FTP and access rights

UNIX for Advanced & Expert Users
1

Hello all,
I am currently writing an application that besides other thing ,ftps files from remote machines (running linux and solaris). My problem is this: i am connecting to remote machines as a user other than root and i have found that there is a possibility that i will encounter folders with no 'x' access rights, meaning that ftp from these folders fail. Can I somehow declare a user 'special' and give him root priviliges when ftping? (something similar to sudo with other commands).

Thank you.

2

Do you mean something like /etc/sudoers?

With that file I think it's possible to give users extended privilages just for one kind of operation.

Im not sure, just an idea. Try man sudoers.

3

No, it's not possible. FTP has no way to allow re-authentication, or to start and interact with external programs, neither on the server or client side.

You could try issuing a get with the absolute path of the file, if known, from outside the directory. That way you don't need the execute permission set. Explanation: for directories, the permission bits work a bit differently:

  • Write means the permission to create new directory entries (eg. new files or sub-directories).
  • Read means the permission to list the contents of the directory.
  • eXecute means the permission to change into the directory.

So depending on the implementation used, it might be possible to list the files in a directory and download them without changing into it.

4

Thank you very much pludi, it is very clear now.
In ftp I am using the absolute path (from root directory) but still files that are under a dir with no X permissions are not being ftp'ed.