On 11/15/11 19:33, Linda A. Walsh wrote: > Why don't we > focus on the specific problem mentioned which was using it in the context of > the "-u" flag, (and with -a/-r and/or a wildcard), where you expect it to > update > contents of 'Dst' with 'Src'.
I'd rather not have a heuristic that says "cp removes the destination when interrupted, if you use the -u flag with -a or -r or a wildcard". That'd be a hard rule to remember, and it's probably not the "best" rule anyway, for somebody's opinion of "best". We need a simple rule that's easy to document and to remember, even if it isn't necessarily the "best" by some other measure. It'd be OK if "cp -a" implies the new --remove-destination=signal (or whatever) option. Then you could just use "cp -a". > cp could check file sizes and see > if the target is smaller and if so.. assume, if the DT's were equal that the > file cp was > interrupted...and finish it... I'm still not convinced by the idea about trusting the time stamp on the destination. Every time 'cp' writes to its destination, it will update the destination's time stamp. Sure, 'cp' can use utime immediately afterwards to alter the time stamp, but there's still a window where the destination's time stamp will be 'now'. In general 'cp' must continue to work in that case -- so why should it bother to reset the destination's time stamp after every write?
