我正在观看此视频https://www.youtube.com/watch?v=gC8sLGB8SSM&index=77&list=PL442FA2C127377F07。我正在使用软呢帽。我可以使用以下代码读取文件：
$fileHandle = fopen('test.txt', 'r') or die('Unable to open test.txt');
echo fread($fileHandle, filesize('test.txt'));
但是当我将'r'更改为'w'时，它死了并显示'Unable to open test.txt'。
要检查我是否有权读写文件，我在终端ls -l /var/www/html上键入了此命令。它显示：
total 8
-rwxr-xr-x. 1 Hemil apache 131 Jul 6 11:09 index.php
-rw-rw-r--. 1 Hemil Hemil 12 Jul 6 11:09 test.txt
我注意到apache没有读取和写入文件的权限，我这样做是：sudo chown Hemil:apache /var/www/html。但是当我检查权限时，它再次显示与上面相同的内容。
编辑：我忘了补充说明我不在服务器上。我在本地主机上。
编辑：根据@ Nic3500的建议，我添加以下内容：
ls -al /var：
total 108
drwxr-xr-x. 23 root root 4096 Apr 25 12:09 .
dr-xr-xr-x. 18 root root 4096 Jul 7 08:17 ..
drwxr-xr-x. 2 root root 4096 Apr 25 12:06 account
drwxr-xr-x. 2 root root 4096 Feb 7 15:11 adm
drwxr-xr-x. 17 root root 4096 Jul 5 10:21 cache
drwxr-xr-x. 2 root root 4096 May 31 10:46 crash
drwxr-xr-x. 3 root root 4096 Apr 25 12:06 db
drwxr-xr-x. 3 root root 4096 Apr 25 12:06 empty
drwxr-xr-x. 2 root root 4096 Feb 7 15:11 ftp
drwxr-xr-x. 2 root root 4096 Feb 7 15:11 games
drwxr-xr-x. 2 root root 4096 Feb 7 15:11 gopher
drwxr-xr-x. 3 root root 4096 Jun 15 03:23 kerberos
drwxr-xr-x. 59 root root 4096 Jul 5 11:55 lib
drwxr-xr-x. 2 root root 4096 Feb 7 15:11 local
lrwxrwxrwx. 1 root root 11 Apr 25 12:03 lock -> ../run/lock
drwxr-xr-x. 18 root root 4096 Jul 5 11:52 log
drwx------. 2 root root 16384 Jul 4 22:54 lost+found
lrwxrwxrwx. 1 root root 10 Feb 7 15:11 mail -> spool/mail
drwxr-xr-x. 2 root root 4096 Feb 7 15:11 nis
drwxr-xr-x. 2 root root 4096 Feb 7 15:11 opt
drwxr-xr-x. 2 root root 4096 Feb 7 15:11 preserve
lrwxrwxrwx. 1 root root 6 Apr 25 12:03 run -> ../run
drwxr-xr-x. 11 root root 4096 Apr 25 12:06 spool
drwxrwxrwt. 16 root root 4096 Jul 7 18:26 tmp
-rw-rw-r--. 1 root root 63 Apr 25 12:09 .updated
drwxr-xr-x. 4 root root 4096 May 1 14:24 www
drwxr-xr-x. 2 root root 4096 Feb 7 15:11 yp
ls -al /var/www
drwxr-xr-x. 4 root root 4096 May 1 14:24 .
drwxr-xr-x. 23 root root 4096 Apr 25 12:09 ..
drwxr-xr-x. 2 root root 4096 May 1 14:24 cgi-bin
drwxr-xr-x. 2 Hemil apache 4096 Jul 6 16:17 html
ls -al /var/www/html
drwxr-xr-x. 2 Hemil apache 4096 Jul 6 16:17 .
drwxr-xr-x. 4 root root 4096 May 1 14:24 ..
-rwxr-xr-x. 1 Hemil apache 102 Jul 7 16:55 index.php
-rw-rw-rw-. 1 Hemil apache 12 Jul 6 11:09 test.txt