[Samba] prevent smbclient overwriting on put

[Tristan Hill]

Hi,
I'm using smbclient to upload to a share with guest write access;
smbclient //server/share -U guest -c 'put file'
I would like to prevent the put succeeding if the guest user already 
uploaded a file with the same name but can't see a smbclient option for 
this.  Is there a way to set this?

I'm also thinking it should be considered unsafe default behaviour to 
overwrite the file.

Cheers
Tristan