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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