When you install Apache HTTP on CentOS, mod_filter is not enabled by default then if you try to use some of its directives an error like this is raised: "Invalid command 'FilterDeclare', perhaps misspelled or defined by a module not included in the server configuration", so to resolve the above error is enough to add the following line to the httpd.conf.
Activate mod_filter in Apache on CentOS Read More »
I have installed the basic packages of the XFCE desktop, by typing:
$ sudo apt-get install xfce4The above command installs some packages that I do not use as: Orage so I typed:
$ sudo apt-get purge orage
...
The following packages will be REMOVED:
orage* xfce4*
...
Do you want to continue[Y/n]? y
P. Now every time I try to install an application apt-get show a message that there are packages that were installed automatically, and which are not required but they are essential packages to keep my desktop running correctly. How to resolve this?
R. You must change the state of those packages from automatic installation to manual installation by typing:
$ sudo apt-mark manual paquete1 paquete2 ...– man apt-mark
Change the state of package from automatic to manual Read More »
The obfuscated XML files are difficult to read because the content of the file occupies a single line. Today LibreByte offers 3 tools that allow you to format an XML file.
Tool 1: web browser, examples: Mozilla firefox, Google Chrome. The disadvantage of using a browser is that you can not edit the XML file, only useful if you if you want to view it and nothing more.
Tool 2: use xml_pp, xml_pp is part of the XML-Twig suite, to install it on Debian GNU/Linux type:
$ sudo apt-get install xml-twig-tools
You can then format the XML file by typing:
$ xml_pp -i mifichero.xml
If you want to save the formatted content in another file, type:
$ xml_pp mifichero.xml > mifichero_pp.xml
If you want to edit the formatted file, you can use any text editor.
Tool 3: Use Geany editor and prettyprinter plugin, to install it on Debian GNU/Linux type:
$ sudo apt-get install geany geany-plugin-prettyprinter
After running the above command, you must perform the following steps to activate the plugin
1. Run Geany
XFCE:
Menu-> Development-> Geany
From the console, you can also type:
$ geany &
2. Find the Menu
Tools -> Plugin Manager
3. Activate the plugin XML PrettyPrinter
Once the plugin is activated, the option to format XML appears in the Menu:
Tools-> PrettyPtrinter XML
– man xml_pp
– Geany Project
– XML-Twig
– Geany un IDE ligero
How to pretty print XML on GNU/Linux Read More »
Some DVD player do not support video in high definition resolution then it is necessary to convert it to a supported format, so
* Look for your DVD player specifications
* Look at the details of the video file that you want to convert using MediaInfo
* Use a video conversion tool, in this case we will use avconv which is part of the Libav suite
The following example assumes that your DVD supports:
* Video mpeg4 simple profile format,
* mp3 audio format
* 720 frame size (width) by 576 (high).
$ sudo apt-get install libav-tools libmp3lame0
$ avconv -i fichero-origen -f avi -vtag divx -c:v mpeg4 -c:a libmp3lame -s:v 720x576 -aspect 16x9 -qscale 3 fichero-destino
where:
-f, the destination file format, usually avconv guess the format from the extension of the destination file
-vtag, specifies that we will use fourcc divx video codec to mpeg4 (Simple Profile)
-c:v, video code that will be used during the conversion
-c:a, code of audio that we will use during the conversion
-s:v, the frame size
-aspect, aspect and ratio that will have the resulting file. Is recommended to be the same as the original file to achieve good picture quality
-qscale, value between 1-31. A value of 1 means that the resulting file will have the same quality as the original file
– man avconv
Convert video file to watch on a DVD player Read More »
If when you try to unpack a file .tar.bz2, you get the following error messages:
tar (child): bzip2: Cannot exec: No such file or directory tar (child): Error is not recoverable: exiting now tar: Child returned status 2
You must solve it by installing the bzip2 package
# apt-get -y install bzip2
– man tar
Failed to decompress file .tar.bz2 Read More »
To copy a range of lines from a file to another:
1. Open the file in VIM
$ vim fich
2. Execute the following command within the editor (press Esc while in insert mode)
:num-sup-line,num-inf-linew! file-name
Example:
:10,50w! file-name
Further reading
– help write
Copy a range of lines from a file to another Read More »
MediaInfo is an utility that allows you to:
The following is the information dumped by MediaInfo:
MediaInfo supports following formats:
MediaInfo can be used through its graphical interface, command line interface or integrated into an application using the API.
