Tag: permissions

By Christopher P Wakefield

This time we are going to have a look at Linux permissions. Every current operating system deals with permissions, whether it is ownership of a file or just gaining read access to a folder. As with everything else in Linux there are command line tools and the graphical user interface so we shall discuss both.

chown --helpThe Chown Utility

This is a command line tool that deals with the ownership of a file or folder. Open up a terminal and switch to root. Navigate to the directory which contains the file / folder you want to change and type:

chown [username][file /folder]

So for example if I wanted to change the owner of a file called tools to natasha and it was located in /home/chris I would type:

cd /home/chris

chown natasha tools

To check who owns a particular file / folder you can navigate to the directory that contains the file / folder and type:

ls -l

The Chmod Utility

Next up is the chmod utility which deals with permissions themselves. Open up a terminal and switch to root. Navigate to the directory which contains the file / folder you want to change and type:

chmod [777][file / folder]

Lets first explain the numbering system above. There are three types of permissions in Linux – Read, Write and Execute which are given values of 4, 2 and 1 respectively. So in the syntax above the file would be given Read (4), Write (2) and Execute (1) permissions (4+2+1 = 7). But don’t you give permissions to people and not files or folders? Correct, that is why there are three numbers which represent the owner, group and others. Lets take an example to illustrate the point. Say I wanted to change the permissions of a file called tools.doc to owner (rwe), group (rw) and others (r) and it was located in /home/chris I would type:

cd /home/chris

chmod 764 tools.doc

This gives the owner (rwe = 7) group (rw = 6) and others (r=4) different levels of access to the file.

Graphical Means of Changing Permissions and Ownership

For people who don’t want to use the command line there is another way to do all this. I shall illustrate this using Linux Mint 9. Locate the file you want to alter by using your file manager. Right click and go to open as root. In Linux Mint 9 the background will go red when a file is open as root. Right click and go to properties. On the properties page you will be given the option of changing permissions for the owner, group and others along with changing the owner of the file. Change accordingly.

Hi I am Chris the owner of ComTech. I provide IT support to both personal and business clients from my base in Alloa, Clacknmannanshire. Here at ComTech I am experienced in using Windows, Linux and Cisco technologies whether it be for the home or business. I also incorporate Blackberry hardware into my business, namely the Blackberry Playbook and Bold 9780. I can advise, design and implement solutions to any problems you may have so if you have IT issues just pick up the phone. Please go to http://www.comtech247.net for more information.

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Beginners Under Gnu – Linux? There Are Five Errors to Be Avoided
By Didier Pradel

To give the desire for testing linux so that it is one day your operating system, is one of the objectives of this site. The new users of GNU/Linux often make the same errors when they test GNU/Linux for the first time. The reasons of these errors are numerous: because GNU/Linux is a different OS; because Windows gives bad habits; because the user chooses the bad distribution and much of other possibilities. Here some solutions with five current problems under GNU/Linux.

1- To choose its distribution:

There is much opinion on the GNU/Linux distribution with which you will have to start, and the majority are not relevant.

After having to seek, to study, read the opinions of users, with the wire of time, on many distributions, two points arise:

the first: GNU/Linux Bureau is a question of taste,

the second: not a distribution does not join together the whole of the best options.

For start with GNU/Linux, it is to advise to choose among the following distributions, without small-sol-figure02-icon-montageorder:

Professional SUSE and, in the future, openSUSE

Linspire Xandros

Fedora Core

Mandriva (in the past Mandrake)

Ubuntu

2- Is Linux free?

Some claim that all that is related to Linux is free. A good software deserves that one pays for him it is obvious, but the price must be reasonable the majority of the commercial distributions GNU/Linux for the office costs less than $100 and is really very rich. The term distribution meaning that a great number of software are gathered they also contain thousands of applications for the office. The commercial distributions GNU/Linux include word processing softwares, P2P, spreadsheet, presentation on transparency, edition file sharing of video, binary compatibility with Windows, virtual machine, reading of DVD, Web server, Web navigator, and much of others.

3- The partitions:

With Windows, you are accustomed to only one partition on your hard disk. It contains the operating system, the applications, the data, and a great space for your file of Windows exchange (the software uses space on the hard disk when the read-write memory is not enough any more). GNU/Linux functions differently. In order to obtain the best performances of the system, the file of exchange is on a separate partition. If you have 512 MB or 1GB of read-write memory the size the partition of exchange (swap) should not be lower than 512 MB, and not lower than 1GB if you have less than 512 MB of read-write memory.

It is useless to make a larger partition if you use your machine only for office automation applications. With this solution you can safeguard the remainder of your personal and software data on a second partition. It is a good solution if you never change hard disk or operating system. But if you wish to preserve your data and the preferences of the applications which you use, it is to better do two other partitions for the operating system, the other for your data and your adjustments. that thus gives 1 partition root “/”, 2 partition “/home”. 3 swap the size depends on the number of software which you install, but 20 GB are more than sufficient for the partition root “/”root, the largest part of your disc must be to hold has” /home “, because it is there that you will store images, films, and other large files. It is wise to give 75% of the total disk space to the repertory /home, the majority of the GNU/Linux distributions can make the partitions for you, but they have all various ideas on the number of partitions to create and their size. you must decide if you want to change the default values. You can preserve your Windows partition and thanks to the dual-boot to choose to start your computer either under Windows or under GNU/Linux. You must install Windows in first to make only one partition but not too large not to obstruct the installation of GNU/Linux after. And if you want to exchange files between the Windows partition and the GNU/Linux partition, use the filing system FAT32 to format your Windows partition (Window does not read the partition linux and linux does not read partitions NTFS whereas it can read and write easily on a system FAT32).

4- The Permissions:

With Windows, you are in general either an administrator, or a user with the rights of administrator. With GNU/Linux, you are in general connect as a user to restricted access, and you pass as a root (i.e. administrator under Windows) when you must change important parameters of the system or regulate the hardware configuration or add or remove a program. This organization based on the permissions makes your system protected and one is accustomed quickly, although that is strange at the beginning.

5- To give up with the first problems:

GNU/linux is not Windows thus you enter a new world with new rules. To learn has to evolve/move in this new world will take time, it is normal. It will be necessary to learn from new software, a new interface, with a new manner of making. but once passed this stage hardest is made. The community the forums are sources of support as well as the site of your distribution if you chose a distribution commercial. To learn an operating system is a challenge. Essayer Linux is not in fact so hard and a thing is sure in any case: more you are frustrated with Windows and its problems, more the transition to GNU/Linux will be easy. Good luck! Those which want to install linux on a laptop will find here The linux laptop support a list of the laptop on which that was already done.

Didier Pradel is the webmaster of laptop support and The linux laptop support where you can find many useful informations, and help for your lovely laptop.

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