Linux instruction type (i) Change directive

I. Change instructions

Chattr

Chgrp

chmod

Chown

Chfn

Chsh

Chroot

Second, the CH instruction detailed introduction (1) chattr

Full Name: Change attribute

function: The chattr command is used to change file properties

Syntax: chattr [-RV][-v< version number >][+/-/=< Properties >][file or directory ...]

Parameters:

-R recursively handles all files and subdirectories under the specified directory.

-v< version number > set file or directory version.

-V Displays the instruction execution process.

+< Properties > Open the Item property of the file or directory.

-< Properties > Close the Item property of the file or directory.

The =< property > Specifies the Item property of the file or directory.

Property:

A: Make the file or directory available for additional use only.

B: Do not update the last access time of the file or directory.

C: Compress the file or directory and store it.

D: Exclude files or directories from dumping operations.

I: Do not alter the file or directory arbitrarily.

S: Privacy delete files or directories.

S: Update files or directories instantly.

U: Remove outside of prevention.

Example:chattr +i /etc/resolv. conf

(2) Chgrp

Full Name: Change Group

Role: The CHGRP command is used to change the owning group of a file or directory

Syntax:chgrp [-cfhrv][--help][--version] [affiliation Group] [file or directory ...]

or chgrp [-cfhrv][--help][--reference=< reference file or directory >][--version [file or directory ...]

Parameters:

The-C or--changes effect resembles the "-V" parameter, but returns only the part of the change.

-F or--quiet or--silent does not display an error message.

-H or--no-dereference only modifies the signed file, without altering any other related files.

-R or--recursive recursively handles all files and subdirectories under the specified directory.

-V or--verbose shows the instruction execution process.

--help online Help.

--reference=< reference file or directory > set all of the assigned files or directories to the same group as the reference file or directory.

--version Displays version information.

Example: Chgrp-v bin Log2012.log

ll #显示信息

(3) chmod

Full Name: Change mode

Role: chmod can be used to control how files are called by others

Syntax: chmod [-CFVR] [--help] [--version] Mode file ...

Mode: Permission set string, format such as: [Ugoa ...] [[+-=][RWXX] ...] [,...]

Mode parameter:

U represents the owner of the file, and G indicates that the owner of the file belongs to the same group (group), and O means the other person, and a means that all three are.

+ indicates an increase in permissions,-represents a cancellation permission, = Represents a unique set of permissions.

R means readable, w means writable, x is executable, x means only if the file is a subdirectory, or the file has been set to executable.

Additional parameter Description:

-C: If the file permission has changed, it will not show its change action

-F: Do not display an error message if the file permissions cannot be changed

-V: Show details of permission changes

-r: The same permissions change for all files in the current directory as subdirectories (that is, they are changed in a recursive manner)

--HELP: Show Auxiliary Instructions

--version: Display version

Example: chmod ugo+r file1.txt

chmod +x test.sh

(4) Chown

Full Name: Change owner

Role: Chown The owner of the specified file to the specified user or group, the user can be either a user name or a user ID, a group can be a group name or a group ID, and a file is a space separate list of files to change permissions, and wildcard characters are supported.

Limitation: Only the system administrator (root) has this permission.

Syntax: chown [-CFHVR] [--help] [--version] user[:group] File ...

Parameters:

User: The user ID of the new file owner

Group: The user group of the new file owner (group)

-C: If the file owner does change, the change action is displayed

-F: Do not display an error message if the owner of the file cannot be changed

-H: Changes to the link only, not the file that the link really points to

-V: Show details of owner changes

-R: The same owner changes to all files in the current directory as subdirectories (that is, they are changed individually in a recursive manner)

--HELP: Show Auxiliary Instructions

--version: Display version

Example: Chown jessie:users file1.txt

(5) CHFN

Full Name:

Function: Used to change the information displayed by the finger command. This information is stored in the passwd file in the/etc directory. If you do not specify any options, the CHFN command enters the question-and-answer interface.

Syntax: CHFN [parameter] [user name]

Parameters:

-f< real name > or--full-name< real name;: Set real name

-h< Home Phone > or--home-phone< home phone: Set the phone number in your home

-o< Office Address > or--office< Office Address: Set Office Address

-p< Office Phone > or--office-phone< Office Phone: Set the office phone number

-U or--help: Online Help

-V or-version: Displays version information.

Example: CHFN
Chfn-f Jack.

(6) Chsh

Full Name: Change shell

Role: The CHSH command is used to change the user shell settings.

Syntax: chsh [parameters] [Shell path]

Parameters:

-S or--shell: Changes the system preset shell environment.

-L or--list-shells: Lists the shell lists available for the current system

-U or--help: Online Help

-V or-version: Displays version information.

Example: Chsh

Chsh-s/bin/zsh

(7) Chroot

Full Name: Change root

Role: The chroot command is used to change the root directory.

Syntax: chroot [--help][--version][destination directory] [execution instructions ...]

Parameter description:

--help online Help.

--version Displays version information.

Example: Chroot/mnt/ls//changing root directory

Linux instruction type (i) Change directive