#!/bin/bash
set -a
VERSION=1.0
shopt -s nullglob
USAGE="${0##*/}"' [options] arguments ...
reads a config file (default: /etc/sympa-archives-expire) and removes old 
archives for the listed SYMPA mailing lists.
See http://colas.nahaboo.net/Software/SympaArchiveExpire

The file should list the SYMPA mailing list archives to expire after N months
in the form:
  listname@hostname N
N is optional (default 1) and mean the number of full month archives to keep
  e.g. if N=2, the current month and the full two months before will be
  kept, older ones will be deleted
lists not listed in this file never expire
empty lines and lines beginning with # are ignored

The file should be run under the sympa account, once a day

Options:
  -c FILE   Uses FILE instead of /etc/sympa-archives-expire
  -d DIR    Sympa installation dir, defaults to /home/sympa
  -n        Do not perform cleanups, just list what it would have done

'"Version: $VERSION"

listfile=/etc/sympa-archives-expire
DIR=/home/sympa
real=true

# Options processing
while test "_${1#-}" != "_$1" -a "_${1//-/}" != "_";do case "$1" in
  -c) listfile="$2"; shift;;
  -d) DIR="$2"; shift;;
  -n) real=false;;
  *) echo "$USAGE"; exit 1;
esac;shift; done; if test "_$1" = "_--";then shift; fi


# we calculate dates in months since AD: 
# year with 0 appended in base 12 + month
# d2m 2008-07 => 41575
d2m () { let m="(12#${1%%-*}0)+10#${1#*-}"; echo $m; }
nowd=`date +%Y-%m`
now=`d2m $nowd`

# $1=listname $2=dir/file name
mark_to_rebuild () {
  if $real
    then rm -rf "$2"
    else trace "To remove: in $1, $2"
  fi
  >"/tmp/sympa-archives-expire.rebuild.$1"
}

err () { echo "***ERROR: $*" >&2; exit 1; }
warn () { echo "===WARN: $*" >&2; }
trace () { echo "$*" >&2; }

if test ! -e $listfile; then err "Config file $listfile not found"; fi

egrep -v '^[ 	
]*(#|$)' <$listfile | while read list months; do
  let months="${months:-1}"

  if cd "$DIR/arc/$list" 2>/dev/null; then
    for i in [0-9]*; do
      m=`d2m $i`; let diff=now-m
      if let 'diff>months'; then mark_to_rebuild "$list" $i; fi
    done
  else warn "Directory not found: $DIR/$list"
  fi

  if cd "$DIR/expl/${list%@*}/archives" 2>/dev/null; then
    for i in log.[0-9]*; do
      ym=${i#log.}; m=`d2m ${ym%??}-${ym#????}`; let diff=now-m
      if let 'diff>months'; then mark_to_rebuild "$list" $i; fi
    done
  else warn "Directory not found: $DIR/expl/${list%@*}/archives"
  fi

done 

# tell sympa to rebuild the touched lists
for i in /tmp/sympa-archives-expire.rebuild.*; do
  if $real
  then >"/home/sympa/spool/outgoing/${i#/tmp/sympa-archives-expire}"
  else trace "To rebuild: ${i#/tmp/sympa-archives-expire}"
  fi
  rm -f "$i"
done