You still use IPv4 :(
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( ! ) Warning: fopen(countv4): failed to open stream: Permission denied in /var/www/html/ip4.php on line 19
Call Stack
#	Time	Memory	Function	Location
1	0.0003	232496	{main}( )	.../ip4.php:0
2	0.0003	232728	fopen ( )	.../ip4.php:19

( ! ) Warning: flock() expects parameter 1 to be resource, boolean given in /var/www/html/ip4.php on line 20
Call Stack
#	Time	Memory	Function	Location
1	0.0003	232496	{main}( )	.../ip4.php:0
2	0.0005	233160	flock ( )	.../ip4.php:20

( ! ) Warning: fread() expects parameter 1 to be resource, boolean given in /var/www/html/ip4.php on line 22
Call Stack
#	Time	Memory	Function	Location
1	0.0003	232496	{main}( )	.../ip4.php:0
2	0.0005	233192	fread ( )	.../ip4.php:22

( ! ) Warning: ftruncate() expects parameter 1 to be resource, boolean given in /var/www/html/ip4.php on line 23
Call Stack
#	Time	Memory	Function	Location
1	0.0003	232496	{main}( )	.../ip4.php:0
2	0.0005	233328	ftruncate ( )	.../ip4.php:23

( ! ) Warning: fseek() expects parameter 1 to be resource, boolean given in /var/www/html/ip4.php on line 24
Call Stack
#	Time	Memory	Function	Location
1	0.0003	232496	{main}( )	.../ip4.php:0
2	0.0006	233488	fseek ( )	.../ip4.php:24

( ! ) Warning: fwrite() expects parameter 1 to be resource, boolean given in /var/www/html/ip4.php on line 25
Call Stack
#	Time	Memory	Function	Location
1	0.0003	232496	{main}( )	.../ip4.php:0
2	0.0006	233488	fwrite ( )	.../ip4.php:25

( ! ) Warning: flock() expects parameter 1 to be resource, boolean given in /var/www/html/ip4.php on line 27
Call Stack
#	Time	Memory	Function	Location
1	0.0003	232496	{main}( )	.../ip4.php:0
2	0.0006	233488	flock ( )	.../ip4.php:27

( ! ) Warning: fclose() expects parameter 1 to be resource, boolean given in /var/www/html/ip4.php on line 28
Call Stack
#	Time	Memory	Function	Location
1	0.0003	232496	{main}( )	.../ip4.php:0
2	0.0006	233440	fclose ( )	.../ip4.php:28