Please mention in the chown documentation when and if always, chown
will only write to the disk if something needs to be changed!
--- Begin Message ---
On Tue 12 Apr 2005, Dan Jacobson wrote:
>
> Instead of
> nohup chown -R proxy:proxy /var/cache/wwwoffle....
> Perhaps only change the files that need it:
>
> cd /var/cache/wwwoffle #makes shorter xargs list
> p=proxy
> find /var/lib/wwwoffle/ . ! \( -user $p -group $p \)|
> xargs --no-run-if-empty chown $p:$p
>
> That way folks' backup schemes wouldn't get fooled into thinking those
> files need to get backed up again due to changes.
If those files are in fact changed by the chown, then it was necessary,
and doing an intermediate find step will only cost more performance.
Demonstration:
[EMAIL PROTECTED]:/tmp$ stat /tmp/wwwoffle.conf.diff
File: `/tmp/wwwoffle.conf.diff'
Size: 265 Blocks: 8 IO Block: 131072 regular file
Device: 302h/770d Inode: 127282 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 1214/ paul) Gid: ( 50/ staff)
Access: 2004-12-08 16:32:03.000000000 +0100
Modify: 2004-12-08 16:31:50.000000000 +0100
Change: 2004-12-08 16:31:58.000000000 +0100
[EMAIL PROTECTED]:/tmp$ date
Wed Apr 13 11:24:58 CEST 2005
[EMAIL PROTECTED]:/tmp$ chown paul:staff wwwoffle.conf.diff
[EMAIL PROTECTED]:/tmp$ stat /tmp/wwwoffle.conf.diff
File: `/tmp/wwwoffle.conf.diff'
Size: 265 Blocks: 8 IO Block: 131072 regular file
Device: 302h/770d Inode: 127282 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 1214/ paul) Gid: ( 50/ staff)
Access: 2004-12-08 16:32:03.000000000 +0100
Modify: 2004-12-08 16:31:50.000000000 +0100
Change: 2004-12-08 16:31:58.000000000 +0100
I don't see that any attribute of the file has changed; if a backup
scheme *does* see a change, then that backup scheme is at fault and your
proposed "fix" won't serve any purpose.
Paul Slootman
--- End Message ---
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