How can I do "chmod 704" to a folder which I want it to allow others to access and download the entire folder including its sub-folders and files?
From the looks of it, you have the permissions the wrong order. When referencing permission masks with three digits, the order is
In other words, a
704 mask means owner gets it all (as it should be, in most cases), group members don't get anything (which I find a bit odd), and everyone else gets read only.
If you want everyone to be able to read (and hence copy) a folder of yours, including any subfolders, the folder in question should have
755, as well as any subfolders. Files should normally be
644, except from executable ones which should be
A lazy way of achieving what you want is
chmod -R 755 /some/folder/that/you/want/to/share. This will apply a
755 to that folder, and all files and subfolders within. It has the downside of making all files executable (including the ones that shouldn't be), but in most cases this is OK and only a little bit cringeworthy.