https://stephane.lesimple.fr/wiki/ 2026-05-03T16:35:19+00:00 https://stephane.lesimple.fr/wiki/ https://stephane.lesimple.fr/wiki/lib/tpl/incognitek/images/favicon.ico text/html 2010-03-08T13:25:31+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/accelerating_firefox_s_rendering_time ====== Accelerating Firefox's rendering time ====== If you use <color purple>Firefox</color> as your daily browser, and you're not using <color purple>Indic</color> or any <color purple>CJK</color> script as your Firefox locale, you can disable the <color purple>Pango</color> renderer, which makes Firefox support these languages, but also make it (much) slower. Before disabling Pango, i've loaded a big HTML page (the PHP reference) in Firefox, and watched the CPU time used by Firefox when the … text/html 2010-03-08T13:25:31+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/additional_repositories_for_yum_and_their_cohabitation ====== Additional repositories for Yum and their cohabitation ====== <color red>yum</color> comes by default with 3 repositories: * core, contains exactly the same packages that are on your installation CD * updates, the core packages but updated on a regular basis * extras, semi-official repository maintained by volunteers (the community) But you can - and should - add other (unofficial) repositories. The most important one is Livna, it contains a lot of multimedia stuff (graphic cards… text/html 2010-03-08T13:25:31+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/apache_logical_or_and_conditions_with_setenvif ====== Apache logical OR & AND conditions with SetEnvIf ====== Unfortunately, the [[http://httpd.apache.org/docs/2.2/mod/mod_setenvif.html#setenvif|Apache SetEnvIf module]] doesn't support logical conditions, like ''OR'' & ''AND''. More specifically, it is not possible to set a variable only if <color navy>''condition1''</color> ''AND/OR'' <color navy>''condition2''</color> are verified. For example, to [[http://httpd.apache.org/docs/2.2/mod/mod_log_config.html#customlog|log]] all the POST que… text/html 2010-03-08T13:25:31+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/back_online ====== Back online ====== Well, after almost 3 years of hiatus, I finally managed to find the time to : * Move my blog from my old ISP web space to here * Upgrade serendipity to the latest version, install and configure zillions of plugins * Find a decent theme * Get that bloody syntax highlighting to look respectable * Migrate the old posts to the new install, using aforementioned syntax highlighting * etc. Expect some new posts in the not too disant future. :) ~~META:date cre… text/html 2010-03-31T07:48:07+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/collectd_and_grsecurity ====== collectd and grsecurity/PaX ====== I recompiled [[http://collectd.org|collectd]] some days ago, to get the latest version : 4.9.1. When I tried to restart it, I was greeted with a nice error message: <code> # /etc/init.d/collectd start Starting statistics collection and monitoring daemon: collectd lt_dlopen (/opt/collectd/lib/collectd/netlink.so) failed: file not found Unable to load plugin netlink. # ls -l /opt/collectd/lib/collectd/netlink.so -rwxr-xr-x 1 root root 26K 2010-03-30 23:4… text/html 2010-04-10T22:30:36+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/compiling_the_nvidia_and_virtualbox_modules_for_all_available_kernels ====== compiling the nVidia and VirtualBox modules for all available kernels ====== I like to keep some old kernel versions around, just in case. The problem is that their manually compiled modules are often not kept up to date by Fedora (notably VirtualBox modules and nVidia's blob). So here are the two commands I use to do just that manually: nVidia's blob (as packaged by RPMusion) uses the akmod system, so this is pretty straightforward: <code> # for d in /lib/modules/* ; do akmods --kerne… text/html 2010-03-09T14:07:23+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/compress_vs_gzip_vs_bzip2_vs_lzma_vs_lzma2_aka_xz_benchmark ====== compress vs gzip vs bzip2 vs lzma vs lzma2 aka xz benchmark ====== **Edit:** A more recent and more complete benchmark is available : [[lzop_vs_compress_vs_gzip_vs_bzip2_vs_lzma_vs_lzma2-xz_benchmark_reloaded]] I discovered the <color red>''xz''</color> compression algorithm some weeks ago. It's derived from LZMA, which is quite effective. Recent <color red>''tar''</color> versions even include support for this algorithm, and the official [[ftp://ftp.gnu.org/gnu/coreutils/|GNU FTP serve… text/html 2010-03-08T13:25:31+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/dev_shm_is_better_than_tmp ====== /dev/shm is better than /tmp ====== One often has to use temporary