Set the ACL for an object

You can set the ACL when you upload the file:

% aws put --public JohnGShaw/Codes/FastAstro/FastAstro-0.67.tgz FastAstro-0.67.tgz

(Note that --public and --set-acl=public-read are equivalent.)

If you want to manipulate the ACL for a file that is already uploaded, it's more difficult:

% aws get JohnGShaw/Codes/FastAstro/FastAstro-0.67.tgz FastAstro-0.67.tgz?acl acl.xml

(edit acl.xml)

% aws put JohnGShaw/Codes/FastAstro/FastAstro-0.67.tgz FastAstro-0.67.tgz?acl acl.xml

You have to download the ACL XML, modify it, and then set it again.