On 10/04/14 15:52, Isaac Dunham wrote: > acpi: never follow symlinks, always recurse in dirs. > > /sys/class contains several directories, each containing symlinks to > devices of a given type. > The symlinks are where we want to end recursion. > This makes for a simpler, cleaner, and more correct check, avoids needless > recursion, and shrinks the text segment by 25 bytes (at least here).
I _totally_ got bit by this doing mdev back on busybox... repeatedly: http://lists.busybox.net/pipermail/busybox/2006-February/052297.html http://lists.busybox.net/pipermail/busybox/2008-July/066210.html I.E. things that were directories can become symlinks, and vice versa. I'm reluctant to trust it. > -- > I noticed that this approach was possible while poking around thinking > about a possible Busybox port, plotting to add -c and -t, and experimenting > with using nftw. > > acpi -c seems to be fairly simple: I have no idea what acpi -c or -t are supposed to _do_, and you don't say here. > recurse through /sys/class/thermal, > read type, max_state, and cur_state, > if max_state and cur_state were unreadable, > printf("Cooling %d: %s no state information available\n", ctr++, type) > else printf("Cooling %d: %s %d of %d\n",ctr++,type,cur_state, max_state) > > It would be rather difficult to do this in the same callback as -ab. Not knowing what -ab do, i think I'll have to re-reply to this message when I have time to dig through the code and see what the existing one does... > The above method does ignore quite a few sensors; > there's no obvious way to get HDD temps besides these commands: > smartctl -A -d ata /dev/sda |grep Temperature > # or (Hitachi-only, but no spin-up) > hdparm -H /dev/sda strace, the breakfast of champions. > Then also Thinkpads have multiple sensors, which are apparently named > (in sysfs) temp*_input > The "official" acpi misses both the Thinkpad sensors and HDD sensors. If you have the testing environment, by all means let's get this right. Query: what are you trying to _do_? Rob _______________________________________________ Toybox mailing list Toybox@lists.landley.net http://lists.landley.net/listinfo.cgi/toybox-landley.net