files to store temporary data, and this is often done under UNIX using the <color green>''/tmp''</color> directory (or <color green>''/var/tmp''</color> directory). Well, it works, but the <color green>''/tmp''</color> directory is a real directory on your hard drive (at least on Linux), and if you really need to use temporary stuff, it's not really interesting to put it on your hard drive. Nowadays we have a lot of RAM … text/html 2010-04-28T22:57:24+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/fixing_a_locale-archive_breakage ====== Fixing a locale-archive breakage ====== If you are greeted with the following errors when trying to use <color orangered>perl</color>: <code console> $ perl -e '' perl: warning: Setting locale failed. perl: warning: Please check that your locale settings: LANGUAGE = (unset), LC_ALL = (unset), LANG = "en_US.UTF-8" are supported and installed on your system. perl: warning: Falling back to the standard locale ("C"). </code> Or when using <color orangered>yum</co… text/html 2010-03-08T13:25:31+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/get_the_amount_of_remaining_ink_of_your_epson_printer ====== Get the amount of remaining ink of your Epson printer ====== This is how to get the amount of remaining ink as reported by your Epson printer. For KDE: <code sh> #! /bin/sh # LANG=C is to be sure that it works on all locales kdialog --title "Ink levels" --msgbox "$(LANG=C escputil -qir /dev/usb/lp0 2>&1 | \ sed -re 's/.*remaining.*/Percent of ink remaining/;s/([0-9]+)$/\1%/')" </code> For Gnome: <code sh> #! /bin/sh # LANG=C is to be sure it works on all locales zenity --info --title… text/html 2010-03-08T13:25:31+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/getting_rid_of_selinux_labels ====== Getting rid of SELinux labels ====== Even if I'm using Fedora, I'm not very fond of <color purple>''SELinux''</color>. I find the policies to be way too complicated to customize, and it seems one just have to cope with the policies made by the distributor, and barely have any chance to adapt it. They even bundle <color red>''setroubleshootd''</color> on Fedora, which will happily ask a desktop applet to pop up and try to explain the user what <color purple>''SELinux''</color> did just bl… text/html 2010-03-08T13:25:31+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/how_to_efficiently_use_yum_offline ====== How to efficiently use Yum offline ====== I use Fedora on my laptop, and at first I had a couple of problems with <color red>**''yum''**</color>, which seems to always believe you're connected to the Internet. There a special switch : <color purple>**''-C''**</color>, but it didn't work all the time with me. I was used to <color red>**''apt-get''**</color> before, which updates its metadata only if you tell it to (via <color red>**''apt-get update''**</color>). To configure <color red>**… text/html 2010-03-08T13:25:31+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/how_to_launch_the_correct_associated_program_for_any_file_from_the_console ====== How to launch the correct associated program for any file from the console ====== Let's say you have a .png file, a .txt file and an .mp3 file. If you are using Konqueror (or Nautilus under Gnome), just double click, the program you've chosen for this type of file will be launched : a picture viewer for the .png file, a text viewer for the .txt file, and a multimedia player for the .mp3 file. Now, you're using the console, and you don't want to bother wondering which program you want t… text/html 2010-03-08T13:25:31+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/how_to_make_graphical_applications_work_with_sudo ====== How to make graphical applications work with sudo ? ====== If you use <color red>sudo</color>, you may have noticed that, with Fedora Core 5, you just can't exec a graphical application as root (for example) if you haven't actually logged in as root in your X environment (you never do that ! Do you ?). You have probably encountered this type of message : <code console> $ sudo kcalc Xlib: connection to ":0.0" refused by server Xlib: Invalid MIT-MAGIC-COOKIE-1 key kcalc: cannot connect t… text/html 2010-03-08T13:25:31+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/kernel_2.6.18_linux_config.h_problem ====== Kernel 2.6.18 linux/config.h problem ====== If you want to compile a kernel module with the new 2.6.18 kernel, you may encounter this error message: <code console> linux/config.h: No such file or directory </code> This may happen even if you have your kernel headers installed (having your whole kernel sources won't help either). This is because the module you're trying to build requires the <color