How to convert double value into an char array after using strtod? in C

Question

For example, converting a character of string that contains:

{x1 5.12 x2 7.68 x3}

to double values have been converted to:

0.0000005.1200000.0000007.6800000.000000

How do I convert these double values such that it creates a character array that should be:

{0.000000,5.120000,0.000000,7.680000,0.000000}

I have been looking everywhere to do this conversion and nothing seems to work. If someone may please provide a code to do this conversion. These are my codes:

void exSplit(char newEx[50]){             //newEx[50] contains {x1 5.12 
                                            x2 7.68 x3}

    char *delim = " ";
    char *token = NULL;
    char valueArray[50];
    char *aux;
    int i;

    for (token = strtok(newEx, delim); token != NULL; token = 
    strtok(NULL, delim))
    {
            char *unconverted;
            double value = strtod(token, &unconverted);

                    printf("%lf\n", value);

    }

}

Answer 1

You can use scanf to scan for a float. If a float is found, you print it to the result string. In no float is found, you print the zeros to the result string.

It could look like:

#include <stdio.h>
#include <string.h>

int main(void) {
    char newEx[] = "{x1 5.12 x2 7.68 x3}";
    char *token;
    char result[100] = "{";
    char temp[100];
    int first = 1;
    float f;

    for (token = strtok(newEx, " "); token != NULL; token = strtok(NULL, " "))
    {
        if (first != 1)
        {
            strcat(result, ",");
        }
        first =0;
        if (sscanf(token, "%f", &f) == 1)
        {
            sprintf(temp, "%f", f);
        }
        else
        {
            sprintf(temp, "0.000000");
        }
        strcat(result, temp);
    }
    strcat(result, "}");
    printf("%s\n", result);

    return 0;
}

Output:

{0.000000,5.120000,0.000000,7.680000,0.000000}

Note: To keep the code example above simple, there is no check for buffer overflow. In real code you should make sure that sprint and strcat wont overflow the destination buffer.