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Archives pour 02/2024

Aide-mémoire administrateur Linux

24/02/2024 Comments off

administrateur linuxCe document rappelle les commandes et les options les plus utilisées par l’administrateur d’un système Linux. Il s’agit surtout de commandes assez générales, dont tout administrateur aura besoin un jour ou l’autre. Les commandes pour l’utilisateur courant se trouvent dans un autre aide-mémoire. Pour plus d’informations, on consultera les pages de manuel ou les publications du Linux Documentation Project

Une version prête à l’impression recto-verso est disponible pour conserver cet aide-mémoire dans un format facile à ranger dans un tiroir ou sous un clavier.

Informations système

uname – Identification du système.

  • -a : toutes les informations.

dmesg – Messages du noyau (et ceux du boot).

uptime – Durée et charge du système.

free – Occupation de la mémoire.

vmstat – Détails sur l’utilisation de la mémoire.

ipcs – Utilisation des ressources IPC System V.

ipcrm – Suppression de ressources IPC System V.

ldconfig – Valider les bibliothèques dynamiques.

init – Changement de niveau de fonctionnement :

  • 0 : arrêt.
  • 1 : mono-utilisateur,
  • 3 : multi-utilisateurs mode texte,
  • 5 : multi-utilisateurs mode graphique,
  • 6 : redémarrer.

Utilisateurs

useradd – Ajout d’un utilisateur :

useradd -m -p "" linus

crée un compte linus, avec répertoire personnel et mot de passe vide.

Lire la suite…

Remove a Person From a Photo With Photoshop CS5’s Content Aware Feature

24/02/2024 Comments off

Source: tutsplus.com

Final Product What You’ll Be Creating

With the launch of the new Adobe Suite of programs comes the long awaited Adobe Photoshop CS5. Packed with new features to speed up your workflow it truly is the most advanced edition of Photoshop to date. One of the new features we will be looking at today is called Content Aware. This feature allows you to quickly fill in a selection with surrounding content making it look like a part of the original image. In this case we will choose to remove a person from a photo, this can be done in less than five minutes. With the additional image enhancements this tutorial will take you less than 10 minutes to complete.

 


Original Image

Before we begin, download the image that we will be working with. As you can see, there are two individuals in this photo. In today’s tutorial, we will use Photoshop CS5′s Content Aware Feature to remove the man on the left.


Step 1

Using the content aware tool on different images produces different results. An image with a gradient background such as the sky in this image is quite tricky to work with. Open beach.jpg in Photoshop.


Step 2

We are extracting the person on the left from this photo. Using the Pen Tool, (P) Begin by making a path around the subject. The nice thing about using content aware is that you do not have to be exact when making a selection. In fact, do your best not to cut too close to the subject.

Notice in the image below how far I am drawing the path from the subject. Try to keep this distance all the way around. If you go too close, Content Aware will take pixels from the subject. If you cut too far it will take pixels from the woman on the right.


Step 3

Once you complete the path around the subject, turn it into a selection. This can be done by right clicking on the path and selecting Make Selection.

A dialog box will pop-up, make sure the feathering is set to 0px. Leave all other options as they are. Click OK.


Step 4

Now we have an active selection around our subject. In this step we will make the subject disappear from the image using Content Aware Fill. To do this, go to Edit > Fill.

A dialog box will pop-up, make sure the Content Aware option is selected. Blending mode is set to normal and the opacity is at 100%. Hit OK.

You can cancel the selection at any time by making another selection or just clicking anywhere else on the page with any selection tool.


Step 5

In this step we will remove some of the other artifacts in the image using the same process. The content aware tool did miss a spot where the subject’s foot originally was. To do this, draw a rectangle around the area using the rectangle selection tool. And use the content aware fill as we have done in the previous steps.

Now let’s remove the people towards the right of the image. Create a rectangle selection around them and use the steps we just demonstrated to remove them.


Step 6 (Optional)

Using the Crop Tool (C) lets crop the image so that the focus is drawn to the woman jumping. To do this, just crop out an area of the image that you would like to keep. Beware of the shadow that is left behind from the person that we have removed. You can use the Content Aware feature to remove this shadow but I have decided to crop it out altogether.

Click the checkmark at the top to keep this area. Photoshop will discard the content that is outside of your crop area.


Step 7 (Optional)

In this step we will enhance the photo by giving it a more vibrant look. The colors currently appear somewhat dull. There are many ways to accomplish this but we will use Color Curves. To do this, go to Image > Adjustments > Curves, (Cmd + M). A dialog box will pop-up and we will select each of the channels, R, G, B and work on them separately. Select the Red channel from the dropdown menu.

We are going to make two points on the graph. One in the bottom of the top right square, and one in the top of the bottom left square.

Once you have made these points, make sure you enter the values for each. For the top right point the Output value is 199, and the input value is 185. For the bottom point the values are 56 and 68, respectively. You can play around with these setting and adjust them to whatever you feel is appropriate. Repeat this for each of the colors, Green and Blue.


Final Image

Your image should now look something like the one seen below. As you can see, we have removed the man on her left with very little effort using Photoshop CS5′s new Content Aware Feature.

Categories: Logiciel Tags:

Configurer une Freebox pour autoriser une connexion VPN à un routeur DD-WRT

23/02/2024 Comments off

Source: Autour de… Sam

Autour de… Sam
freebox-revolutionLa question revient assez souvent pour se connecter à distance chez soi au travers un VPN quand on dispose d’un routeur sous DD-Wrt derrière une box ADSL.
Dans le cas que vais expliquer ci-dessous, je prendrai le cas d’une Freebox V4 et d’une Freebox V6.

Il faut tout d’abord savoir que DD-Wrt embarque un très bon parefeu et que nos box ADSL françaises sont aussi équipées d’un parefeu quand elles sont en mode routeur et non pas en mode passerelle (gateway ou bridge). Lire la suite…

Categories: Réseau, Système Tags: ,

Trucs et astuces d’utilisation de SSH

23/02/2024 Comments off

Source: Lone Wolf $cripts

SSH est l’acronyme de Secure SHell. Il s’agit historiquement du remplaçant de Telnet. Telnet est l’outil utilisé pour dialoguer simplement avec un serveur. Sa force : il peut se connecter à n’importe quoi ou presque. Ainsi, un fou utilisant telnet peut envoyer des emails (protocole SMTP), lire des pages Web (protocole HTTP), remettre sa montre à l’heure (protocole NTP), etc… Son inconvénient majeur : toutes les informations circulent en clair sur le réseau, mots de passes compris. A une époque, telnet était utilisé pour ouvrir une session à distance sur un serveur… imaginez le cauchemard. SSH est un outil dédié à l’ouverture de sessions à distances via une connexion sécurisée. Pour faire simple, SSH est à telnet ce que HTTPS est à HTTP : une version chiffrée et sécurisée. Cet article présente certaines des subtilités de SSH. Lire la suite…

Configuring Log Rotation of Apache2 and Other Logs

22/02/2024 Comments off

source: lifeonubuntu.com

I went to check out my apache2 logs

ls /var/log/apache2/

and I noticed that they were being automatically rotated (access.log, access.log.1, etc.) and compressed with gzip (access.log.2.gz, etc.). This seems to be the default Ubuntu configuration. I wanted to make find out more, and I found this helpful article about Ubuntu logs, including Apache2 Log info and some basic log rotation info.

After reading through the info, I decided that I wanted to make a few changes. The log rotation happens via the brilliantly named logrotate command. It turns out that logrotate settings kept in 2 places. Lire la suite…