File permissions & chmods

[cdxrevvved]

Ok, linux newbie.. Installed mandrake, apache, php, mysql..etc..

In a script, I am trying to do a chmod($curdir, 0777) where $curdir is something like "/var/www/html/web/test"

It fails everytime.. Im just running it locally right now, and it fails if Im logged in as a user or as the root..

$curdir = "/var/www/html";
if(!chmod($curdir, 0777))
   {
       print("chmod failed...");
    }
else
   {
       print("ok");
   }

that should be all there is too it, right? So what am I doing wrong?

Oh and before someone says permissions, I have set permissions on the html directory to give me full read,write & execute... Unless mandrake is screwy in that fashion..

[davetshave]

Uhmm.... Sorry to say the 'P' word but when you said you had configured Mandrake so the permissions were set to you, which user did you actually mean?

Remember Apache runs through it's own user (called apache on my system). It is that user which would have to have the right to chmod. Or else apache would have to be a member of the group allowed to make the alteration. You might want to consider the safety issues involved carefully before choosing the solution which best suits your needs.

If you hadn't specified that it was you who had the permission I would have not mentioned this. Sorry if I interpreted your post incorrectly.

Greetings,

DaveTshave.

[cdxrevvved]

no actually you bring up a good point... Now my question is, if I have a linux server on somehost... I pay for the hosting, this is my webspace.. Ok.. Now.. I upload this bit of script because I want to be able to do chmods, etc...

Now, the owner of those files and folders in my webspace would be me, right? But if I access it through my script, the user would be apache, or whatever server they run...

So i think in theory then, PHP has a chgrp cmmd... sheesh... trying to figure this out is a pain.. lol.. specially when you know next to nothing about linux...

I assumed that If I was logged in as root, even through the webbrowser, I would still have full permissions... apparently not...

Oh well, appreciate the insight... 🙂

[davetshave]

Had exactly the same problem myself once. Didn't really understand why things didn't work properly until I bit the bullet and installed linux on a local machine which I use for development.

Security is a nightmare if you are used to windows. Or maybe windows is a nightmare if you are used to security 😉

[theeper]

If PHP is setup as an apache mod, your scripts will always run as the apache user (nobody or apace usually). If PHP is installed as a CGI, you can log in as root and run the scripts a root. Forget about chmoding if PHP is an apache mod.

[cdxrevvved]

Well, the goal was a file management utility to be uploaded to the server, giving you full access to edit, delete, rename files, etc.. It works wonderfully in windows..

I may have an alternative if I set up an option to use ftp mode instead... I'll have to investigate a little more..

[miahfost]

If you write a script which changes permissions, the script will run as the user who started that script.

So if you create a php script and tell Apache to run it, via the web, then Apache will run the script. Apache has to have the power to change permissions (chmod.) And this is <b>extremely</b> dangerous! So it is not granted by default. It cannot become root, who is the user who can chmod, so it must "sudo." To sudo it must be listed in the sudoers file. (See the sudoers man page for the details on how to write a sudoers file.)

Again, see chroot jails for this type of use.

I know this is complicated, and does not work like Windows. But then, you are not exposed to downtime and hard drive destruction through SQL Slammer, code red, melissa, etc.