chmod a bash file.

I am trying to chmod a bash file, and I keep on getting an "operation not permitted" message. Basically, I "chmod 700". I can neither sudo, or su, but I have succesfully done this before, so I wonder what is wrong.

I have also tried "chmod +x", to no avail.

Solved! Once I copied out of the Dropbox folder, I could change permissions.

That's a little strange. Files in Dropbox may be owned by the dropbox user, but they should have group registered users, which everyone belongs to, and read+write permissions for group...

So maybe you can't do chmod +x, but you can do chmod g+x??

Nope. Only the owner of a file may use chmod to modify its permissions. So say the elders of Unix.

What you could probably do is add the execute permissions from your own pc - dropbox will hopefully sync up permissions onto PythonAnywhere...

The elders of Unix are rarely all that wrong... Though they're typically not entirely right, either.

Does Dropbox even support Unix-style permissions? I'd assumed it synchronised content and then it was simply up to the local client to set some appropriate permissions. I'm not really sure what else they could do when they're hoping to be a cross-platform interface, since it's not typically possible to translate, say, Windows permissions into Linux ones. Things like ACLs also make things even more complicated, so I can't really blame them if they've decided to ignore the lot and just sync content.

I tried all the chmod commands I knew, and even got a couple of guys in the office to help. It was weird because I was able to run chmod a couple of days earlier. Personally, I don't mind having to move my application folder somewhere else. I think that may even be more secure than leaving it in the Dropbox folder.

Personally I'm inclined to regard Dropbox as a backup and transfer mechanism, I wouldn't suggest anybody run important code from it (having said that I do run code from it sometimes, but only for toys that doesn't matter if it breaks). That way you've insulated your running website from any issues caused by Dropbox on other systems.