table of Contents
- Linux basic commands comments (2)
- ln link file
- copy copy a file, a file to a file, multiple files to a directory
- cat and tac
- more full-screen view text automatically exit the front (after the space turning) back after reading
- less: full-screen view after page text box, b front page, reading does not automatically quit, q quit
- head 与tail
- du view files or directories take up disk space
- df report file system disk space usage
- hostname modify the hostname
- who
- which view commands absolute path
- clear clear screen
- cal Calendar Print
- ldd command to view those dependent libraries
- date time
- help
Linux basic commands comments (2)
ln link file
- ln -s [source] [link name] soft connection
[root@localhost ~]# ln -s anaconda-ks.cfg acd
[root@localhost ~]# ls -l
总用量 20
drwxr-xr-x. 3 root root 37 9月 8 11:02 a
-rw-r--r--. 1 root root 21 9月 8 09:31 abc
lrwxrwxrwx. 1 root root 15 9月 10 09:46 acd -> anaconda-ks.cfg
-rw-------. 1 root root 1451 9月 6 22:57 anaconda-ks.cfg
- ln [source] [connection name] hard links
[root@localhost ~]# ln anaconda-ks.cfg vbn
[root@localhost ~]# ll
总用量 24
drwxr-xr-x. 3 root root 37 9月 8 11:02 a
-rw-r--r--. 1 root root 21 9月 8 09:31 abc
lrwxrwxrwx. 1 root root 15 9月 10 09:46 acd -> anaconda-ks.cfg
-rw-------. 2 root root 1451 9月 6 22:57 anaconda-ks.cfg
-rw-r--r--. 1 root root 0 9月 7 15:56 bbb
drwxr-xr-x. 3 root root 15 9月 7 16:33 c
-rw-r--r--. 1 root root 327 9月 7 16:42 cc
-rw-r--r--. 1 root root 126 9月 7 15:53 qwq
-rw-------. 2 root root 1451 9月 6 22:57 vbncopy copy a file, a file to a file, multiple files to a directory
- cp
[root@localhost ~]# ls
a abc acd anaconda-ks.cfg bbb c cc qwq vbn wqw
[root@localhost ~]# cp abc cc
cp：是否覆盖"cc"？ y- -a archive copy, commonly used in backup
[root@localhost ~]# ls
a abc acd anaconda-ks.cfg bbb c cc qwq vbn wqw
[root@localhost ~]# cp -a abc acb
[root@localhost ~]# ls
a abc acb acd anaconda-ks.cfg bbb c cc qwq vbn wqw- -r recursive copy, you must use this option when copying directories
[root@localhost ~]# ls
a abc acb acd anaconda-ks.cfg bbb c cc qwq vbn wqw
[root@localhost ~]# ls c
[root@localhost ~]#
[root@localhost ~]# cp -r a c
cat and tac
- cat stitching contents of the file and output to the standard output (screen)
[root@localhost ~]# cat qwq
rootpw --iscrypted $6$15KaJSMJ1CnXnZP6$i.4EoTpZwTUTcZhK0oYRIjgyP9UTYbXsq//IV4xIiaB.2RfwtJP7SzhiAN4KcrAZP1ABjRIPx9pdl7vXdHoJk.
[root@localhost ~]# cat qwq wqw
rootpw --iscrypted $6$15KaJSMJ1CnXnZP6$i.4EoTpZwTUTcZhK0oYRIjgyP9UTYbXsq//IV4xIiaB.2RfwtJP7SzhiAN4KcrAZP1ABjRIPx9pdl7vXdHoJk.
rootpw --iscrypted $6$15KaJSMJ1CnXnZP6$i.4EoTpZwTUTcZhK0oYRIjgyP9UTYbXsq//IV4xIiaB.2RfwtJP7SzhiAN4KcrAZP1ABjRIPx9pdl7vXdHoJk.
pwpolicy root --minlen=6 --minquality=1 --notstrict --nochanges --notempty- -n number of display lines
[root@localhost ~]# cat -n anaconda-ks.cfg
1 #version=DEVEL
2 # System authorization information
3 auth --enableshadow --passalgo=sha512
4 repo --name="Server-HighAvailability" --baseurl=file:///run/install/repo/addons/HighAvailability
5 repo --name="Server-ResilientStorage" --baseurl=file:///run/install/repo/addons/ResilientStorage
6 # Use CDROM installation media
7 cdrom
8 # Use graphical install
9 graphical
10 # Run the Setup Agent on first boot
11 firstboot --enable
12 ignoredisk --only-use=sda
13 # Keyboard layouts
14 keyboard --vckeymap=cn --xlayouts='cn'
15 # System language
16 lang zh_CN.UTF-8
.....
