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Shell script to compare and delete files

I have two trees under the directories

/usr

and

/bak/usr

I would like to use a command or a short bash script that will
delete everything under /bak/usr which exists and has the same
date and relative path as a file under /usr. How would I do this?

Thanks in advance,
Nicholas Waltham

ASKER CERTIFIED SOLUTION

mlev

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nwaltham

ASKER

Hello - thanks for your script. Its possible /bak/usr could have newer files, since its from a different system. I guess the modification to the script would only need to be slight...

mlev

You can make the 7th line read
if [ -e "$bakfile" -a ! "$file" -nt "$bakfile" -a ! "$file" -ot "$bakfile" ]
but then identical directories won't be removed, since their date will change as their contents are removed. To solve this:

#!/bin/sh

find /usr -depth |
while read file
do
bakfile="/bak$file"
if [ -e "$bakfile" -a ! "$file" -nt "$bakfile" -a ! "$file" -ot "$bakfile" ]
then
echo "$bakfile"
fi
done |
while read bakfile
do
if [ -d "$bakfile" ]
then
rmdir "$bakfile" 2>/dev/null
else
rm -f "$bakfile"
fi
done

Please note that even this way, in some cases directories still won't be removed e.g. because their date changed last time you ran this script. Maybe you should think of a different criterion for directories than date (e.g. empty and exist in both /bak/usr and /usr)

nwaltham

ASKER

Thanks for your help!