Mailman List Membership Changes

In this example, we report changes in GNU Mailman list memberships, both by count, also by doing a diff against the previous list membership.

The MailmanListMembershipChanges script might send an alert message like the following:

                                PIKT ALERT
                         Thu Sep 15 14:52:47 2005
                                  moscow

INFO:
    MailmanListMembershipChanges
        Report changes in Mailman list memberships.

        for emf-announce, current membership is now 1777, was 1775
        < [email protected]
        ---
        > [email protected]
        118a119
        > [email protected]
        434d434
        < [email protected]
        748d747
        > [email protected]
        1053d1051
        > [email protected]

        for emr-comm, current membership is now 347, was 346
        > [email protected]

The script follows.

MailmanListMembershipChanges

        init
                status =piktstatus
                level =piktlevel
                task "Report changes in Mailman list memberships."
                input proc "=mailmanbindir/list_lists | =egrep -iv matching"
                dat $list 1
                keys $list

        rule    // initialize for current list
                set #changed = #false()

        rule    // determine current list membership
                set #mbrs = #val($command("=mailmanbindir/list_members $list | =wc -l"))

        rule    // determine if membership changed
                if #mbrs != %mbrs
                        output mail "for $list, current membership is now $text(#mbrs),
                                     was $text(%mbrs)"
                        set #changed = #true()
                fi

        rule    // if changed and have list history, mv to backup
                if #changed
                        if -e "=hstdir/mailman/$list"
                                =execwait "=mv =hstdir/mailman/$list
                                               =hstdir/mailman/$list\.piktbak"
                        fi
                fi

        rule    // save current membership in the histories/mailman directory
                if ! -d "=hstdir/mailman"
                        =execwait "=mkdir =hstdir/mailman; =chmod 750 =hstdir/mailman"
                fi
                =execwait "=mailmanbindir/list_members $list > =hstdir/mailman/$list"

        rule    // if changed, and we have a backup of the previous
                // list, diff the current against the previous,
                // else dump the current list
                if #changed
                        if -e "=hstdir/mailman/$list\.piktbak"
                                =outputproc(mail, "=diff =hstdir/mailman/$list\.piktbak
                                                         =hstdir/mailman/$list | =tail +2")
                                output mail =newline
                        else
                                =outputfile(mail, "=hstdir/mailman/$list")
                                output mail =newline
                        fi
                fi

This is just one program example.  You could write new scripts, for example to:  monitor and report problems with Mailman list configurations, report failures to archive list messages, etc.

For more examples, see Samples.