Shulou(Shulou.com)06/02 Report--

1. View the location of the directory as an operation

> pwd

two。 View the contents of files in the (current) directory

> ls / / list

> ls-l or ll / / displays the details of the file

> ls-al / / all shows the details of the file (including hidden files)

> ls-a / / shows all file names of the directory (including hidden files)

> ls [- al] directory / / View the file information of the specified directory

3. Directory switching

> cd directory name

> cd.. Or cd.. / superior directory switch

> cd. Or cd. / switch to the current directory

> cd ~ or cd / / switch directly to the user's home directory

4. User handoff

> su-or su-root / / switch to root Super Admin

> su normal user name / / switch to ordinary user

> exit / / return to the original user

There will be an overlay effect when users switch, so do not repeat the su action (su and exit are paired)

Zhangsan--- > root--- > zhangsan--- > root--- > zhangsan

5. Check who the current user is

> whoami / / displays the users currently in the operating system

> who am i / / displays the user information of the login system (has nothing to do with su)

6. Switch between graphical interface and command interface

> # init 3 / / switch to the command interface

> # init 5 / / switch to the graphical interface

7. View the executable file location corresponding to the instruction

Which directive

8. Output the file contents directly to the terminal

Cat files

9. Clear the screen

> clear

10. Directory operation

① create directory make directory

> mkdir directory name / / create a single directory

> mkdir-p newdir1/newdir2/newdir3 / / Recursively create multi-level directories

> mkdir dir1/dir2/newdir

> mkdir-p dir1/newdir2/newdir3

If the hierarchy of the new directory is greater than or equal to 2, the-p parameter is required.

If it's equal to one, you don't need it.

The absolute path method of mkdir / home/zhangsan/shandong / / relative to the root directory creates the shandong directory

② Mobile Directory move

> mv dir1 dir2 / / dir1 is moved to the dir2 directory

> mv dir1/dir2 dir3 / / dir2 is moved to the dir3 directory

> mv dir1/dir2 dir3/dir4 / / dir2 is moved to the dir4 directory

> mv / home/zhangsan/beijing / home/zhangsan/shandong / / absolute path: move beijing to the shandong directory

(all the target directories moved to are [existing])

③ directory renaming operation

The second parameter of the mv instruction is the new name, that is, the rename operation.

The name that exists is the mobile operation.

Mv is a [move and rename] merge instruction

> move mv dir1 newdir / / dir1 to the current directory and change its name to newdir

> mv dir1/dir2 dir3 / / dir2 move to the dir3 directory and change the name to the original name

> mv dir1/dir2 dir3/newdir / / dir2 move to the dir3 directory and change the name to newdir

④ copy (and rename) operation copy

-R recursive recursive

> copy cp-R dir1 dir2 / / dir1 to dir2, and change the name to the original name.

> cp-R dir1/dir2 dir3/newdir / / dir2 is copied to dir3, and its name is changed to newdir

> cp-R dir1/dir2 newdir / / dir2 is copied to the current directory and renamed to newdir

> copy cp dir1/filea dir2 / / filea to dir2, and change the name to the original name

> copy cp dir1/filea dir2/dir3/newfile / / filea to dir3 and change the name to newfile

⑤ delete operation remove

-f force forced

> rm file / / Delete file files

> rm-r dir / / Delete a directory

> rm-rf filename / / Recursive forced deletion of files (directories)

> rm-rf / / Recursively force deletion of the "/ slash" root directory

11. Simple operation of file

View the contents of ① files

> cat filename / / output all the contents to the terminal at one time

> more filename / / View the contents of the file line by line by typing enter

Q key to end the view

> less filename / / "up, down, left, right" keys to view the contents of each part of the file (support looking back)

Q key to end the view

> head-n filename / / View the first n lines of the file

> tail-n filename / / View the last n lines of the file

> wc filename / / View the number of lines in the file

② create File

> touch filename / / create a filename file in the current directory

> touch dir/filename / / create a filename file in the specified directory

> touch / home/zhangsan/dir/newfile / / create newfile files by absolute path

③ appends content to the file

> echo content > File / / add "content" to the file by overwriting

> echo content > > File / / add "content" to the file as "append"

(when using the above two instructions, the file does not exist and will be created automatically)

twelve。 User actions (create, modify, delete)

Corresponding configuration file: / etc/passwd

① creates useradd

> # useradd-g group code-d home directory-u user number user name

> # useradd user name

② modifies usermod

> # usermod-g group-d home directory (created manually)-u user number-l newname user name

③ Delete userdel

> # userdel-r user name / / Delete user information while deleting "Home Directory"

13. Actions of the group (create, modify, delete)

Corresponding configuration file: / etc/group

① creates groupadd

> # groupadd group name

② modifies groupmod

> # groupmod-g itself number-n new name group name

③ delete groupdel (Note: user information in the group is prohibited)

> # groupdel group

14. View the parameters that the instruction can use

> man instruction 15. Permission operation

1) set permissions by letter relative method

> chmod upright RWX filename Gmail RWX filename

Chmod upright, mummy Umurx filename

> chmod + wjimi filename

> chmod u+rx filename

> chmod g-wx filename

Groups can set one or more at a time

Specific permissions (rwx) can be set one or more at a time

+ /-increase and decrease permissions need to be set separately

Unified authority can be set for each group.

Ordinary users can only set permissions for files in their "home directory".

2) set permissions in digital absolute way

Read: 4

Write: 2

Execution: 1

0-> No permission

1-> execute permission

2-> write permission

3-> write and execute permissions

4-> read permission

5-> read and execute permissions

6-> read and write permissions

7-> read, write and execute permissions

> chmod ABC filename

ABC are three numbers that represent host, same group, and other group user rights.

Chmod 642 passwd

Master: read and write

Same group: read

Other: write

The choice between letters and numbers:

① permission modification [less] using alphabetical mode

② permission modification [more] using digital method

16. Search for content in a specified document

Content files searched for grep

All the information on the line of the searched content will be output.

> grep stap / etc/group searches for the word stap in group files

17. Find file lookup instruction

> find found catalog option value [option value]

Specific options:

-name file name / / find the file directly based on the file name

> find /-name passwd / / "recursively" traverse all the directories of the system, and search for passwd files

> find. /-name "o *" / / the name of the file that ambiguously looks for the o character as the starting content in the current directory

-size size / / find files directly based on file size

Unit: default 512 bytes

100c byte unit (size: 100cm 1)

12k kilobyte unit (size: 12kb 1024)

35 512 bytes (size: 35 '512)

5m megabytes (size: 5m 1024m 1024)

Range: + (greater than) /-(less than)

> find. /-size 23c / / find a file with a size of 23 bytes

> find. /-size + 7k / / find files with a size greater than 7k

> find. /-size-100c / / find a file with a size less than 100byte

-maxdepth hierarchy / / limits finding files at the deepest level

> find /-maxdepth 4-name passwd / / limit is up to 4 directory levels, and search for passwd files

-mindepth hierarchy / / limit the shallowest level to find files

-perm permission / / find files that match a certain permission

-user master name / / find the file through the host

-group group name / / find the file through the group

-type fhopper d / / look up according to "file / directory"

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