green>''linux/config.h''</color> file, which has been deprecated for some time now, and h… text/html 2010-03-08T13:25:31+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/konqueror_is_more_than_explorer.exe Konqueror is more than explorer.exe ... Indeed ! I was playing around with <color purple>Konqueror</color>'s options, and found that it supports a couple of interesting protocols. As you may already know, Konqueror is <color purple>KDE</color>'s default browser, and also serves as the KDE's file browser, a la explorer.exe under Windows (even if it hides a bit behind iexplore.exe, which is really Internet Explorer, but that's not the point here). text/html 2010-04-27T22:50:51+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/listening_to_multi-channel_audio_with_only_two_speakers_in_stereo_using_mplayer ====== Listening to multi-channel audio with only two speakers in stereo using mplayer ====== Have you already noticed while listening to multi-channel music with only two stereo speakers with <color orangered>''mplayer''</color>, how the sound is low ? Same thing applies with videos using the <color purple>''AC3''</color> format, often composed of 5 channels. Mplayer, being the swiss-army knife of video players, gives you the tools to deal with multi-channel audio with your two poor laptop sp… text/html 2010-04-02T14:54:25+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/lzop_vs_compress_vs_gzip_vs_bzip2_vs_lzma_vs_lzma2-xz_benchmark_reloaded ====== lzop vs compress vs gzip vs bzip2 vs lzma vs lzma2-xz benchmark, reloaded ====== I've had a couple of interesting comments at my [[compress_vs_gzip_vs_bzip2_vs_lzma_vs_lzma2_aka_xz_benchmark|last attempt]] to benchmark those algorithms.\\ So, here is a more complete benchmark, with hopefully more detailed results. ===== Benchmark protocol ===== We are benchmarking all the algorithms supported by recent <color red>tar</color> versions (1.22 was used): ^ program ^ extension ^ version ^ c… text/html 2010-03-09T18:13:20+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/main ====== Fedora & Linux Tips ====== //Some random stuff that one may find useful...// ====== Posts ====== <blog list> blog default tpl smallish cache 0 sortby created limit 6 </blog> <blog pagination> blog default </blog> You can also get a **[[blog:meta:list_of_all_posts|list of all posts]]** Telnet-compliant tag cloud: <blog tagcloud> blog default limit 50 target blog:meta:tags </blog> <blog newform> title add a new page blog default format blog:%{titl… text/html 2010-03-08T13:25:31+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/playing_around_with_rpms_and_the_rpm_command ====== Playing around with RPMs and the rpm command ====== <color purple>RPM</color> is the package manager format used on Fedora Core (it's also widely used on others). It stands for Red Hat package Manager (well, who cares anyway). You probably already know you can install or uninstall RPMs, but you can do way more than that. RPM is the filename extension of individual packages you can install, but it's also the name of the whole underlying system that keeps track of what's installed on your … text/html 2010-03-08T13:25:31+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/proxytunnel_1.9.0_enhanced ====== Proxytunnel 1.9.0 enhanced ====== I recently discovered [[http://proxytunnel.sourceforge.net/|Proxytunnel]], a great tool to build tunnels through HTTP and/or HTTPS proxies, which is even able to chain two proxies. It can seem a bit overkill at first sight, but it's really useful in some configurations. This tool is well documented on its homepage and a very nice use case is detailed [[http://dag.wieers.com/howto/ssh-http-tunneling|here]]. I made a patch (named <color purple>''-sl1''</… text/html 2010-03-08T13:25:31+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/quick_and_effective_way_to_disable_the_pc_speaker ====== Quick and effective way to disable the PC speaker ====== Well, I don't like when my PC goes beep-beep at 2 a.m. and everybody is sleeping !\\ So I've found a radical way to disable it: simply forbidding Linux to load the PC speaker kernel module. Edit <color green>''/etc/rc.local''</color> and add : <file> rmmod pcspkr </file> That's it.