Linux Learning Notes-permissions and permissions management

Permissions and Permissions Management

Rights Management:

R:

W:

X:

Three types of users:

U: Owner

G: Genus Group

O: Other users

Chown: Change file owner (only administrators can use this command)

# chown USERNAME File,...

-R: Modify the owner of the directory and its internal files

--reference=/path/to/somefile,... Specify the file or directory as the reference and set the operation's file or directory to the same

Chown username:grpname File,... At the same time change the owner of the file, and the name of the group

Chown USERNAME. GRPNAME file,... At the same time change the owner of the file, and the name of the group

#chgrp GRPNAME file,... Change the file genus Group

-R : Recursively modifies the genus of directories and their internal files

--reference=/path/to/somefile,... Specify the file or directory as the reference and set the operation's file or directory to the same

chmod: Modify permissions for a file

Modify permissions for three categories of users:

chmod MODE File,...

-R: Recursive modification

--reference=/path/to/somefile,...

To modify the permissions of a class of users:

U,g,o,a

chmod [u,g,o,a]=mode file,...

Modify some or some bit permissions for a class of users:

U,g,o,a

chmod [U,g,o,a]+|-mode file,...

Umask: Masking Code

#:umask 022

$:umask 023

Files: 666-umask

Catalog: 777-umask

The file cannot have Execute permission by default, and if the result has Execute permission, it will add 1 to its permission;

User's login:

The type of shell that stands in the user's Landing angle:

Log-in Shell:

Log in normally via a terminal

Su-username

Su-l USERNAME

Non-logon shell:

Su USERNAME

Open Command Window under graphics terminal

Shell scripts that are executed automatically

Bash configuration file:

Global configuration:

/etc/profile,/etc/profile.d/*.sh,/ETC/BASHRC

Personal configuration:

~/.bash_profile, ~/.BASHRC

File for Profile class:

Setting Environment Variables

Run a command or script

Files of the BASHRC class:

Setting Local Variables

Defining command aliases

How does the login shell read the configuration file?

/etc/profile-->/etc/profile.d/*.sh--~/.bash_profile-/ETC/BASHRC

How does a non-logon shell read a configuration file?

~/.BASHRC--/ETC/BASHRC-/etc/profile.d/*.sh

BASH: script interpreter

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Linux Learning Notes-permissions and permissions management