One silly chmod question

[m.roth at 5-cent.us]

>>> I have a problem changing permissions to some files using chmod and now
>>> I have a doubt about the owner and group of a file,
>>> I´ll try to explain.
>>> I have 2 users, user1 and user2, both belongs to group1.
>>> I have a file with this permissions:
>>> -rwxrwxrwx 1 user1 group1 file.txt
>>> with user2 I can read, write this file. but If I try to change the
> permissions with this:
>>> chmod 770 file.txt I get the error:
>>> operation not permitted,
>>> so my doubt is, only the owner can change the permissions to a file?
>>
>> Think about the *meaning* of what you tried to do: you, as a member of
> the group, but not as the owner, are trying to make it so that the owner
> cannot even look at the file, not execute, not write, not even read.
> Does that make sense?
>
> That would be incorrect...he, as a member of the group, but not the owner,
<snip>
Sorry, you're right. My mind's on too many other things....

         mark