How to read a hex data from a text file in C

Question

I am trying to read a text file with CAN data, the format the file is something like this :

XL_CAN_EV_TAG_RX_OK ch:0 t=51165282304 id:98FF5C80 dlc:7 000000040000E0 XL_CAN_EV_TAG_RX_OK ch:0 t=51172728832 id:98FF1480 dlc:7 FFFFFFAD7C1CFF XL_CAN_EV_TAG_RX_OK ch:0 t=51173007360 id:98FF1080 dlc:7 FFFFE30C0E01FF XL_CAN_EV_TAG_RX_OK ch:0 t=51173285888 id:98FF1180 dlc:7 FFFF9706FEFFFB XL_CAN_EV_TAG_RX_OK ch:0 t=51173564416 id:98FF1280 dlc:7 FFFF9706FEFFFB

I have to read the CANid and the the CANDATA as seen above, I managed to read the CANID using the :

unsigned int hex = 0; 
fscanf(fr, "%X", &hex); 
printf(" %X ", hex);

I use the c = fgetc(fr); till the c reads the second ":" and hex reads the canid fine.

But, when I have to read the data using the same code "fscaf", it only reads the last 7 data for example ,I get results like this :

40000e0 D7C1CFF C0E01FF 6FEFFFB 6FEFFFB

This is the problem. The alternative i found is to read it as char.

If i use the getc to read, I get the data in char format, I am not sure how to convert that to a hex and also it reads each letter separately and I have to combine them and then convert it into an int type (hex) specifically and send it to a array, something like this:

data[0]=FF; data[1]=FF; data[2]=FF; data[3]=AD; data[4]=7C; data[5]=1C; data[6]=FF;

I have been stuck here since two days, googled everything and tried everything, nothing seems to work, can you please help me with this. Thank you.

Answer 1

You're reading an unsigned int and storing into an unsigned int . unsigned int is 32 bits, your hex values are 7 bytes or 56 bits long. You need a 64 bits container for those. You'll want to use unsigned long long int and read/write them with %llX .