I am fairly new to C. I would like to convert a String representation of a HEX number to a actual Hex number ?
#include <stdio.h>
int main()
{
char buf[8] = "410C0000";
printf("%s\n",buf);
return 0;
}
I would like to break up the string and convert it into 4 inividual Hex numbers. Which i can process further for calculations :
0x41 0x0C 0x00 0x00
You can use sscanf, which is a variant of scanf that reads from a string rather than from a stdin or a file. Format specifier %X specifies to treat the input as a hexadecimal number, %02X additionally says to read exactly two digits, and %02hhX additionally defines to store the result into a single byte (i.e. an unsigned char, instead of a probably 64 bit integral value).
The code could look as follows:
int main()
{
char buf[8] = "410C0000";
unsigned char h0=0, h1=0, h2=0, h3=0;
sscanf(buf+6, "%02hhX", &h0);
sscanf(buf+4, "%02hhX", &h1);
sscanf(buf+2, "%02hhX", &h2);
sscanf(buf+0, "%02hhX", &h3);
printf("0x%02X 0x%02X 0x%02X 0x%02X\n",h3, h2, h1, h0);
return 0;
}
Output:
0x41 0x0C 0x00 0x00
BTW: buf - as being of size 8 - will not contain a string terminating '\0', so you will not be able to use it in printf. Write char buf[9] if you want to use buf as a string as well, e.g. when writing printf("%s\n",buf).
buf- as being of size 8 - will not contain a string terminating'\0'. Writechar buf[9]if you want to usebufas a string as well, e.g. when writingprintf("%s\n",buf)