Function fgetline

util/makedefs.c:1596–1638

Read one line from input, up to and including the next newline * character. Returns a pointer to the heap-allocated string, or a * null pointer if no characters were read. * 5.0: redone to use nethack's alloc() rather than libc's malloc() * and realloc(). */

 * and realloc().
 */
static char *
fgetline(FILE *fd)
{
    static const int inc = (BUFSZ / 2) + 16; /* fgets() wants signed int */
    unsigned len = (unsigned) inc, newlen; /* alloc() wants unsigned int */
    char *c = (char *) alloc(len), *cprime, *ret;

    *c = '\0';
    for (;;) {
        ret = fgets(c + len - inc, inc, fd);
        if (!ret) {
            /* don't just assume ret==Null indicates an error; last line
               might lack terminating newline; if previous fgets() read it,
               instead of returning we would have expanded the buffer and
               tried for more, then got Null due to end of file having
               already been reached */
            if (feof(fd) && *c && strlen(c) < len) {
                Strcat(c, "\n"); /* append missing newline */
            } else {
                free((genericptr_t) c), c = NULL;
            }
            break; /* either with or without added newline, we're done */
        } else if (strchr(c, '\n')) {
            /* normal case: we have a full line */
            break;
        }
        /* didn't fit in c[0..len-1]; expand buffer and read some more
           [this was much simpler (and possibly slightly more efficient)
           with realloc() but less safe because return values from malloc()
           and realloc() were not being checked for Null, and efficiency is
           a red herring because growing the buffer will be extremely rare] */
        newlen = len + (unsigned) inc;
        cprime = (char *) alloc(newlen);
        (void) memcpy(cprime, c, len);
        free((genericptr_t) c);
        c = cprime;
        *(c + len) = '\0';
        len = newlen;
    }

    filter_nonascii(c);
    return c;
}

static void
filter_nonascii(char *line)