Fix implicit declaration of functions.
--- configure.orig	2004-05-06 15:41:10.000000000 -0500
+++ configure	2021-03-05 12:01:28.000000000 -0600
@@ -1395,6 +1395,7 @@
 #line 1396 "configure"
 #include "confdefs.h"
 #include <ctype.h>
+#include <stdlib.h>
 #define ISLOWER(c) ('a' <= (c) && (c) <= 'z')
 #define TOUPPER(c) (ISLOWER(c) ? 'A' + ((c) - 'a') : (c))
 #define XOR(e, f) (((e) && !(f)) || (!(e) && (f)))
@@ -1921,6 +1922,8 @@
   cat > conftest.$ac_ext <<EOF
 #line 1923 "configure"
 #include "confdefs.h"
+#include <stdlib.h>
+#include <string.h>
 
 main()
 {
--- src/chgrep.c.orig	2004-06-15 15:07:22.000000000 -0500
+++ src/chgrep.c	2021-03-05 12:04:48.000000000 -0600
@@ -20,6 +20,7 @@
  */
 
 #include	<stdio.h>
+#include	<stdlib.h>
 #include	<sys/stat.h>
 #include	<sys/types.h>
 #include	<utime.h>
@@ -35,6 +36,7 @@
 #include	<limits.h>
 
 #include	"error.h"
+#include	"ftw.h"
 #include	"wrappers.h"
 #include	"functions.h"
 
--- src/error.c.orig	2004-05-29 16:25:07.000000000 -0500
+++ src/error.c	2021-03-05 12:01:28.000000000 -0600
@@ -19,6 +19,8 @@
 
 #include	<stdio.h>
 #include	<stdarg.h>
+#include	<stdlib.h>
+#include	<string.h>
 #include	<syslog.h>
 #include	<errno.h>
 
--- src/functions.c.orig	2004-06-15 15:11:04.000000000 -0500
+++ src/functions.c	2021-03-05 12:03:27.000000000 -0600
@@ -19,6 +19,7 @@
 
 #include	<stdio.h>
 #include	<unistd.h>
+#include	<stdlib.h>
 #include	<string.h>
 #include	<sys/types.h>
 #include	<sys/stat.h>
@@ -28,7 +29,9 @@
 #include	<regex.h>
 #include	<limits.h>
 #include	<dirent.h>
+#include	"error.h"
 #include	"ftw.h"
+#include	"wrappers.h"
 
 #define		MAXLINE	4096
 #define		PERM	0666
--- src/wrappers.c.orig	2004-06-15 14:50:33.000000000 -0500
+++ src/wrappers.c	2021-03-05 12:01:28.000000000 -0600
@@ -19,6 +19,7 @@
 
 #include        <stdio.h>
 #include        <unistd.h>
+#include        <stdlib.h>
 #include        <fcntl.h>
 #include        <sys/types.h>
 #include        <sys/stat.h>
--- src/wrappers.h.orig	2004-06-15 14:52:07.000000000 -0500
+++ src/wrappers.h	2021-03-05 12:05:45.000000000 -0600
@@ -6,7 +6,7 @@
 
 void Unlink(const char *pathname);
 
-ssize_t rite(int fd, void *ptr, size_t nbytes);
+ssize_t Write(int fd, void *ptr, size_t nbytes);
 
 int Open(const char *pathname, int oflag, mode_t mode);
 
@@ -27,3 +27,6 @@
 Sigfunc *Signal(int signo, Sigfunc *func);
 
 void *Malloc(size_t size);
+
+void *Realloc(void *ptr, size_t size);
+