Force input to be positive numbers only with error handling in C

Question

I have a trivial question to ask. My program should take postive integers only. If there is anything illegal, the user should be prompted to input a number again.

Th

Answer 1

Use fgets to read a whole line into a buffer. If you only want to process the first character, you can just ignore the rest. Something along the lines of:

char buf[MAX_LINE_LEN];
if (fgets(buf, MAX_LINE_LEN, stdin))
{
    char a = buf[0];
    /* Do handling... */
}
else
{
    /* error */
}

Coded in browser, may contain traces of error.