Get list of files group by Date

Question

I have a directory with files coming for every day. Now I want to zip those files group by dates. Is there anyway to group/list the files which landed in same date.

Suppose there are below files in a directory

-rw-r--r--. 1 anirban anirban    1598 Oct 14 07:19 hello.txt
-rw-r--r--. 1 anirban anirban    1248 Oct 14 07:21 world.txt
-rw-rw-r--. 1 anirban anirban  659758 Oct 14 11:55 a
-rw-rw-r--. 1 anirban anirban    9121 Oct 18 07:37 b.csv
-rw-r--r--. 1 anirban anirban     196 Oct 20 08:46 go.xls
-rw-r--r--. 1 anirban anirban    1698 Oct 20 08:52 purge.sh
-rw-r--r--. 1 anirban anirban   47838 Oct 21 08:05 code.java
-rw-rw-r--. 1 anirban anirban 9446406 Oct 24 05:51 cron
-rw-rw-r--. 1 anirban anirban  532570 Oct 24 05:57 my.txt
drwxrwsr-x. 2 anirban anirban      67 Oct 25 05:05 look_around.py
-rw-rw-r--. 1 anirban anirban   44525 Oct 26 17:23 failed.log

So there are no way to group the files with any suffix/prefix, since all are unique. Now when I will run the command I am seeking I will get a set of lines like below based on group by dates.

[ [hello.txt world.txt a] [b.csv] [go.xls purge.sh] [code.java] ... ] and so on.

With that list I will loop through and make archive

tar -zvcf Oct_14.tar.gz hello.txt world.txt a

Answer 1

If you have the GNU version of the date command, you can get the date of modification of a file with the -r flag, which can be very useful. For example, given the file list in your question, date +%b_%d -r hello.txt will output Oct_14.

Using this, you could loop over the files, and build up tar files:

• If the tar file doesn't exist, create it with a single file
• If the tar file exists, add the file to it
• After the loop, zip the tar files

Like this:

#!/usr/bin/env bash

tarfiles=()

for file; do
    tarfile=$(date +%b_%d.tar -r "$file")
    if ! [ -f "$tarfile" ]; then
        tar cf "$tarfile" "$file"
        tarfiles+=("$tarfile")
    else
        tar uf "$tarfile" "$file"
    fi
done

for tarfile in "${tarfiles[@]}"; do
    gzip "$tarfile"
done

Pass the list of files you want to archive as command line parameters, for example if /path/to/files is the directory where you want to archive files (listed in your question), and you save this script in ~/bin/tar-by-dates.sh, then you can use like this:

cd /path/to/files
~/bin/tar-by-dates.sh *