fgets reading previous line before input

Question

when I enter an input, the question repeats before i can enter a string.

printf("Enter %d coefficients starting from the 0th degree.\nSeparate them by commas: ", degree+1);
fgets(coeffs_string, MAX, stdin);
for(i=0;i<strlen(coeffs_string);i++){
    if(coeffs_string[i]==','){
        commas++;
        continue;
    }
    else if(isdigit(coeffs_string[i]) || coeffs_string[i]==' ')
        continue;
    else{
        printf("\007Error! A character was found during the input!\n");
                coeffs_string[0]='\0';
        commas=0;
        break;
    }
}

also, it prints the error handler even when i enter the proper input. I tried using scanf but it just stops. is there a way for fgets or scanf to not quickly read the input? *edit:sorry:i forgot some parts of my code

Answer 1

1. Try putting a fflush(stdout); between your printf() and fgets() statements. Alternatively obtain your input on a separate line from your output.
2. The string returned by fgets() will include the line terminator character/s that the user generated by pushing the enter key. You are not explicitly handling these characters so the error message will always be displayed.