[FFmpeg-devel] [PATCH] web: Copy FFmpeg Logo by Makefile instead of cronjob

[Reimar Döffinger]

On 16 Apr 2012, at 23:43, Thilo Borgmann <thilo.borgmann at googlemail.com> wrote:
> Am 16.04.12 21:51, schrieb Reimar Döffinger:
>> On 16 Apr 2012, at 17:36, Thilo Borgmann <thilo.borgmann at googlemail.com>
>> wrote:
>>> Am 14.04.12 18:05, schrieb Reimar Döffinger:
>>>> On Sat, Apr 14, 2012 at 11:46:03AM +0200, Michael Niedermayer wrote:
>>>>> On Wed, Apr 11, 2012 at 12:50:34PM +0200, Thilo Borgmann wrote:
>>>>>>> this will update teh file even if it matches, this breaks caching
>>>>>>> of the logo
>>>>>> 
>>>>>> Updated Patch attached.
>>>>> 
>>>>> from a quick look, its ok maybe reimar can double check ?
>>>> 
>>>> I don't see any real issues with it. Though if you're pedantic there's a
>>>> questions whether "test -r" is the best condition, copying over the file
>>>> to my knowledge won't fix any permissions which is why I went with -f
>>>> originally. I don't think it really matters, when it makes a different
>>>> things are already seriously broken anyway and will need manual
>>>> intervention.
>>> 
>>> I don't really get it.
>>> 
>>> "test -r" or "test -f" - what does that have to do with fixing
>>> permissions?
>> 
>> What is the point of overwriting the file when  the problem is that the file
>> exists but is not readable, when that will be the case afterward still? 
> 
>> That's why I chose -f since it avoids pointlessly copying, but as said I
>> think it doesn't matter really.
> 
> I might misunderstand test, but -f would pointlessly copy if the file is not
> readable. -r would at least not do that but could still fail if the file is not
> writable. So if we check the file, we should have to check r&w permissions.

test -f will fail (and thus cause the copy) when the file is not a regular file (so -e might be better).
test -r will fail when the file is not readable, including when it exists but does not have read permissions.

> What do you think about "cp -f" to retain permissions of the previous/initial
> file? Useful in my eyes if the git repo creates files with different permission
> than we want for the logo file.

I don't know where you got your understanding of the -f option from, but my manpage certainly does not match it.
If the file is writeable -f or not does not make a difference, permissions remain unchanged.
Only if write permissions are missing does the behaviour differ: without -f it will fail, with it will delete the file and potentially recreate it with new permissions (I presume with the default permissions based on umask).