group permissions questions

[capitano]

I have a "webuser" through which web visitors can upload image files to a directory on the web server.

Unfortunately, when the images get uploaded, they don't get put down with public read permissions.

I tried making my ColdFusion web script execute a "chmod 775" on the images folder, but since the ColdFusion server is running as "webuser" and this folder is owned by "somebodyelse", then I don't have the right permissions to do chmod. Fortunately, both the folder owner and the "webuser" are in the same group however. So I think I must be close to getting this working.

Any suggestions?
Thanks so much.

Bryan

 

[capitano]

Okay, that was a little scattered because I was frusterated. Let me rephrase:

I have two users, call them "bob" and "sally".
I have a common group to which they both belong, called "friends".

In /home/sally there is a directory called "shared" with following permissions:

drwxrwxr-x sally friends 4096 Jan 22 12:08 shared

I want bob to be able to go into /home/sally/shared and create new files. Okay, no problem. Bob can do that because this "shared" directory is open to "friends" group.

My question is this: I want bob to be able to chmod 775 on everything in /home/sally/shared. But I'm getting permission problems.

How can I get bob permissions to do chmod in such a shared folder?

Thanks for any help.

 

[RhythmAce]

You might try setting the gid bit for that directory so all files in it will inherit the group. To do this you would chmod the directory to 2775.

 

[hvn]

You could also set the umask for the users so that any files they copy/create gets a specific set of permissions.

adding something like: umask 002 to each users' .bashrc file should have the desired effect.

umask works on the same basis as chmod, only it dictates the permissions when a file gets created, and where 777 with chmod would give full permission, a umask of 000 will do the same.

-Hannes