Server should be SSL-aware but has no certificate configured [Hint: SSLCertificateFile] ((null):0)

The above error appears with recent versions of apache (>2.2.13) despite the fact that apache has SSLCertificateFile and other SSL configuration correctly set. Not sure what is the problem, but the solution is quite simple but difficult to find, specially most people with that error have wrong ssl configuration, but if you are sure it is not your case and you’ve correctly configured SSL options for apache you might try to replace
Listen 443 with Listen 443 http

Awstats SkipHosts all records dropped

Awstats is a very nice log file analyzer, written in perl, does produce website statistics. However recent perl (>5.14.0) upgrade broke most of the configuration options of awstats version 7.0, as a consequences awstats is dropping all record when using SkipHosts options, which is an option to tell awstats to don’t include specific host (like localhost, 192.168.**, etc…).
Many other options are broken as well, see this link for more details.

You can use this patch, alternatively a patched archlinux package of awstats can be found here which includes also the missing swf.png file from the original package, if you want you can just use this repository with pacman

[archost]
Server = http://repo.archost.org

 

Archost alpha release

Archost is an open source hosting control panel written in php and designed for archlinux based servers. Archost is not aimed to be a classic hosting control panel (admin, reseller, client), it is a control panel aimed to ease server administration for hosting personal, family, friends and company websites and mails.

Archost comes with an installer to ease server configuration, please see archost web page for more details

Maxima, Computer Algebra System

Maxima is a computer algebra system that can be used to perform many computation, i did not know that it exists until recently, it is simply amazing.

I never used maple, because it is a “closed to control users” software, and even when i wanted to just try it, the version provided at my university for free for students did not work under my archlinux, it was freezing up after 2,3 seconds.

Maxima can do a lot, the nice thing also is that it has emacs support, just install maxima+emacs, open emacs then M-x imaxima for latex style or maxima for normal style: you need to add it to the load path of emacs, you can do that by adding the following lines to your $HOME/.emacs

(add-to-list 'load-path "/usr/share/maxima/5.23.2/emacs/")
 (autoload 'maxima-mode "maxima" "Maxima mode" t)
 (autoload 'imaxima "imaxima" "Frontend for maxima with Image support" t)
 (autoload 'maxima "maxima" "Maxima interaction" t)
 (autoload 'imath-mode "imath" "Imath mode for math formula input" t)
 (setq imaxima-use-maxima-mode-flag t)

Replace “/usr/share/maxima/5.23.2/emacs/” with the correct path of your installation
 

Here is a screenshot of the latex style (imaxima):

You can write function, macros, … and put them in $HOME/.maxima/, the you can load a specific file by calling load (“filename”).

In octave, resolution of linear system define by matrices can be done by doing A\b, where A is the matrix of the variables coefficient, and b is the rvalue (A.X=b), there is no such thing in maxima, however writing this is very easy, here is what i did:

 

msolve(M,X,b):=block([R],
    s: M.X,
    list: makelist(s[i, 1] = b[i, 1], i, 1, length(s)),
    listX: makelist(X[i, 1], i, 1, length(X)),
    R: solve(list,listX),
    return(R))$

Also one very important feature is that at any point you can call tex() on a specific variable and you will get the latex code that you can use directly in a latex document, you can use these lines in your latex document:

\documentclass[leqno]{article}
\usepackage{amsmath} 
\usepackage{amsfonts}
\usepackage{setspace}
\usepackage{verbatim}
\usepackage[cmbase]{flexisym}
\usepackage{breqn}
\setkeys{breqn}{compact}
\setlength{\textheight}{200cm}
%%%%%%%%%% IMAXIMA  %%%%%%%%
\setlength{\textwidth}{180mm}
\setlength{\oddsidemargin}{15mm}
\addtolength{\oddsidemargin}{-1in}
\setlength{\evensidemargin}{15mm}
\addtolength{\evensidemargin}{-1in}
 
\newcommand{\ifrac}[2]{\frac{#1}{#2}}
\newcommand{\ifracd}[2]{\frac{#1}{#2}}
\newcommand{\ifracn}[2]{\frac{#1}{#2}}
\newcommand{\isubscript}[2]{{#1}_{#2}}
\newcommand{\iexpt}[2]{{#1}^{#2}}
\newcommand{\isqrt}[1]{\sqrt{#1}}
\begin{document}
....
\end{document}

Note that, imaxima might use an old style latex code (like \pmatrix instead of \begin{pmatrix}) but these you can replace easily, once you get the tex code from maxima with tex() call.

Xfce Power Manager to core

Xfce’s session and Xfce power manager both use power operations, there is a lot of upower/consolekit/polkit duplicated code in these tow packages, after a discussion on xfce’s mailing list about the future 4.10 release plan, we came to the point that xfce power manager should provide a dbus session service that can be used to do power operations, this service will be used by xfce’s session without having to write the same code in two places, this means that xfce power manager will no longer be an addon package of Xfce, it’ll be a part of the core distribution starting from the Xfce 4.10 release, see the 4.10 roadmap for more details.

