Re: [Dovecot] compression script for use with zlib module

Hi,

I´m using the following two scripts:

zip-list.sh:

find "$home"
-type f
-name '*,S=*'
-mtime +1
-size +10k

The above script list the files that will be compressed.

zip-compressh.sh #!/bin/bash

uid='vmail' gid='vmail'

sleepOnFailure='2'

cat zip-list.txt|while read i do if [ ! -f "$i" ] then continue fi

    type=$(file -bi "$i")
    fgrep 'message/rfc822' <<<"$type" >/dev/null
    if [ "$?" != '0' ]
    then
            continue;
    fi

    echo -n "$i..."

    modify=$(stat -c %y "$i"|cut -d. -f1)
    basename=$(basename "$i")

    gzip -9 -c "$i" >/tmp/"$basename"

    mv /tmp/"$basename" "$i"
    exitStatus="$?"
    while [ -f "$i" -a "$exitStatus" != '0' ]
    do
            echo -n "wait($sleepOnFailure)..."
            sleep "$sleepOnFailure"
            mv /tmp/"$basename" "$i" 2>/dev/null
            exitStatus="$?"
    done

    chown "$uid"."$gid" "$i"
    touch -m -d "$modify" "$i"

    echo "OK"

done

This script reads the zip-list.txt and compress the file. We do not lock the maildir, but we use touch to maintain original dates. We do not check any 'Z' flags.

[]s Fernando

Hi,

I'm wondering if someone already implemented a compression script

(and would like to share it) based on the step-by-step provided on wiki page of Zlib module.

I can already do some find|xargs gzip .... but couldnt implement it

completly as described on the wiki page. I know the suggested step-by-step is very detailed and probably a must simplier will be enough for almost anyone .... anyway, if someone have the full script and would like to share it, i would be glad to get it :)

http://wiki.dovecot.org/Plugins/Zlib

1. Find the mails you want to compress in a single maildir.
2. Compress the mails to tmp/ the original files (e.g. touch command)
   • Update the compressed files' mtimes to be the same as they were in
3. Run maildirlock <path> <timeout>. It writes PID to stdout, save it. directory, if it's separate)
   • <path> is path to the Maildir's dovecot-uidlist (the control
   • <timeout> specifies how long to wait for the lock before failing.
4. If maildirlock grabbed the lock successfully (exit code 0) you can continue.
5. For each mail you compressed:
   1. Verify that it still exists where you last saw it.
   2. If it doesn't exist, delete the compressed file. Its flags may have been changed or it may have been expunged. This happens rarely, so just let the next run handle it.
   3. If the file does exist, rename() (mv) the compressed file over the original file. * Dovecot can now read the file, but to avoid compressing it again on the next run, you'll probably want to rename it again to include e.g. a "Z" flag in the file name to mark that it was compressed (e.g. 1223212411.M907959P17184.host,S=3271:2,SZ). Remember that the Maildir specifications require that the flags are sorted by their ASCII value, although Dovecot itself doesn't care about that.
6. Unlock the maildir by sending a TERM signal to the maildirlock process (killing the PID it wrote to stdout).

--

Atenciosamente / Sincerily, Leonardo Rodrigues Solutti Tecnologia http://www.solutti.com.br

Minha armadilha de SPAM, NÃO mandem email gertrudes@solutti.com.br My SPAMTRAP, do not email it