Currently I have a basic Ubuntu server running a website. The website is for a few students learning HTML/PHP and each student has their own account with a symbolic link to the shared website folder. Since the students are working on the website together, each user needs to be able to modify all the files (index.html for example). So I created a Webdev group containing all of the students with the default umask of 0002 set in their .bashrc (This allows newly created files to be 774). The shared folder is owned by the group Webdev with a chmod g+s so that new files/folders also belong to the group Webdev.

The problem is that the students are using an IDE (Coda 2) and when they create a new file or folder using the IDE the file has the permissions of 644 on the server (not group writable). However when I make a new file through connecting with Cyberduck (SFTP client) the file permissions are 664 (as they should be). So I don't understand why Coda would be any different.

However, after some trial and error I believe that Coda is first creating the file on local disk and then uploading that file to the server. On a mac by default a newly created file is 644. When the client uploads a file that's already 644 it stays 644 on the server side (umask is kind of useless in this situation). I've also tried creating ACL permissions for that folder but an uploaded file from my mac via SCP doesn't get the default ACL permissions.

In Coda there is an option to change file permissions on a transfer. However this option seems to apply a chmod to all files being uploaded or saved. When one of students is modifying a file created by someone else when they try to upload the file or save it Coda tries to also do a chmod but fails because that user isn't the owner of the file.

My current solution is using bindfs... I mount the shared web folder and bindfs sets permissions and group ownership of newly created files. However, bindfs seems to be a bit slow and I'm sure there is a better solution.

Even if the students ditched Coda 2 and used Mac vim with scp the newly created files on the server would behave the same (644) which is default on the mac.

Other options...

1) Either I teach the students to use (ssh/chmod) with their IDE to change their own file permissions when uploading.

2) I make all the students' Macs have the default umask of 0002 which would upload files with the right permissions.

3) Write a corn script to fix the file permissions every 5 to 15 minutes... (This option I think is the worst if students are working together at the same time).

Is there any way that I could make all files that are uploaded via SCP have the default file permissions of 664 even though the uploaded file has a lower permission? (After hours of searching I don't think this is possible) I guess a corn script is my best option for novice users. How do web developers work together on larger sites?

similar to this: http://serverfault.com/questions/283492/how-to-specify-file-permission-when-putting-a-file-using-openssh-sftp-command

Also similar: http://serverfault.com/questions/395418/managing-linux-directory-permissions-sftp