fgetNUL
if (fgetNUL(buf, sizeof (buf), mesgread) == 0)
int fgetNUL(char *, int, FILE *);
while (fgetNUL(buf, sizeof (buf), mesgread) != 0) {
(void) fgetNUL(buf, sizeof (buf), mesgread);
static int fgetNUL(char *obuf, int rmdr, FILE *file);