\\ If you want to disable it right now simply type the same line in a terminal, as root (or use sudo): <code console> # rmmod pcspkr </code> ~~MET… text/html 2010-04-28T09:16:52+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/samba_user_shares_broken_on_fedora_12 ====== Samba user shares broken on Fedora 12 ====== If you're using Samba user shares on your system (that is, shares that users can mount without being root), you were probably greeted with the following message for the last several weeks, when trying to mount a share: <code console> $ mount nas This mount.cifs program has been built with the ability to run as a setuid root program disabled. mount.cifs has not been well audited for security holes. Therefore the Samba team does not recommend i… text/html 2010-03-08T13:25:31+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/search_the_path_for_any_missing_libraries ====== Search the PATH for any missing libraries ====== The following command will search for all the binaries located in your <color blue>''$PATH''</color> and tell you if any program is missing some shared libraries (.so) to be able to run correctly. I often use it after a distro upgrade: <code console> # find $(echo $PATH | tr : '\n' | sort -u | tr '\n' ' ') -mindepth 1 -maxdepth 1 -type f -perm /111 -print0 | xargs -r0 ldd | egrep 'not found|:$' | grep -B1 'not found' </code> Output examp… text/html 2010-03-08T13:25:31+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/sound_problems_with_games_using_oss ====== Sound problems with games using OSS ====== Some Linux games (in fact, most) are still using <color purple>OSS</color>, namely Enemy Territory or Quake III Arena for example. Even if your sound subsystem is well configured (either with real <color purple>OSS</color> or with <color purple>ALSA</color>'s <color purple>OSS</color> emulation), you may encounter a "no sound" problem under these games. Sometimes there's an error message associated: <code console> /dev/dsp: Input/output error C… text/html 2010-03-08T13:25:31+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/the_right_way_to_use_iptables_under_fedora_core ====== The right way to use iptables under Fedora Core ====== Fedora Core comes with a 2.6 kernel, which comes in turn with <color red>iptables</color>. Some other distributions require you to use your own way of loading rules on boot (for example, a script), but Fedora Core comes with an easy way to do it. Note that the way I'm going to describe is **not** compatible with the simple firewall GUI launched via: <code console> $ system-config-securitylevel </code> Both ways are mutually exclusi… text/html 2010-03-08T13:25:31+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/upgrade_from_fc5_to_fc6 ====== Upgrade from FC5 to FC6 ====== This day has finally come ! Fedora Core 6, codenamed <color purple>Zod</color>, is out. If you have Fedora Core 5 already installed, you may want to upgrade. I'll not tell you here what's new and everyhing, you can find that a bit everywhere on the Internet. Just google for it ! Note that upgrading with <color red>yum</color> is not officially recommended by the Fedora Project. This is because it generally works, but MAY also go wrong, and when this happen… text/html 2010-03-08T13:25:31+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/using_sudo_to_avoid_typing_the_root_password_all_the_time ====== Using sudo to avoid typing the root password all the time ====== When you're installing your new Linux system, you very often need to launch commands as root. The right way to do it in the console is: <code console> $ su - Password: </code> After entering the password, you'll be root. When you're done with the root commands, just type <color red>exit</color>. Now, if you just need to type ONE command as root, this is pretty boring : first, "<color red>su -</color>", then "your command… text/html 2010-03-08T13:25:31+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/what_if_you_don_t_want_utf-8_as_a_default ====== What if you don't want UTF-8 as a default ? ====== <color purple>UTF-8</color> is great, I mean, this is wonderful. The problem is, it's not yet well supported, and most of the stuff I have is in <color purple>Latin1</color> (aka <color purple>ISO-8859-1</color>), and not <color purple>UTF-8</color>. That's why I would like all my apps to have <color purple>Latin1</color> as a default. I haven't found a straightforward way to tell that to Fedora and/or KDE and/or Linux. So I had to make… text/html 2010-03-08T13:25:31+00:00 Anonymous (anonymous@undisclosed.example.com) https://stephane.lesimple.fr/wiki/blog/yum_plugin_to_show_installed_package_versions_when_upgrading ====== Yum plugin to show installed package versions when upgrading ====== There is a feature <color red>''apt-get''</color> has and <color red>''yum''</color> misses : the ability to show installed packages versions, when asking confirmation about upgrading. There is a list of the about-to-be-installed packages version numbers, but not the already installed versions. For example yum might tell you that you're about to upgrade to apache v2.2.14-2, but from which version ? If you're upgrading f…