SSH backup via PHP problem

I am trying to backup all the files on our server using some SSH commands via PHP and I have a script working to some extent.

The problem is that only some of the folders actually 开发者_如何学Gocontain any files but the folder structure seems to be correct though.

This is the script I am using:

<?php
   $output = `cd /
   ls -al
   tar -cf /home/b/a/backup/web/public_html/archive.tar home/*`;

   echo "<pre>$output</pre>";
?>

I cant even view the files via SSH commands, an example of this is the test account. If I use the following command I am unable to view the website files.

<?php
   $output = `cd /home/t/e/test/
   ls -alRh`;

   echo "<pre>$output</pre>";
?>

But if I use the same commands on the a different account I am able to see and download of the website files.

Is this a permission problem or am I missing something in my script?

Thanks

---

ls -l / | grep home

the output will be like this:

lrwxr-xr-x   1 root  wheel        8 Mar 30 14:13 home -> usr/home

In my case, the owner is root, and the root user its primary group is wheel, so now we add www-data user to wheel group so he can list files in there:

usermod -a -G wheel www-data

You can download some files because they located in directory owned by www-data user, and when you can't, www-data has no permission in that.

---

I think it permission problem, try to give apache user(or what you set it) permission to read /home/* directory's. To find the user name that used by apache service run this: For linux:

egrep -iw --color=auto 'user|group' /etc/httpd/conf/httpd.conf

For FreeBSD:

egrep -iw --color=auto '^user|^group' /usr/local/etc/apache22/httpd.conf

---

My guess is that PHP is running in a chroot.

If you just want to execute a backup, consider doing it in a different language. Especially if it is just a sequence of UNIX commands, write a shell script. Perhaps more details on what this script will be used for and who is providing and maintaining your hosting will be useful.