One benefit from this change is having a Xfce wide configuration of power operations, since the xfce power manager dbus service will be the common place for power configurations.

Parole, the new version

I’ve been working on a completely new version of Parole, this is the new interface of the player

The IP you’re using to send mail is not authorized to 550-5.7.1 send email directly to our servers.

Recently i started having problem with my own hosted mails, i’m no longer able to send mails directly from my server, checking postfix mail.log when sending mails to gmail revels this error


The IP you’re using to send mail is not authorized to 550-5.7.1 send email directly to our servers. Please use the SMTP relay at your 550-5.7.1 service provider instead.

As usual, googling this error will shows a lot of useless results and forums posts with people asking the guy having the problem, Do you have reverse dns set ? Check your spf record, etc…

Reverse dns can only be set for static ip addresses, which is my case, any mail server running with a dynamic ip addresses has to relay its mails to another smtp server, because the mails will go to the spam, so people that with dynamic ip addresses should not ask why the mails are not passing.

For the spf record is nothing to do with the problem, so having a static ip with reverse dns with correct spf it is hard to find the solution out of all these useless forums posts.

The problem is just that spamhaus blacklisted your ip for some reason, it can be because they blacklisted a list of ip addresses that they are not typical for servers, or maybe your server is misconfigured and have been used as a spam source, you can check in their site to see what is the problem, and you can proceed for a request to remove your ip addresses from the blacklist, it is recommended to do that only if you really need, in my case i do need since i host a group ware that uses mails to notify users, once you do the removal request (they ask you to have a mail addresse hosted at your own, ie user@yourserver, so you should have a correct mail server), the removal takes about 30 minutes and you’ll be able to send mails again.

Xfce Power Manager 1.0.0

fce Power manager version 1.0.0 have been released, this version is based completely on upower, means that batteries information are read from upower daemon, upower is also used for hibernate/suspend operations, polkit is an optional requirement for the new version, since it helps the power manager to figure out if the user is authorized to do some actions, if you are not able to use suspend/hibernate and you are sure that your laptop can do suspend/hibernate, then you need to check your polkit authorizations, usually the setup are done by you distribution provider, but if you are compiling from source then see man pklocalauthority for more details, but as a quick howto get authorizations you need to create authorization files in /var/lib/polkit-1/localauthority/50-local.d

for example, org.freedesktop.upower.pkla will contains

[Local Users]
Identity=unix-user:YOUR_USER_NAME
Action=org.freedesktop.upower.*
ResultAny=yes
ResultInactive=no
ResultActive=yes

Create as well another file for consolekit (used for shutdown) Action org.freedesktop.consolekit.* and for udisks (used for spinning down the hard drive when on battery power) with Action org.freedesktop.udisks.*

With the new version xrandr is the backend used to handle display brightness, but HAL support can be enabled at compile time to be used as a fallback in case xrandr fails to handle the backlight panel (which is the case for losts graphic cards, unfortunately :-(

_NET_WM_WINDOW_OPACITY_LOCKED hint.

Almost all modern window managers have compositing capabilities, this is nice, but in the other hand it is very annoying for softwares like image viewers or media players…

The _NET_WM_WINDOW_OPACITY_LOCKED hint tells the window manager that the opacity is locked on a specific window, so the window manager would use this hint to keep the window opaque, unfortunately this hint is not standardized yet, but the Xfce’s window manager supports it, so here is how to set this hint on a top level widget, the widget has to be realized of course.

static void
set_wm_window_opacity_locked (GtkWidget *widget)
{
    Display *xdisplay;
    GdkScreen *gdkscreen;
    GdkDisplay *gdkdisplay;
    GdkWindow *gdkwindow;
 
    Atom atom;
    char mode = 1;
 
    gdkscreen = gtk_widget_get_screen (widget);
    gdkdisplay = gdk_screen_get_display (gdkscreen);
 
    xdisplay = GDK_DISPLAY_XDISPLAY (gdkdisplay);
 
    atom = XInternAtom (xdisplay, "_NET_WM_WINDOW_OPACITY_LOCKED", TRUE);
 
    /*Check if the atom is valid */
    if ( atom == None )
        return;
 
    gdkwindow = gtk_widget_get_window (widget);
 
    XChangeProperty (xdisplay, GDK_WINDOW_XID (gdkwindow),
                     atom, XA_CARDINAL,
                     32, PropModeAppend,
                     (guchar *) &mode, 
                     1);
}

Or even simpler

static void
set_wm_window_opacity_locked (GtkWidget *widget)
{
    GdkWindow *gdkwindow;
    GdkAtom atom;
 
    char mode = 1;
 
    atom = gdk_atom_intern ("_NET_WM_WINDOW_OPACITY_LOCKED", TRUE);
 
     /*Check if the atom is valid */
    if ( atom == None )
        return;
 
    gdkwindow = gtk_widget_get_window (widget);
 
    gdk_property_change (gdkwindow,
                         atom,
                         gdk_x11_xatom_to_atom (XA_CARDINAL),
                         32,
                         GDK_PROP_MODE_APPEND,
                         (guchar *)&mode,
                         1);
}