Hex to ascii conversion in c

srinietrx · 03-16-2016, 05:29 AM

I send below string which is in hex format to server.In between there is one abstract module before sending to server
unsigned char pTAG[] = "9F34031E0300";

In server I am getting in output as
"39463334303331453033303039".

My question is What conversion need to done with pTAG I can get "9F34031E0300". I tried converting into ascii but of no use.

I am using C as programming language.

Guttorm · 03-16-2016, 05:48 AM

You can use sscanf to convert it to some type, for example long long. And then printf to print it decimal. Something like this:

Code:

long long i;
sscanf(s,"%llx",&i);
printf("%lld",i);

sundialsvcs · 03-17-2016, 08:07 AM

My handy programmer's calculator (app) tells me that the hex-string you provided translates to decimal 175045739414272.

So, I'm not sure where that number you're seeing on the server side came from, and I'm not going to try to dumpster-dive right now to find out ... ahh, wait a minute. I see it.

In the string you show, each two-character pair appears to correspond to one of the characters in the hex string, with "39" tacked on to the end for good measure. So, the code simply converted an ASCII(?) character string from one representation to another. It did not properly interpret it as hexadecimal.

The scanf()-based solution described in a previous post should take you right where you need to go. The correct answer that you're looking for is the number given in this post.