Updated language to match Graham's suggestions

This is a sizable change to freebsd-update that I don't believe is necessary. Closing.

I tested this patch against CURRENT and the update wakes my generic AMD desktop at the specified time using efiwake.

Dragonfly Mail Agent becoming the default mta makes this change moot. :)

This is a very large diff because I essentially split the command line and config parsing code from the actual update functions (fetch, install, update, etc). The reason I split them is to be able to execute the commands shell script with lockf(1) to lock the working directory. I avoided making any changes to the update functions themselves other than cron. I didn't want to lock the working directory during the cron splay time so I pulled just its sleep into the parsing script.

I tested this patch on a Lenovo T480 laptop and a generic AMD desktop running CURRENT. Both reported that they supported EFI wake time.

Yeah, I think supporting EFI wake time could be useful to some folks. I've got a box running current I'll test with if you're able to rebase the patch.

I was unable to test this patch. efi.h patch fails against CURRENT. D28620 abstracted the EFI public interface functions to support Xen VMs.

@imp reviewed my code when I added a feature to top awhile back, let's see if he has time.

Neat feature! Tested and it appears to function correctly. I just noticed a simple grammar error in man page update.

• dst and mask as stack variables
• simpler flag calculation

Honestly, I don't have an opinion on whether the documentation or code should be changed.

• updated from reviewer notes

Thanks again for the reviews. The rib_walk function is indeed much better than a kernel sysctl! Not sure if Linux outputs multipath routes in proc/net/route, I'll take a look at its source.

• support metric

working version utilizing rib_walk

Ideally, I'd like to only malloc only the amount of memory needed for the sysctl results. This works in user sysctl by passing a NULL to oldp but the kernel_sysctl function doesn't appear to work the same way.

Updated source from dchagin comments