How to let gets() work correctly?

I just refenece VC++ document.
So you right.

I should write a func to handle it, like this.
char *getstring(char *string)
{ char *pointer; INT ch;

pointer = string; while (1) { ch = _getchar_lk(); if (ch == EOF) { return NULL; }

if (ch == 8) { if (pointer > string) { putchar('\b'); putchar(' '); putchar('\b'); pointer--; } } else if (ch == '\r' || ch =='\n' || ch >= ' ') { putchar(ch); if (ch == '\r') putchar('\n'); if (ch == '\n' || ch == '\r') break; *pointer++ = ch; } }

*pointer = 0; return string;
}

I just refenece VC++ document.
So you right.

I should write a func to handle it, like this.
char *getstring(char *string)
{ char *pointer; INT ch;

pointer = string; while (1) { ch = _getchar_lk(); if (ch == EOF) { return NULL; }

if (ch == 8) { if (pointer > string) { putchar('\b'); putchar(' '); putchar('\b'); pointer--; } } else if (ch == '\r' || ch =='\n' || ch >= ' ') { putchar(ch); if (ch == '\r') putchar('\n'); if (ch == '\n' || ch == '\r') break; *pointer++ = ch; } }

*pointer = 0; return string;
}

Any reason why you missed the instruction how to post source code? Notice any difference in readability?

char *getstring(char *string) {
    char *pointer;
    INT ch;

    pointer = string;
    while (1) {
        ch = _getchar_lk();
        if (ch == EOF) {
            return NULL;
        }

        if (ch == 8) {
            if (pointer > string) {
                putchar('\b');
                putchar(' ');
                putchar('\b');
                pointer--;
            }
        } else if (ch == '\r' || ch =='\n' || ch >= ' ') {
            putchar(ch);
            if (ch == '\r') putchar('\n');
            if (ch == '\n' || ch == '\r') break;
            *pointer++ = ch;
        }
    }

    *pointer = 0;
    return string;
}

By the way - what happens if you have already received characters that you have stored in your string when you get an EOF?

Another thing - exactly how large is your string? What happens if someone enters moer characters than what will fit in string?

Remember that VC++ documentation will deal with the specific VC++ implementation; you should not assume that what it says is generally applicable to all implementations - especially embedded cross-compiler implementations!

I don't think the VC++ documentation claims such behaviour either, since such behaviour is not part of the C standard and platform-specific behaviour should only be introduced when the platform so needs.

I can't find anything in my VC++ documentation.

But as I did mention - when the sending side handles the data line-by-line instead of character-by-character, it can process the backspace character so you may see this behaviour in a test program even if it isn't gets()/fgets() that is doing the backspace processing.