Get a message ID
#include <sys/can_dcmd.h> #define CAN_DEVCTL_GET_MID __DIOF(_DCMD_MISC, CAN_CMD_CODE + 0, uint32_t)
| Argument | Value |
|---|---|
| filedes | A file descriptor that you obtained by opening the device. This must be for a transmit or receive mailbox (e.g., /dev/can1/rx2). |
| dcmd | CAN_DEVCTL_GET_MID |
| dev_data_ptr | A pointer to a uint32_t |
| n_bytes | sizeof(uint32_t) |
| dev_info_ptr | NULL |
This command gets the message ID for the mailbox associated with the file descriptor.
None.
The message ID. The form depends on whether or not the driver is using extended MIDs:
int ret;
uint32_t val;
if( (fd = open( "/dev/can1/rx2", O_RDWR)) == -1 )
{
printf("open of %s failed \n", devname);
exit(EXIT_FAILURE);
}
if(EOK != (ret = devctl(fd, CAN_DEVCTL_GET_MID, &val, sizeof(val), NULL)))
{
fprintf(stderr, "devctl CAN_DEVCTL_GET_MID: %s\n", strerror(ret));
} else {
printf("GET_MID = 0x%X\n", val);
}