$ sudo apt-get install mediainfo
$ mediainfo buffers_listed_and_hidden.ogv
General ID : 280403682 (0x10B69EE2) Complete name : buffers_listed_and_hidden.ogv Format : OGG File size : 4.61 MiB Duration : 3mn 28s Overall bit rate mode : Variable Overall bit rate : 186 Kbps Writing application : ffmpeg2theora-0.25 SOURCE_OSHASH : 3fd514e6b64347ca Video ID : 889190165 (0x34FFF715) Format : Theora Duration : 3mn 28s Bit rate : 89.5 Kbps Nominal bit rate : 297 Kbps Width : 640 pixels Height : 480 pixels Display aspect ratio : 4:3 Frame rate : 30.000 fps Compression mode : Lossy Bits/(Pixel*Frame) : 0.010 Stream size : 2.22 MiB (48%) Writing library : Xiph.Org libtheora 1.1 20090822 (Thusnelda) Audio ID : 1236641633 (0x49B5A761) Format : Vorbis Format settings, Floor : 1 Duration : 3mn 28s Bit rate mode : Variable Bit rate : 80.0 Kbps Channel(s) : 2 channels Sampling rate : 44.1 KHz Compression mode : Lossy Stream size : 1.99 MiB (43%) Writing library : libVorbis 20090709 (UTC 2009-07-09)
– man mediainfo
– MediaInfo project
MediaInfo – detailed information of an audio or video file Read More »
The first version was released in November 1991, for the Amiga platform. A year later came the first version for UNIX. Its author, Bram Moolenar, was inspired by VI editor, very popular among the UNIX followers. Vim inherits the features of VI and adds new ones, being a 99% compatible with its predecessor when it starts in compatible mode.
Its development model under a GPL compatible license and the new built-in features made VIM gain a lot of followers very quickly becoming one of the most popular editors. Currently the most GNU/Linux distributions incorporate it as the text editor by default.
| From / to | Normal | Insert | Cmdline | Visual | Select | Ex |
| Normal | i, Shift i | :, /, ?, ! | v, Shift v, Ctrl v | gh, g Shift h, g Ctrl h | Shift q | |
| Insert | Esc | — | — | — | — | |
| Cmdline | Enter, Esc, Ctrl c | :start | — | — | — | |
| Visual | Esc, v | c, Shift c | : | Ctrl g | — | |
| Select | * | ** | — | Ctrl o, Ctrl g | — | |
| Ex | :vi | — | — | — | — |
* You can change from Select selection to Normal mode pressing one of the buttons ← → ↑ ↓
** You can enter in insert mode holding any printable character
Vim also has a user interface (gVim), which may be more friendly for beginners, however veterans administrators prefer use it in text mode
The latest stable version is the 7.4.x Also the binary is available for the following platforms: UNIX, MS-DOS / MS-Windows, Macintosh, Amiga, OS/2, Cygwin, other.
Schulz, Kim. Hacking Vim
http://en.wikipedia.org/wiki/Vim
VIM a powerful and flexible text editor Read More »
How to change the configuration of my keyboard in KDE to be able to write accented words?
Use the following procedure to change the setting of your keyboard in KDE.
Change keyboard layout in KDE Read More »
P. I installed the KDE desktop, but my preferred applications: Iceweasel and GIMP look horrible how to fix this?
R. In order your GTK+ 2.x and GTK+ 3.x applications have the same appearance as the native KDE applications you should install the following packages.
– gtk2-engines-oxygen
– gtk3-engines-oxygen
– kde-config-gtk-style
To do this, type the following command in Debian GNU/Linux
sudo apt-get install gtk2-engines-oxygen gtk3-engines-oxygen kde-config-gtk-style
then go:
1. Start Menu
2. Select System Settings (KDE 4) / Settings > System Settings (KDE 5)
3. Select Application Appearance
4. Set the options shown in the figure below
Appearance of GTK+ applications in KDE[/caption]
Integrate GTK applications in KDE style Read More »