#include <stdio.h>

int main()
{
    FILE *txtFile = NULL, *binFile = NULL;
    char *buffer;
    long len;

    // OPEN FILES
    txtFile = fopen("myFile.txt", "r");
    binFile = fopen("binFile", "wb");
    if (binFile == NULL || txtFile == NULL) {
        printf("File cannot be open!\n");
        exit(1);
    }
    // OPEN FILES

    //READ DATA FROM FILE
    fseek(txtFile, 0, SEEK_END);
    len = ftell(txtFile);
    rewind(txtFile);
    buffer = calloc(1, len + 1);

    if ((fread(buffer, sizeof(char), len, txtFile)) != strlen(buffer))
    {
        printf("Errrrr!");
    }
    //READ DATA FROM FILE

    fclose(txtFile);
    printf("%s\n", buffer);

    //WRITE DATA TO BINNARY FILE
    if (fwrite(buffer, sizeof(char), strlen(buffer), binFile) != strlen(buffer)) { //same
        printf("Err!");
    }
    //WRITE DATA TO BINNARY FILE
    fclose(binFile); //close binnary file.

    ////////////////////////////////////////////

    FILE *readBinFile;
    readBinFile = fopen("binFile", "rb");
    char *buff;

    fseek(readBinFile, 0, SEEK_END);
    int binFileLen = ftell(readBinFile);
    rewind(readBinFile);

    buff = calloc(1, binFileLen + 1);
    fread(buff, sizeof(char), strlen(buffer), readBinFile);
    printf("%s\n", buff);
    fclose(readBinFile);

    free(buffer);
    free(buff);
    return 0;
}