/home/drscream

I’ve installed a debian machine with the grsec kernel from kernelsec.cr0.org. Everything looks good and working fine, after some time i’ve found out that update-grub doesn’t work anymore.

[root@grapefruit]:~ # update-grub
Searching for GRUB installation directory ... found: /boot/grub

So looking in the dmesg output we will see the problem is grub-probe:

Nov  7 23:07:57 grapefruit kernel: [96585.754724] PAX: From 127.0.0.6: execution attempt in: , ...
Nov  7 23:07:57 grapefruit kernel: [96585.761809] PAX: terminating task: /usr/sbin/grub-probe(grub-probe):20649, uid/euid: 0/0, ...
Nov  7 23:07:57 grapefruit kernel: [96585.769773] PAX: bytes at PC: 41 ...
Nov  7 23:07:57 grapefruit kernel: [96585.776171] PAX: bytes at SP-8: 0000000000000006 ...

Now it’s time to checking the pax flags of grub-probe, here we will see the default options:

[root@grapefruit]:~ # chpax -v /usr/sbin/grub-probe
---[ chpax 0.7 : Current flags for /usr/sbin/grub-probe (PeMRxS) ]---
 * Paging based PAGE_EXEC       : enabled (overridden)
 * Trampolines                  : not emulated
 * mprotect()                   : restricted
 * mmap() base                  : randomized
 * ET_EXEC base                 : not randomized
 * Segmentation based PAGE_EXEC : enabled

We should disable paging and segmentation based PAGE_EXEC:

[root@grapefruit]:~ # chpax -ps /usr/sbin/grub-probe

And, tadaaaaa, update-grub working:

[root@grapefruit]:~ # update-grub
Searching for GRUB installation directory ... found: /boot/grub
Searching for default file ... found: /boot/grub/default
Testing for an existing GRUB menu.lst file ...
   found: /boot/grub/menu.lst
Searching for splash image ... none found, skipping ...
Found kernel: /boot/vmlinuz-2.6.32.15-1-grsec
Updating /boot/grub/menu.lst ... done

Als Linux User ist man es irgendwie gewohnt ein command line tool zur Verwaltung von bestimmten Anwendungen zu verwenden. Doch naja unter Mac OS X vermisst man das einfach. Durch etwas Googlen hab ich es dann gefunden *juhu*:

cd /System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/
./airport -I

     agrCtlRSSI: -51
     agrExtRSSI: 0
    agrCtlNoise: -96
    agrExtNoise: 0
          state: running
        op mode: station
     lastTxRate: 54
        maxRate: 54
lastAssocStatus: 0
    802.11 auth: open
      link auth: wpa2-psk
          BSSID: 0:18:84:17:28:3a
           SSID: cienfuegos
            MCS: -1
        channel: 2

Da man das ganze sicher einfach nur ueber den Befehl airport verwenden moechte, linked man das ganze einfach nach /usr/sbin:

sudo ln -s /System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport /usr/sbin/airport

Yeaaa :-) Yesterday i’ve found a nice way to set an default value for bash variables.
I use this way if parameter 1 isn’t assigned by the user. Here a small example:

ip=${1-'10.1.1.1'}

If $1 isn’t assigned by the user the default 10.1.1.1 is set as value of $ip.

In mutt it isn’t so easy to move mails by pattern because the best solution is to move mails not in the mail client but with procmail or mailfilter. Here is a solution that works also in mutt:

Tag all mails by specific pattern:
Limit the mails that are displayed.

L

Tag messages matching a pattern.

T

Move all taged mails to destination:

s =INBOX.dest.here

With find you can everything but you must know it :)

find . -type d -empty

[drscream@havanna] ~/Pictures/upload
 % find . -type d -empty
./Artwork/html/thumb
./Artwork/Photography/html/thumb
./html/thumb

It’s so easy, i’ve only searched a day long for that easy result:-P

[drscream@havanna] ~
 % tclsh
% puts $tcl_version
8.4

Currently i’ve some problems with my router. The reconnect only work sometimes… . So i’ve started to write a small bash script, to check that connection. The script run every hour and start a reconnection if no pppoe connection is available.

#!/bin/bash
#--------------------------------------------------------------------
# $Id: checkIConnect,v 0.1 2008/02/11 17:17:26 drscream Exp $
# Copyright 2008 Frubar Network (drscream@frubar.net)
#--------------------------------------------------------------------

##
## main
##
errors=0
ns_ip=$(cat /etc/resolv.conf | sed 's/nameserver //g' | head -n 1)

## device check
$(/sbin/ip a s dev ppp0 > /dev/null 2>&1)
if [ $? -gt 0 ]; then
        echo "ERROR: Device not found!"
        let errors=$errors+1
fi

## nameserver, ping check
$(ping -c 4 $ns_ip > /dev/null 2>&1)
if [ $? -gt 0 ]; then
        echo "ERROR: Ping doesn't work!"
        let errors=$errors+1
fi

echo "Code: $errors"

if [ $errors -gt 0 ]; then
        echo "INFO: reconnect internet"
        /opt/fruky/bin/pppoe-restart
fi

Easy way to get the last day is to look if the next day is the first of the month. Now here are a small bash script thats show you the functionality:

if [ $(date -d tomorrow +%d) -eq 1 ]; then
    echo "OK: last day of the month"
else
    echo "NOK: not the last day of the month"
fi

Wer kennt es nicht, gerade wenn man viele Datein loeschen moechte:

Argument list too long.

Ein einfacher “workaround” ist das verwenden von xargs:

ls | xargs rm

( Vielen Dank an adminlife.net )