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File Management Commands

Ls-l

The first column is the file type

-: Normal file

C: Character file

L: Link

P: Pipeline File

B: Block device

Ls-m

Comma separated

[Email protected] ~]# ls-m/var/

ADM, cache, crash, db, empty, games, Gopher, Kerberos, LIB, local, lock, log, mail, NIS, opt, preserve, run, spool,

TMP, VAR, YP

LS--time=atime

Access time

--time=ctime

Modification time

--full-time

Detailed Access time

[[email protected] ~]# ls--full-time

Total 16

-RW-------. 1 root root 1163 2017-10-23 22:53:42.398974266 +0800 anaconda-ks.cfg

-rw-r--r--. 1 root root 2017-09-09 12:34:08.001916663 +0800 a.txt

-rw-r--r--. 1 root root 2017-09-09 12:34:27.883915853 +0800 b.txt

Drwxr-xr-x. 2 root root 4096 2017-10-23 23:05:44.724975372 +0800 initial_repo_backup

[Email protected] ~]#

-R

List all subdirectory tiers at the same time

-H

Output the list file size in human format

--sort time

Sort by Time

--sort size

Sort by size

RmDir

Delete Empty Directory

Rmdir-p

Delete a multilevel empty directory

Additions and deletions except users

Useradd User Name

passwd User Name

Add Password to User

Userdel User Name

Delete User

-R Delete Home directory

Date

-R,--rfc-2822

Output date and time in RFC 2822 format. Example:mon, 2006 12:34:56-0600

-U

UTC (Universal time coordinated)

Same as the GMT meaning

CST is our own standard time.

Date [+format]

[Email protected] ~]# date +%c

Mon-Oct 05:37:33 PM EDT

[Email protected] ~]#

%s calculates the current elapsed time, starting January 1, 1970 0:0

%j show the day of the year%M minutes (00-59)

[Email protected] ~]# date +%d

10/24/17

[Email protected] ~]# date +%a

Tuesday

[Email protected] ~]# date +%h

14

[Email protected] ~]# date +%h%d

1410/24/17

[Email protected] ~]#

Example: 1. View August 15, 1945 is the day of the week (the current time is 2017-10-24)

[[email protected] ~]# date-d " -72 year-2 month-9 Days"

Wed 15:01:16 CST 1945

[Email protected] ~]#

2. View August 15, 2045 is the day of the week (the current time is 2017-10-24)

[[email protected] ~]# date-d "+28 years-2 months-9 Days"

Tue 15:30:11 CST 2045

[Email protected] ~]#

Hwclock Hardware Clock

Hwclock-w SYSTOHC

Hwclock-s Hctosys

Tzselect Time zone selection

[Email protected] ~]# Tzselect

Please identify a, so, time zone rules can be set correctly.

Please select a continent or ocean.

1) Africa

2) Americas

3) Antarctica

4) Arctic Ocean

5) Asia

6) Atlantic Ocean

7) Australia

8) Europe

9) Indian Ocean

Pacific Ocean

One) None-i want to specify the time zone using the Posix TZ format.

#?

Timedatectl Show The time

[Email protected] ~]# Timedatectl

Local time:tue 2017-10-24 15:36:43 CST

Universal time:tue 2017-10-24 07:36:43 UTC

RTC Time:tue 2017-10-24 07:36:43

TIMEZONE:N/A (CST, +0800)

NTP enabled:n/a

NTP Synchronized:no

RTC in local Tz:no

DST active:n/a

[Email protected] ~]#

Display the time zones supported by the system

[Email protected] ~]# Timedatectl List-timezones | More

Africa/abidjan

Africa/accra

Africa/addis_ababa

Africa/algiers

........

Set the current time zone

[Email protected] ~]# Timedatectl set-timezone Asia/shanghai

[Email protected] ~]#

Set Current system time

[[email protected] ~]# timedatectl set-time "2017-9-9 12:00:00"

[[Email protected] ~]# Date

Sat Sep 9 12:00:01 CST 2017

[Email protected] ~]#

Sets whether NTP time synchronization is turned on (provided the NTP server is turned on)

[[email protected] ~]# Timedatectl set-ntp True

Cat [Options] File name

-B Displays the number of rows when displaying the contents of a file

-N Display file contents including blank lines

-S merges multiple empty rows into one empty row output

More [options] file name

+ lines are displayed directly starting with the given number of rows

-S compresses multiple empty rows into a blank line

-p clear the screen and then display

Head [options] File

-N < rows > Displays the first specified line of the file

-C < bytes > Displays the contents of the first n bytes of a file

-Q does not output the contents of the file header

-V Output File header contents

[Email protected] ~]# head-10-v/etc/fstab

==>/etc/fstab <==

#

#/etc/fstab

# Created by Anaconda on Mon Oct 23 14:49:30 2017

#

# Accessible filesystems, by reference, is maintained under '/dev/disk '

# See mans Pages Fstab (5), Findfs (8), mount (8) and/or Blkid (8) for more info

#

UUID=DEBEB2CD-B005-4C53-87E9-8F78A4A33C00/EXT3 Defaults 1 1

Uuid=732a5dec-be83-4581-bba0-29395eed3552/boot XFS Defaults 0 0

[Email protected] ~]#

tail [options] File

-F Loop Read

-C < bytes > Displays the contents of the first n bytes of a file

-Q does not output the contents of the file header

-N < rows > Specify the number of rows displayed

-V Output File header contents

diff [Options] file1 file2

Display information:

A is required for additional

D is required to delete

C for need to modify

[Email protected] ~]# diff a.txt B.txt

4d3

< D

7c6

< This is what we want

---

> know that ' s tough

[email protected] ~]# cat A.txt

A

B

C

D

1

2

This is the what we want

[email protected] ~]# cat B.txt

A

B

C

1

2

You know that ' s tough

[Email protected] ~]#

MV [Options] source file destination Path

-I prompt if the destination has the same file name

-V Show Progress when moving files, move multiple files

Very useful when

-U when moving only when the source file is newer than the destination file

Before it moves.

-F Force Overwrite existing files

CP [Options] File name (original) destination file name (copy)

-r Copy the contents of the entire directory

The permission value of the directory is retained after-p copy finishes

-V Show Progress when copying files

-F at the time of copying, if you encounter the destination file name is duplicated, the original deleted

RM [Options] File name

-I need to manually confirm before deleting a file

-V Displays information when deleting files

-R Delete directory-F ignore prompt

Example: rm-v filename

Common options: RM-RF directory Name

ln [options] source file Link file

-F Delete A destination file that already exists

-I if I encounter a hint with duplicate name how to operate

-V Display Operation information

-S Soft link option

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