- tac reverse link file and print content to standard output
[root@localhost ~]# cat /etc/issue
\S
Kernel \r on an \m
[root@localhost ~]# tac /etc/issue
Kernel \r on an \m
\Smore full-screen view text automatically exit the front (after the space turning) back after reading
[root@localhost ~]# more anaconda-ks.cfg
#version=DEVEL
# System authorization information
auth --enableshadow --passalgo=sha512
repo --name="Server-HighAvailability" --baseurl=file:///run/install/repo/addons/HighAvaila
bility
repo --name="Server-ResilientStorage" --baseurl=file:///run/install/repo/addons/ResilientS
torage
# Use CDROM installation media
cdrom
# Use graphical install
graphical
# Run the Setup Agent on first boot
firstboot --enable
ignoredisk --only-use=sda
# Keyboard layouts
keyboard --vckeymap=cn --xlayouts='cn'
# System language
lang zh_CN.UTF-8
...less: full-screen view after page text box, b front page, reading does not automatically quit, q quit
[root@localhost ~]# less anaconda-ks.cfg head 与tail
- print head from the file header of the file content, the default 10 lines
[root@localhost ~]# head anaconda-ks.cfg
#version=DEVEL
# System authorization information
auth --enableshadow --passalgo=sha512
repo --name="Server-HighAvailability" --baseurl=file:///run/install/repo/addons/HighAvailability
repo --name="Server-ResilientStorage" --baseurl=file:///run/install/repo/addons/ResilientStorage
# Use CDROM installation media
cdrom
# Use graphical install
graphical
# Run the Setup Agent on first boot- [n] n display lines
[root@localhost ~]# head -15 anaconda-ks.cfg
#version=DEVEL
# System authorization information
auth --enableshadow --passalgo=sha512
repo --name="Server-HighAvailability" --baseurl=file:///run/install/repo/addons/HighAvailability
repo --name="Server-ResilientStorage" --baseurl=file:///run/install/repo/addons/ResilientStorage
# Use CDROM installation media
cdrom
# Use graphical install
graphical
# Run the Setup Agent on first boot
firstboot --enable
ignoredisk --only-use=sda
# Keyboard layouts
keyboard --vckeymap=cn --xlayouts='cn'
# System language[root@localhost ~]# cat anaconda-ks.cfg |head -15
#version=DEVEL
# System authorization information
auth --enableshadow --passalgo=sha512
repo --name="Server-HighAvailability" --baseurl=file:///run/install/repo/addons/HighAvailability
repo --name="Server-ResilientStorage" --baseurl=file:///run/install/repo/addons/ResilientStorage
# Use CDROM installation media
cdrom
# Use graphical install
graphical
# Run the Setup Agent on first boot
firstboot --enable
ignoredisk --only-use=sda
# Keyboard layouts
keyboard --vckeymap=cn --xlayouts='cn'
# System language- From the tail end of the file to print the contents of a file, the default 10 lines
[root@localhost ~]# tail anaconda-ks.cfg
%addon com_redhat_kdump --enable --reserve-mb='auto'
%end
%anaconda
pwpolicy root --minlen=6 --minquality=1 --notstrict --nochanges --notempty
pwpolicy user --minlen=6 --minquality=1 --notstrict --nochanges --emptyok
pwpolicy luks --minlen=6 --minquality=1 --notstrict --nochanges --notempty
%end
- [n] n display lines
[root@localhost ~]# tail -15 anaconda-ks.cfg
@core
chrony
kexec-tools
%end
%addon com_redhat_kdump --enable --reserve-mb='auto'
%end
%anaconda
pwpolicy root --minlen=6 --minquality=1 --notstrict --nochanges --notempty
pwpolicy user --minlen=6 --minquality=1 --notstrict --nochanges --emptyok
pwpolicy luks --minlen=6 --minquality=1 --notstrict --nochanges --notempty
%end
[root@localhost ~]# cat anaconda-ks.cfg |tail -15
@core
chrony
kexec-tools
%end
%addon com_redhat_kdump --enable --reserve-mb='auto'
%end
%anaconda
pwpolicy root --minlen=6 --minquality=1 --notstrict --nochanges --notempty
