Script or commands to sync two folders

[PVR]

Hi !

We have two folders named dir1 and dir2.

we have files in these two folders.

We have some files in these two folders with same name but different time stamps(It can be same time stamp also). I have to sync between the two directories based on the time stamp of files. ie..recently modified file should overwrite the older one in the other directory.

can you suggest me a solution to this ? I think rsync will work. But again rsync won't do the reverse updation.

Thanks
PVR

[Chris Wilshaw]

Do you need to have 2 separate copies of the files, or is this being done to get around some issue within an application?

[TwoProc]

Two passes of rsync should do the trick - one to rsync from /dira to /dirb, and then a second pass from /dirb to /dira. Just to make sure I got it right, I'd probably repeat the whole process once more and observe what it's doing. If it repeatedly(day after day) doesn't need a second pass, you could cut it out.

I realize that rsync is meant for remote systems, but I believe that it can handle the same system as an argument twice equally well.

You can find rsync at:

http://hpux.cs.utah.edu/hppd/cgi-bin/search?package=on&description=on&term=rsync&Search=Search

[Howard Marshall]

I don't know if this will work for you but it if it does it will make life a little more simple.

Make a third directory, use find and cpio to copy files from dir1 into dir3

Then use find and cpio to copy files from dir2 to dir3 and only allow overwrite of newer files

Then rename dir1 and dir2 to backup names and symbolically link dir1 and dir2 to dir3

That way you can access the files from either the dir1 or dir2 directory but there will only be one file so you have no syncing issues.

[PVR]

Hi !

Chris:- We need this solution for an application.

John:- If I do a rsync from dira to dirb, then we are not syncing based on time stamps. we need to update the old file with new file. I think we may need to write some scripts for this.

Thanks for your help.

[Muthukumar_5]

Use this script to do it.

#!/bin/ksh

# User input
dir1="" # input here
dir2="" # input here

for file in `find ${dir1} -type f`
do

sfile=`basename $file`
echo "${file} <- sync -> ${dir2}/${sfile}"
syncfile=$(find ${dir2} -name ${sfile} -newer ${file} -print)

# Sync operation
if [[ ! -z ${syncfile} ]]
then
dstfile=`basename ${syncfile}
cp -fp ${syncfile} ${dir1}/${dstfile}
echo "Sync operation done"
else
cp -fp ${file} ${dir2}/${sfile}
echo "Reverse Sync operation done"
fi

done

# END
exit 0

hth.

[TwoProc · Accepted solution]

Actually,

I've tested it, and rsync does indeed sync based on time stamps, as well as file size, and file content.

[PVR]

Thanks a ton John....It worked.