IOCTL_COMMAND, &cmd);    if (ret < 0) {	perror("set_bitrate");	exit(-1);    } else {	ret = 0;    }    return ret;}/************************************************************************* set_lomode - sets the CAN in Listen Only Mode*** Changing these registers only possible in Reset mode.** RETURN:**/int set_lomode(int fd){Config_par_t  cfg;volatile Command_par_t cmd;int ret;    cmd.cmd = CMD_STOP;    ioctl(fd, CAN_IOCTL_COMMAND, &cmd);    cfg.target = CONF_LISTEN_ONLY_MODE;     cfg.val1   = 1;    ret = ioctl(fd, CAN_IOCTL_CONFIG, &cfg);    cmd.cmd = CMD_START;    ioctl(fd, CAN_IOCTL_COMMAND, &cmd);    if (ret < 0) {	perror("set_lomode");	exit(-1);    } else {	ret = 0;    }    return ret;}/************************************************************************* main - ***/int main(int argc,char **argv){int fd;int got;int c;char *pname;extern char *optarg;extern int optind;canmsg_t rx[RXBUFFERSIZE];char device[50];int messages_to_read = 1;    pname = *argv;    /* parse command line */    while ((c = getopt(argc, argv, "B:b:dD:hls:nV")) != EOF) {	switch (c) {	    case 'b':		baud = atoi(optarg);		break;	    case 'B':	        buffers = atoi(optarg);	    case 's':		sleeptime = atoi(optarg);		break;	    case 'd':		debug = TRUE;		break;	    case 'l':		listenmode = TRUE;		break;	    case 'n':		blocking = FALSE;		messages_to_read = RXBUFFERSIZE;		break;		break;	    case 'V':		printf("%s %s\n", argv[0], " V " VERSION ", " __DATE__ );		exit(0);		break;		/* not used, devicename is parameter */ 	    case 'D':		if (		    /* path ist starting with '.' or '/', use it as it is */			optarg[0] == '.'			|| 			optarg[0] == '/'			) {		    sprintf(device, "%s", optarg);	        } else {		    sprintf(device, "/dev/%s", optarg);		}		break;	    case 'h':	    default: usage(pname); exit(0);	}    }    /* look for additional arguments given on the command line */    if ( argc - optind > 0 ) {        /* at least one additional argument, the device name is given */        char *darg = argv[optind];	if (	    /* path ist starting with '.' or '/', use it as it is */		    darg[0] == '.'		    || 		    darg[0] == '/'		    ) {		sprintf(device, "%s", darg);	} else {	sprintf(device, "/dev/%s", darg);	}    } else {	sprintf(device, "/dev/%s", STDDEV);    }    if ( debug == TRUE ) {	printf("%s %s\n", argv[0], " V " VERSION ", " __DATE__ );	printf("(c) 1996-2006 port GmbH\n");	printf(" using canmsg_t with %d bytes\n", sizeof(canmsg_t));	printf(" CAN device %s opened in %sblocking mode\n",		device, blocking ? "" : "non-");    }    sleeptime *= 1000;        if(blocking == TRUE) {	/* fd = open(device, O_RDWR); */	fd = open(device, O_RDONLY);    } else {	fd = open(device, O_RDONLY | O_NONBLOCK);    }    if( fd < 0 ) {	fprintf(stderr,"Error opening CAN device %s\n", device);	perror("open");	exit(1);    }    if (baud > 0) {	if ( debug == TRUE ) {	    printf("change Bit-Rate to %d Kbit/s\n", baud);	}	set_bitrate(fd, baud);    }    if (listenmode == TRUE) {	if ( debug == TRUE ) {	    printf(" Change to Listen Only Mode\n");	}	set_lomode(fd);    }    /* printf("waiting for msg at %s\n", device); */    while(1) {      got=read(fd, &rx, messages_to_read);      if( got > 0) {        int i;        int j;        for(i = 0; i < got; i++) {	    printf("Received with ret=%d: %12lu.%06lu id=%ld/0x%08lx\n",		    got, 		    rx[i].timestamp.tv_sec,		    rx[i].timestamp.tv_usec,		    rx[i].id, rx[i].id);	    printf("\tlen=%d", rx[i].length);	    printf(" flags=0x%02x", rx[i].flags );	    printf(" : %c%c : msg=",	    		(rx[i].flags & MSG_EXT) ? 'e' : 's',	    		(rx[i].flags & MSG_RTR) ? 'R' : 'D');	    if( !(rx[i].flags & MSG_RTR) ) {		for(j = 0; j < rx[i].length; j++) {		    printf(" %02x", rx[i].data[j]);		}	    }	    printf("\n"); fflush(stdout);	}      } else {	printf("Received with ret=%d\n", got);	fflush(stdout);      }      if(blocking == FALSE) {	  /* wait some time before doing the next read() */	  usleep(sleeptime);      }    }    close(fd);    return 0;}