Linux file permission settings: symbolic representation VS numerical representation, which one do you prefer?

File permission settings are quite critical, directly affecting the rights to access, modify, and execute files. Here I would like to introduce two different setting methods as well as my personal experience and opinionsLinux Setting permissions on files, I hope I can give you some suggestions for your reference.

Allow us to first review the basics of Linux file permissions warmly. Every file has three basic permissions: read (r), write (w) and execute (x). These permissions can be assigned appropriately to the owner, group and remaining users.

Please allow me to give you a brief introduction to symbolic representation. When using this method, we need to remember: "r" means read-only, "w" means writable, and "x" means it has execute permission. In addition, we can also grant additional permissions through plus sign(), or cancel corresponding permissions through minus sign(-). As for the user type, "u" represents the owner's Linux system, "g" represents the group to which it belongs, and "o" represents other users.

Another method is to use numerical representation. When using this method, you need to remember that "r" is 4, "w" is 2, and "x" is 1. Just add up the various permission values ​​to get the required number. Among them, the first digit represents the permissions of the owner, the second digit represents the permissions of the group to which it belongs, and the last digit represents the permissions of other users!

Next, let’s take a look at the similarities and differences between these two permission setting methods. The symbolic representation is relatively simple and clear, easy to understand and remember; while the numerical representation is more rigorous, only one number can summarize all permissions, and at the same time, the required permissions can be calculated.

Solinux sets permissions for files, which expression method do you think is more appropriate? If you prefer to be direct and easy to remember and only need to implement a few basic permission settings, symbolic representation may be a good choice for you; and when you are good at calculating and using numbers, or often need to perform complex permission settings, numerical representation Law may be more suitable.

Please take a look at this example to demonstrate how to use two methods to set permissions. Suppose there is a "myfile" file, and you want to give the owner read, write, and execute permissions, the group you belong to read and execute permissions, and exclude other users from any rights. Use symbols to represent rules, and just run the following commands to achieve the corresponding functions:

```

chmod u rwx,g rx,o-rwx myfile

If you choose to use numeric notation, you can run the following command:

chmod 754 myfile

There are some common issues that need to be paid attention to. For example, how to let the owner and the group share the same permissions? How to quickly adjust the permissions of multiple files in batches? When you set file permissions, you can make good use of wildcards to help you modify the permissions of multiple files more easily. For example, with the powerful function of `chmod u rwx *.txt`, you can give the owner full read, write and execute permissions for all your txt files!

Next, let’s talk about security issues. Properly setting file permissions can help prevent unauthorized use and malicious behavior. Be sure to grant only necessary permissions, and regularly check and correct file permission settings.

After comparing the respective advantages and suitable usage environments of the two representation methods, we found that you can freely choose symbolic or numerical representation according to your personal preferences and actual needs. Please note that no matter which expression form you choose, be sure to set file permissions correctly to ensure the security of your system!

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