As well as windows Y MacOS is another of the most widely used operating systems worldwide.. Which consists of software that allows you to use programs such as editors of , Internet browsers, games, etc. Thus, it is characterized by a multi-user and multi-tasking system which provides an interface and a graphical interface.
However, as it is a system designed primarily for work in , The security of the information that each user stores on their computers and on servers is essential. Taking into account that many people will have access to part of the software and hardware resources that are managed through computers.
As a consequence, in linux There are things known as “permissions or rights of users” that are directed to certain files contained in the machines and, for this, they are established at three different levels, among which are owner permissions. To know more What are they and how can they be changed?We invite you to read this post.
What are permissions and owners in the Linux operating system?
In general terms, a permit consists of an authorization that obtained or granted to carry out a certain process. Therefore, permissions and owners in Linux are defined as a set of privileges that are granted based on who can read, modify or execute a system-specific file.
Now, the owner is the user who create or produce a file or folder within your workspace or in some other directory to which you have rights. Therefore, from the owner’s permissions of the system, each person will have the power to create the files they want within their working directory, by default, on linux.
For its part, to be clear about these concepts, it should be noted that in network systems there is always the figure of the administrator or superuser. said individual, is responsible for registering or deregistering other users and even takes care of establishing the privileges that each of them will have in the system. One of these privileges is owner permissions.
What is the role of permissions and owners in this OS?
To understand the role of permissions and owners in linux, it is necessary to note that each file in this OS is identified by 10 characters that define the type of file it islike the permissions granted to the ownerrespectively.
However, at a global level, three types of permissions are the most managed and, below, we mention what they are and what their specific nature is:
PERMIT TYPE
ID
Without permission
–
read permission
r
write permission
w
permission of execution x
Now, knowing the types of permissions that are handled in linux, it’s possible define what function they fulfill and/or what they are for.
This information is mentioned below:
file permissions
- read permissions: Provides the possibility of viewing the content of the file, solely and exclusively.
- write permissions: Allows you to change or modify the content of the file in question.
- execution permissions: As the term itself indicates, they allow the file to be executed as if it were executable software.
Directory permissions
- read permissions: It is useful to know what files the directory that has that privilege contains.
- write permissions: These permissions work to support the creation of files in the directory, both new and regular. You can even move, copy and delete files in the directory.
- execution permissions: Allows you to browse all the contents of the directory, as well as copy files to or from it. In the event that read and write permissions are also obtained, in addition, all possible operations can be performed on directories and files.
Learn how to modify permissions and owners in Linux
Although it is true, to be able to change permissions and owners of files or folders in the systems Linux/Unixit is necessary to have access to the line of commands. Noting that, there are two exclusive commands that you can use to accomplish this task, but we will only focus on chmod.
Next, we show you the steps to follow to make this modification:
Take a look at the syntax of the Linux chmod command.
Basically, the chmod It’s about a command used to change permissions of a File, Archive either binder.
Considering that, each file has three types of users that can interact with it and they are the following:
TYPE
DESCRIPTION
owner
Consists of the user who created and owns a file or directory.
group
Corresponds to all users who are members of the same group
Others
Refers to other users in the system who are not owners or members of the group
Now, there is a specific formula to correctly use the command chmod.
Next, we detail what the precise syntax is:
- chmod … MODE… FILE…
- chmod …MODE-OCTAL FILE…
form an octal number
Now the combination of values of each group of usersyou will have to form a number octal. From this foundation, the combination of bits on or off in each group can be obtained, especially with eight possible combinations of values.
For example, the probable sums of the bits on are:
PERMISSION
OCTAL VALUE
DESCRIPTION
– – – You don’t have any permission – – x 1 Execute permission only – w – 2 Write permission only – wx 3 Write and execute permissions r – – 4 Only read permission r – x 5 For read and execute permissions rw – 6 For read and write permissions rwx 7 All permissions set; i.e. read, write and execute
Sets the permissions of the file or directory
Taking the above information, when user, group and other permissions are combined, can you get a three digit number which, basically, are what make up the permissions of the file/directory.
This way:
PERMISSION
WORTH
DESCRIPTION
rw– ––– –—
600 Owner has rwx read and write permissions ––x-–x 711 Owner read, write and execute, group and others execute only rwx rx rx 755 Owner read, write and execute, group and others can read and execute the file rwx rwx rwx 777 File can be read, written and executed by whoever r–– ––– –— 400 Only the owner can read the file, but neither the owner can modify or execute it and of course neither the group nor others can do anything on the rw- r-– ––– 640 Owner user can read and write, group can read the file and others can’t do anything
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