현재 리눅스에서 sys_nerr를 지원을 안해서 생긴문제로 질문을 드립니다.

FILE *
dataconn(name, size, mode)
	char *name;
	off_t size;
	char *mode;
{
	char sizebuf[32];
	FILE *file;
	int retry = 0;
 
	file_size = size;
	byte_count = 0;
	if (size != (off_t) -1)
		(void) sprintf (sizebuf, " (%ld bytes)", size);
	else
		(void) strcpy(sizebuf, "");
	if (pdata >= 0) {
		struct sockaddr_in from;
		int s, fromlen = sizeof(from);
 
		struct timeval timeout;
		fd_set set;
 
		FD_ZERO(&set);
		FD_SET(pdata, &set);
 
		timeout.tv_usec = 0;
		timeout.tv_sec = 120;
 
		if (select(pdata+1, &set, (fd_set *) 0, (fd_set *) 0, &timeout) == 0 ||
		    (s = accept(pdata, (struct sockaddr *) &from, &fromlen)) < 0) {
			reply(425, "Can't open data connection.");
			(void) close(pdata);
			pdata = -1;
			return(NULL);
		}
		(void) close(pdata);
		pdata = s;
		reply(150, "Opening %s mode data connection for %s%s.",
		     type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
		return(fdopen(pdata, mode));
	}
	if (data >= 0) {
		reply(125, "Using existing data connection for %s%s.",
		    name, sizebuf);
		usedefault = 1;
		return (fdopen(data, mode));
	}
	if (usedefault)
		data_dest = his_addr;
	usedefault = 1;
	file = getdatasock(mode);
	if (file == NULL) {
		reply(425, "Can't create data socket (%s,%d): %s.",
		    inet_ntoa(data_source.sin_addr),
		    ntohs(data_source.sin_port),
		    errno < sys_nerr ? sys_errlist[errno] : "unknown error"); //sys_nerr , sys_errlist 사용
		return (NULL);
	}
	data = fileno(file);
	while (connect(data, (struct sockaddr *)&data_dest,
	    sizeof (data_dest)) < 0) {
		if (errno == EADDRINUSE && retry < swaitmax) {
			sleep((unsigned) swaitint);
			retry += swaitint;
			continue;
		}
		perror_reply(425, "Can't build data connection");
		(void) fclose(file);
		data = -1;
		return (NULL);
	}
	reply(150, "Opening %s mode data connection for %s%s.",
	     type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
	return (file);
}

perror_reply(code, string)
	int code;
	char *string;
{
	if (errno < sys_nerr) //sys_nerr 사용
		reply(code, "%s: %s.", string, sys_errlist[errno]); //sys_errlist사용
	else
		reply(code, "%s: unknown error %d.", string, errno);
}