char to hex conversion

[alezan]

Hi everyone,

I'm searching for the answer to the following task. I have to write a function that gets a string with decimal numbers, all separated by a ",". My job is to convert these numbers to hex and pass them to a special, given print-function. My problem is, that I'm not allowed to use printf or sprintf or any other function from a library.
Could somebody help me please? Thank!

[quzah]

problem is, that I'm not allowed to use printf or sprintf or any other function from a library.
Could somebody help me please? Thank!

Sounds like homework. What have you tried so far? I don't see your attempt, which means you haven't read the forum guidelines. Go do that and try your post again. In the same thread.


Quzah.

[alezan]

ok, that is what I've done so far. Is there anything I can optimize? One prob is left: I'd like to call int2hex even if there is no , at the end of the input string (e.g. 78, 10); is there a way I can manage this?
Thanks...

//Calculate Int 2 Hex from String

#include <stdio.h>
#include <stdlib.h>

void int2hex(int number){
     char hexdigit[] = "0123456789ABCDEF";
     char hexnum[7];
     char buffer;
     int i = 0;
     while(number){
                   buffer = hexdigit[(number % 16)];
                   number /= 16;
                   hexnum[i++] = buffer;
     }
     
     char result[i];
     int l;
     for(l = i-1; l >=0; l--){
           result[l] = hexnum[l];
           printf("%c", result[l]);
     }
     //here: Print(result);
}

void filter(char *string){
     int decimal = 0;
     while(*string){
                    if(*string == ','){
                         int2hex(decimal);
                         decimal = 0;                                                              
                    }
                    else if(*string == ' '){
                    }
                    else{
                         decimal = decimal*10 + (*string - '0');
                    }  
                    *string++;
     }
}

int main(int argc, char *argv[]){
  char string [8] = {'7','8',',',' ','1','0',','};
  //int2hex(10000);
  filter(string);
  
  system("PAUSE");	
  return 0;
}