I have some strings that come in over a REST interface that represent some network coordinates. The string looks something like:
02:00:00:00:00:07
Bits 5 - 0 represent tier 1
bits 13 - 6 represent tier 2
bits 19 - 14 represent tier 3.
How would I parse these out in C?
I've tried looking online, but I found it quite confusing.
I don't understand your string format, but if you have an unsigned integer and you want those bits as separate values:
Code:#include <stdio.h> int main() { unsigned n = 0xabcde; // 101010 11110011 011110 // 19-14 13-6 5-0 unsigned a = (n >> 14) & 0x3f; unsigned b = (n >> 6) & 0xff; unsigned c = n & 0x3f; printf("%02x (%3u)\n", a, a); // 2a ( 42) printf("%02x (%3u)\n", b, b); // f3 ( 243) printf("%02x (%3u)\n", c, c); // 1e ( 30) return 0; }
A little inaccuracy saves tons of explanation. - H.H. Munro
Assuming this "string" is a MAC address (6 bytes):
Now you can use u.dw as john.c showd above.Code:union { unsigned int dw; unsigned char b[8]; } u = { 0 }; // str points to string... if ( sscanf( str, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx", &u.b[5], &u.b[4], &u.b[3], &u.b[2], &u.b[1], &u.b[0] ) != 6 ) { ... error ... } ...
Yes, that's exactly what it is, a MAC address. Thanks!Originally Posted by flp1969
