It's been a while since this first posted so you might not get this, but have you looked at Forklift by Binary Nights?
It does what you're talking about and much more. It's worth checking out, I think.
Oh, and there is also Bresink's SyncChecker. I have not tried it myself, but I own other Bresink software and it is very good software.
Yes there are actually several.
I will lay them out here:
Automator Workflows, LLC (This site has many tuturials and is very helpful, also the owner of this company is very helpful with any questions you have. He has also made a lot of workflow actions that are very useful)
Of course there is. Mac OS is Unix and therefore there are Unix commands that wil do this. For those of use who grew up on Unix in the 1980s and 90s using SGIs and Suns, Unix would be the first place to consider.
One command that comes to mind is "diff". Open an X Terminal and do "man diff". It will give you a manual listing for this command.
The syntax to use is "diff -rq <directory 1> <directory 2>.
-r for recursively list all subdirectories
-q for brief mode
Remember that directory names and file names are all case-sensitive, unlike Windows.
<directoy 1> and <directory 2> stand for the path to your two folders. The paths must either be explicit (i.e. starting with "/" and going all the way down") or relative to the directory from which you are submtting the command.
Of course there is. Mac OS is Unix and therefore there are Unix commands that wil do this....
My request was for a visual way to do this, with easy selection (by mousing, etc.) of what files or folders should be copied in which direction, buttons or menu items to perform the actions, etc. In this day and age, it's ridiculous to have to resort to *nix command-line shenanigans for such things.
What about GoodSync? See http://www.goodsync.com/mac/how-it-works/file-synchronization
I believe this is is what you need. I use it on both MAC and Windows.
I ran the trial version of GoodSync and find the results of a folder comparison rather opaque, i.e., hard to interpret.
Moreover, I don't trust the developers: I also installed the GoodSync command-line tools and without any warning whatsoever that created a .bash-profile file. And that had the effect of clobbering everything in my .profile (since when Terminal is opened, .bash-profile is read first and then .profile is skipped entirely). Oh, and yes, despite what I said to a another's suggestion of using built-in Unix tools for comparisons, I do use the command-line for many things where no GUI app is available.
I'm glad to see this thread is still active. In the 4 or 5 years since I began switching to macs I've looked for an osx app that does precisely what you asked for, murrayE ;-) I bought pathfinder, transmit, chronosync--they're all fine for their particular uses, but don't exactly do the things you ask for. I tried forklift, but that didn't fill the bill for me.
I was pleased to learn about kdiff3 in this thread. I downloaded it & will give it a try!
Beyond compare looks like a great program (haven't used it in windows though) and I have followed its developers' efforts to get that ported to osx--I'd surely buy it if that happens.
But for hundreds of Gb of photo libraries and mathematical & statistical modeling and analysis work, I need something which I can absolutely, positively trust and that is transparent & easy to use. Just haven't found that on osx yet.
For now I continue to rely on win apps I've used over 15 years. I keep Total Commander (TC)
(ghisler dot com) running in a win7 parallels vm (actually in a coherence window on my osx desktop). I use the internal file & directory compare/sync tools in TC some of the time. Most of the time I use Compare It! and Sync It! from (grigsoft dot com) for file & directory compare/sync. I put the source & destination directories in Total Commander's 2 file manager panes and then have an icon on TC's "button bar" which launches Sync It! as a subprogram. TC's file & directory compare/sync tools are great, but the ones from Grigsoft offer much richer customization options for the file or directory operations (and they have a pleasing and functional UIs). Plus you can save custom setups with different parameter & option sets for different types of jobs you might want to do with the grigsoft tools.
Parallels 8 runs win apps rock solidly for me. Programs and subprograms just open up right on the desktop (in coherence mode).
I haven't figured out why similar tools didn't seem to develop for OSX. There are several fine OSX sync programs, but I have had trouble getting them to do what I want: Chronosync is fine for backing up a drive, but I've found it for ,say, syncing 1 main folder with hundreds of populated subfolders from a source to a target drive--I can do it, but I've got to be crazy careful or I'll end up duplicating the folders & files inside of one of the target folders or some similar error--instead of just updating the target with changes in the source. I like Transmit, but while I can get it to do precisely the type of directory sync from my local source drive to e.g. a remote web server, I cannot get it to do the same thing onto, say, my local file server.
I'm happy to use unix command line apps and have used them a lot over the years. But I don't find some script I've written with diff or other utilities as transparent or trustworthy as a GUI which gives me that visual confirmation I like. Wouldn't have rambled on so long except that just now I'm almost done with a Sync It! run checking over 91,000 files and hundreds of Gb from some photo libraries and I can see each file's status before and after. And for some reason a new USB3 destination drive is dismounting on its own which could be catastrophic. Yet Sync It! handles this pretty gracefully, notifying me of files that didn't get copied and letting me rescan and resume.
I would prefer a native OSX app as doing OSX file management with a win7 vm is a bit scary for a relative osx newbie. But fortunately apps I use like lightroom & photoshop and even mathematical modeling stuff like R and Rstudio, etc. don't seem to mind. The differing permission systems and hidden files like .DS_Store are a bit of a worry, but I haven't clobbered anything in the past 5 years. (Early on, I did have to learn how to reset file permissions with terminal commands ;-) but I don't have to futz with such things much recently.)