Ytdyklly

I have a script that iterates through a given directory and automatically compresses those that do not contain at least one file used in less than 30 days. Now, I am wondering if I could improve performance by using find together with exec. I tried something, but it is not working. Do you have any suggestions?

#!/bin/bash

# find all the directories

dirs=`find . -type d`

# iterate every file in every directory

for dir in $dirs

do

        n="totar"

        # search all the file in the directory

        files=`find $dir -type f -atime -30`

        for file in $files

        do

                n="keepasis"

        done

        if [ $n == "totar" ]; then

                tar -zcvf $dir.tgz $dir

                rm -r $dir

        fi

done

My idea was to replace the second for loop with something like:

find $dir -type f -atime -30 -exec n="keepasis" {} ;

If you set a variable in find's -exec action this will not be visible.

The fact that find has found a file and printed its name is sufficient to decide that you don't want to archive the directory. So you don't need the for file in $files loop, instead check that $files is not empty.

If your find command supports the -quit action you can use this to stop after the first match. (see How to stop the find command after first match?)

Instead of putting the output of the first find into a variable and using a for loop with word splitting you should better read find's output lime by line.

#!/bin/bash

# find all the directories

# -mindepth 1 prevents "find" from printing "."

find . -mindepth 1 -type d | while read -r dir

do

    # a subdirectory might no longer exist if a parent has been archived before

    if [ -d "$dir" ]

    then

        # search any new file in the directory

        newfilefound=`find $dir -type f -atime -30 -print -quit`



        if [ -z "$newfilefound" ]

        then

            tar -zcvf $dir.tgz $dir

            rm -r $dir

        fi

   fi

done

If you are using bash you can improve the first find to correctly handle more directory names with special characters: find . -type d -print0 | while IFS= read -r -d '' dir; do...

There is still a performance issue:

If a directory contains a new file somewhere in a subdirectory you don't remove it. Later you will get all subdirectory names down to the one with this file. In this case you will use find several times to find the same new file.

The only solution that comes to my mind is to use two find, some post-processing and one fgrep:

1. Let one find print the names of all new files, process the output by removing the file names, printing all the parent directories as separate lines and removing duplicates and putting the list into a file NEWDIRS.


2. With a second find print all directory names to a second file ALLDIRS.


3. Use fgrep to find all lines from ALLDIRS that don't match a line in NEWDIRS.

You should check that the tar command was successful before removing the directory.