pwpolicy user --minlen=6 --minquality=1 --notstrict --nochanges --emptyok
pwpolicy luks --minlen=6 --minquality=1 --notstrict --nochanges --notempty
%end
- Displays [n] lines
[root@localhost ~]# cat anaconda-ks.cfg |head -11 | tail -1
firstboot --enable
[root@localhost ~]# head -11 anaconda-ks.cfg | tail -1
firstboot --enabledu view files or directories take up disk space
- du view files or directories take up disk space
[root@localhost ~]# du a
0 a/c
4 a- -s only view the catalog
[root@localhost ~]# du -s a
4 a- -h display the directory file size
[root@localhost ~]# du -sh a
4.0K a- wc text statistics; -c: count the number of text bytes; w: count the number of words of text; -l: Number of lines of text l Statistics
[root@localhost ~]# wc abc
3 3 21 abc
[root@localhost ~]# wc -c abc
21 abc
[root@localhost ~]# wc -w abc
3 abc
[root@localhost ~]# wc -l abc
3 abcdf report file system disk space usage
- df report file system disk space usage
[root@localhost ~]# df
文件系统 1K-块 已用 可用 已用% 挂载点
/dev/mapper/rhel-root 40137576 971488 39166088 3% /
devtmpfs 922456 0 922456 0% /dev
tmpfs 933524 0 933524 0% /dev/shm
tmpfs 933524 8844 924680 1% /run
tmpfs 933524 0 933524 0% /sys/fs/cgroup
/dev/sda1 1038336 145824 892512 15% /boot
/dev/mapper/rhel-home 19593216 32956 19560260 1% /home
tmpfs 186708 0 186708 0% /run/user/0- -h: unit conversion, display size in a more friendly way
[root@localhost ~]# df -h
文件系统 容量 已用 可用 已用% 挂载点
/dev/mapper/rhel-root 39G 949M 38G 3% /
devtmpfs 901M 0 901M 0% /dev
tmpfs 912M 0 912M 0% /dev/shm
tmpfs 912M 8.7M 904M 1% /run
tmpfs 912M 0 912M 0% /sys/fs/cgroup
/dev/sda1 1014M 143M 872M 15% /boot
/dev/mapper/rhel-home 19G 33M 19G 1% /home
tmpfs 183M 0 183M 0% /run/user/0hostname modify the hostname
- hostname view or modify temporary host name, reopen the terminal is valid, failure to restart
[root@hostnamectl ~]# hostname
hostnamectl
[root@hostnamectl ~]# hostname M
[root@hostnamectl ~]# hostname
M- hostnmectl modify the host name (will modify the configuration file), the reopening of the terminal effective, restart is still valid
[root@M ~]# hostnamectl set-hostname hostnamectl
[root@M ~]# hostname
hostnamectl
[root@M ~]# shutdown -r now
Last login: Tue Sep 10 13:00:46 2019 from 192.168.213.1
[root@hostnamectl ~]#
who
[root@hostnamectl ~]# who //显示当前登录用户
root pts/0 2019-09-10 13:02 (192.168.213.1)
[root@hostnamectl ~]# w //显示当前在线用户并显示其正在运行的命令
13:06:14 up 3 min, 1 user, load average: 0.01, 0.01, 0.01
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
root pts/0 192.168.213.1 13:02 6.00s 0.07s 0.06s w
[root@hostnamectl ~]# whoami //显示当前登录用户
root
[root@hostnamectl ~]# who am i //显示当前登录用户
root pts/0 2019-09-10 13:02 (192.168.213.1)
[root@hostnamectl ~]# - Check your tty terminal
[root@hostnamectl ~]# tty
/dev/pts/0which view commands absolute path
[root@hostnamectl ~]# which ls
alias ls='ls --color=auto'
/usr/bin/lsclear clear screen
- clear or Ctrl + l
[root@hostnamectl ~]# clear
[root@hostnamectl ~]# cal Calendar Print
[root@hostnamectl ~]# cal
九月 2019
日 一 二 三 四 五 六
1 2 3 4 5 6 7
8 9 10 11 12 13 14
15 16 17 18 19 20 21
22 23 24 25 26 27 28
29 30- [N] output of the calendar year n 1 to 9999
[root@hostnamectl ~]# cal 2012
2012
一月 二月 三月
日 一 二 三 四 五 六 日 一 二 三 四 五 六 日 一 二 三 四 五 六
1 2 3 4 5 6 7 1 2 3 4 1 2 3
8 9 10 11 12 13 14 5 6 7 8 9 10 11 4 5 6 7 8 9 10
15 16 17 18 19 20 21 12 13 14 15 16 17 18 11 12 13 14 15 16 17
22 23 24 25 26 27 28 19 20 21 22 23 24 25 18 19 20 21 22 23 24
29 30 31 26 27 28 29 25 26 27 28 29 30 31
四月 五月 六月
日 一 二 三 四 五 六 日 一 二 三 四 五 六 日 一 二 三 四 五 六
1 2 3 4 5 6 7 1 2 3 4 5 1 2
8 9 10 11 12 13 14 6 7 8 9 10 11 12 3 4 5 6 7 8 9
15 16 17 18 19 20 21 13 14 15 16 17 18 19 10 11 12 13 14 15 16
