C - 重复提示直到有效的用户输入

Question

如何重复此循环，直到用户输入 -2、-1、0 或正数？

int main(int argc, char argv[]) {
    char n[3];
    char line[LINESIZE];
    fgets(line, sizeof(line), stdin);
    sscanf(line, "%s", n);
    do {
        if (n == 0) {
            printf("DISPLAYING ALL RECORDS.\n");
        append();
        } else if (n > 0) {
            printf("MODIFYING RECORD %s", n);
        } else if (n < 0) {
            printf("APPENDING RECORD %s", n);
        }  else if (n == -2) {
            printf("QUITTING.");
        } else {
            return 1;
        }
    } while (1);

return 0;
}

Answer 1

使用 do/while 循环:

do
{
   // code to be looped (ask the input value)
} while (n < -2)

// here you can check the values as in your code