On 04/06/2012 01:01 AM, Ángel González wrote: > On 05/04/12 21:51, Daniel A. Nagy wrote: >> Version: 1.13.4 >> Operating System: OpenWrt 10.03.1 >> Kernel: Linux 2.6.32.27 >> Filesystem: vfat >> >> What happens is that wget -N writes a filestamp that is one second >> earlier than the Last-modified HTTP header and therefore when invoked >> again, downloads the same file again even though it should not. So, the >> timestamp it uses for comparison is right, but the one that ends up >> written on the filesystem is wrong. >> >> It's not even consistent, with most files it works okay, but for some, >> it does not work. So far, I did not manage to find any pattern in those >> files that end up mis-timestamped. > vfat has a two-second precision for modified time. If the file was last > modified > in an odd second (if I remember right), the filesystem will store it in > the even > one, thus always showing as modified. Many tools get fooled with that, such > as make.
Thank you! That makes a lot of sense and indeed seems to be the root of my problem. Now, I can (and will) obviously work around it (e.g. by using a different fs), but maybe this would be a nice feature in wget: a switch that turns off least significant bit comparison (that is masks both before comparing) in timestamps when deciding whether or not to download. So, consider this a feature suggestion. I might even implement it myself. Cheers, -- Daniel
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