[bigtomrodney]

Originally Posted by wje_lf

Two nits, one unimportant, one important.

The unimportant one: By "created", I assume you mean "most recently modified", correct?

The important one: By "millisecond", I hope you mean "second".

On the first one, I meant modified. Absolutely got me there!

On the second one I was about to say that rsync actually works in bundles of 3 milliseconds. Then the penny dropped how silly that sounded and I remembered that I was actually thinking of was the database I use at work.

So I've been busily off looking for a reference to anything close to it, and best I have come up with was a reference to filesystem timestamp resolution in the man page for rsync, and that ext4 has nanonsecond timestamps, to improve on ext3. I've tried getting that for ext3 but so far I've seen everything from seconds to milliseconds so I can't be certain there.

Anyway, if any of that has cast any aspersions on potential fixes I'm sorry

[wje_lf]

Quoth wildside:

I get this:
<snip>

If that's all you get in the output script, then it looks like the script you ran includes only the first of these lines, not the second:

        echo echo cp -p "$f" "$destfile" >> copyscript.sh
        echo cp -p \"$f\" \"$destfile\" >> copyscript.sh

The script should contain both of those lines. Could that be the problem?

[wje_lf]

I'm sorry

Nah. By now this thread is going in a different direction anyway.

What I'm wondering, and maybe if you know C you can help out, or someone else can jump in: If the time of most recent modification is less granular (more precise) than one second, how does a C program pick up on that? The stat() function doesn't go more precise than a second.

[Steve Yau]

I know that my script is NOT determining if the file is newer or not correctly. It thinks that even though it is the same exact mod date that it is newer so it skips it. I belive my error is here:

Code:

if find "$destfile" -newer "$f"

But i dont know what else to add to the switches to make it work.
I thought of maybe using -newerXY

I need it to copy the file as long as it exists with the same date and only skip if the dest file is newer.

Any thoughts?

Yes, the problem is in the IF statement. It would have worked if the exit value($?) for the find -newer return non-zero value when $destfile is newer than $f. Unfortunately this is not the case. The exit value is always zero and that's why the statement in THEN is always executed.
So to make it work, test the output string from find instead of its exit value. On way of doing it is replace the IF statement with :

if [ `find "$destfile" -newer "$f"` ]

-Steve

[ghostdog74]

Originally Posted by wildside

I need to copy files from FolderA into FolderB replacing all files that already exist in FolderB UNLESS the date of the file in FolderB is newer than the date from the same file in FolderA. In the case that file is newer in the destination, I need to skip copy of that file and move on.

the cp command should have a -u switch. It copies when source is newer than destination. Is that what you want.?

[wje_lf]

He wants not "newer", but "newer or equal". That's the sticking point.

[wildside]

Originally Posted by wje_lf

He wants not "newer", but "newer or equal". That's the sticking point.

Yes. Exactly. that is what seems to be hanging most everyone up on this issue. Seems so trivial.

[wje_lf]

Ok, here's whatcha do:

1. Copy all the files which are newer on FolderA. What remains is to copy all the files whose date and time of most recent modification is the same on both FolderA and FolderB.
2. Run this script, which I have not tested:
   

   #!/bin/bash
   (cd /FolderA; find . | xargs stat -c "%y|%n") > astats.txt
   (cd /FolderB; find . | xargs stat -c "%y|%n") > bstats.txt
   sort astats.txt bstats.txt | uniq -d | sed -e 's/^.*|/cp \/FolderA\//' -e 's/$/ \/FolderB/' > copysametime.sh
   

3. Inspect the file copysametime.sh for accuracy. It should contain copy commands for only those files whose time of most recent modification is identical for both folders.
4. Run that sucker, after changing permissions so you can do so.

This work for you?

[wildside]

Ok. gonna give this a shot. Much different approch than before. Hope this works.
Thanks for all the help on this.

[wildside]

What is the switch -c? I get this error when i run it on my macbookpro:

wildside@wildsides-MacBook-Pro / $ ./copytest4
stat: illegal option -- c
usage: stat [-FlLnqrsx] [-f format] [-t timefmt] [file ...]
stat: illegal option -- c
usage: stat [-FlLnqrsx] [-f format] [-t timefmt] [file ...]

i can look for the same option in my man page but i just need to know what the -c is supposed to do.

thanks