Fix:

ckcmai.c:3160:13: error: implicit declaration of function 'time' is invalid in C99 [-Werror,-Wimplicit-function-declaration]

ckuusx.c:5980:17: error: implicit declaration of function 'tgetent' is invalid in C99 [-Werror,-Wimplicit-function-declaration]

--- ckcmai.c.orig	2011-08-20 23:20:42.000000000 +0200
+++ ckcmai.c	2020-11-07 06:54:10.000000000 +0100
@@ -1,7 +1,7 @@
 #define EDITDATE  "20 Aug 2011"		/* Last edit date dd mmm yyyy */
 #define EDITNDATE "20110820"		/* Keep them in sync */
 /* Sat Aug 20 17:20:17 2011 */
-
+#include <time.h>
 /* ckcmai.c - Main program for C-Kermit plus some miscellaneous functions */

 /*

--- ckuusx.c.orig	2011-06-17 16:11:34.000000000 +0200
+++ ckuusx.c	2020-12-02 09:30:29.000000000 +0100
@@ -28,6 +28,8 @@
 #include "ckcker.h"
 #include "ckuusr.h"
 #include "ckcxla.h"
+#include <curses.h>
+#include <term.h>

 #ifndef NOHTERMCAP
 #ifdef NOTERMCAP

--- ckupty.c.orig	2011-06-13 17:34:13.000000000 +0200
+++ ckupty.c	2020-12-02 09:17:03.000000000 +0100
@@ -56,6 +56,7 @@

 #include "ckcsym.h"
 #include "ckcdeb.h"			/* To pick up NETPTY definition */
+#include <util.h>

 #ifndef NETPTY				/* Selector for PTY support */

--- ckutio.c.orig	2011-08-20 23:22:35.000000000 +0200
+++ ckutio.c	2020-12-02 09:16:34.000000000 +0100
@@ -41,6 +41,7 @@

 #include "ckcsym.h"			/* This must go first   */
 #include "ckcdeb.h"			/* This must go second  */
+#include <util.h>

 #ifdef OSF13
 #ifdef CK_ANSIC