CODEWITHSUNDEEP
c
shmulikm
shmulikm

Reputation: 135

how to change uint8_t array to a number

I want to change a uint8_t array type to a int or string type, so i can write it in a text file. for example array:

uint8_t outstr[4]; \\ outstr is 0x00 0x04 0x49 0xba

i tried using this code:

fprintf(ptr_myfile, "%d \n", *outstr);

this code give me only the first number '0' ,but I need the all array. the expected result of the hex number 0x000449ba should be 281018.

Upvotes: 2

Views: 554

Answers (2)

0___________
0___________

Reputation: 67475

two another ways:

typedef union
{
    uint32_t u32;
    uint8_t u8[4];
}u32_t;

int main()
{
    u32_t u32u;
    uint32_t u32;

    /* -----------------------*/

    memcpy(&u32, outstr, sizeof(u32));
    printf("%u", u32);


    /* -----------------------*/

    //you can also use a loop
    u32u.u8[0] = outstr[0];
    u32u.u8[1] = outstr[1];
    u32u.u8[2] = outstr[2];
    u32u.u8[3] = outstr[3];

    printf("%u", u32u.u32);

    return 0;
}

Upvotes: 0

Osiris
Osiris

Reputation: 2813

If your array size is always 4 you could create a uint32_t variable:

uint32_t num = 0;
for(int i=0; i<4; i++)
{
    num <<= 8;
    num |= outstr[i];
}

fprintf(ptr_myfile, "%" PRIu32 "\n", num);

Upvotes: 4

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