22 23 24 25 26 27 28 20 21 22 23 24 25 26 17 18 19 20 21 22 23
29 30 27 28 29 30 31 24 25 26 27 28 29 30
七月 八月 九月
日 一 二 三 四 五 六 日 一 二 三 四 五 六 日 一 二 三 四 五 六
1 2 3 4 5 6 7 1 2 3 4 1
8 9 10 11 12 13 14 5 6 7 8 9 10 11 2 3 4 5 6 7 8
15 16 17 18 19 20 21 12 13 14 15 16 17 18 9 10 11 12 13 14 15
22 23 24 25 26 27 28 19 20 21 22 23 24 25 16 17 18 19 20 21 22
29 30 31 26 27 28 29 30 31 23 24 25 26 27 28 29
30
十月 十一月 十二月
日 一 二 三 四 五 六 日 一 二 三 四 五 六 日 一 二 三 四 五 六
1 2 3 4 5 6 1 2 3 1
7 8 9 10 11 12 13 4 5 6 7 8 9 10 2 3 4 5 6 7 8
14 15 16 17 18 19 20 11 12 13 14 15 16 17 9 10 11 12 13 14 15
21 22 23 24 25 26 27 18 19 20 21 22 23 24 16 17 18 19 20 21 22
28 29 30 31 25 26 27 28 29 30 23 24 25 26 27 28 29
30 31
ldd command to view those dependent libraries
[root@hostnamectl ~]# ldd /usr/bin/ls
linux-vdso.so.1 => (0x00007ffe917ec000)
libselinux.so.1 => /lib64/libselinux.so.1 (0x00007f3a56334000)
libcap.so.2 => /lib64/libcap.so.2 (0x00007f3a5612f000)
libacl.so.1 => /lib64/libacl.so.1 (0x00007f3a55f25000)
libc.so.6 => /lib64/libc.so.6 (0x00007f3a55b62000)
libpcre.so.1 => /lib64/libpcre.so.1 (0x00007f3a55900000)
libdl.so.2 => /lib64/libdl.so.2 (0x00007f3a556fb000)
/lib64/ld-linux-x86-64.so.2 (0x00005561b7879000)
libattr.so.1 => /lib64/libattr.so.1 (0x00007f3a554f6000)
libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f3a552da000)
date time
[root@hostnamectl ~]# date
2019年 09月 10日 星期二 13:21:59 CST[root@hostnamectl ~]# date -s '2019-09-10 13:21:30'
2019年 09月 10日 星期二 13:21:30 CST- Formatting Output Time:
+% the Y: Year
+% m: month
+% d: Day
+% H: When
+% M: fraction
+% S: seconds
[root@hostnamectl ~]# date +%y
19
[root@hostnamectl ~]# date +%m
09
[root@hostnamectl ~]# date +%d
10
[root@hostnamectl ~]# date +%H
13
[root@hostnamectl ~]# date +%M
56
[root@hostnamectl ~]# date +%MS- Current file creation time
[root@hostnamectl ~]# touch $(date '+%Y%m%d')
[root@hostnamectl ~]# ls
20190910 a abc acb acd anaconda-ks.cfg bbb help
- help command built-in command
[root@hostnamectl ~]# help cd
cd: cd [-L|[-P [-e]]] [dir]
Change the shell working directory.
Change the current directory to DIR. The default DIR is the value of the
HOME shell variable.
The variable CDPATH defines the search path for the directory containing
DIR. Alternative directory names in CDPATH are separated by a colon (:).
A null directory name is the same as the current directory. If DIR begins
with a slash (/), then CDPATH is not used.
If the directory is not found, and the shell option `cdable_vars' is set,
the word is assumed to be a variable name. If that variable has a value,
its value is used for DIR.- CMMAND --help external command
[root@hostnamectl ~]# ls --help
用法：ls [选项]... [文件]...
List information about the FILEs (the current directory by default).
Sort entries alphabetically if none of -cftuvSUX nor --sort is specified.
Mandatory arguments to long options are mandatory for short options too.
-a, --all 不隐藏任何以. 开始的项目
-A, --almost-all 列出除. 及.. 以外的任何项目
--author 与-l 同时使用时列出每个文件的作者
-b, --escape 以八进制溢出序列表示不可打印的字符
--block-size=SIZE scale sizes by SIZE before printing them; e.g.,
'--block-size=M' prints sizes in units of
1,048,576 bytes; see SIZE format below
-B, --ignore-backups do not list implied entries ending with ~
-c with -lt: sort by, and show, ctime (time of last
modification of fil- man manual
[]: Optional
<>: Required
...: there may be many times
|: A multiple-choice
{}: Packet
NAME: command name and a brief description of the function
SYNOPSIS: Usage Notes, including the options available
DESCRIPTION: detailed description of the command function, and may include the meaning of each option
OPTIONS: explain the significance of each option
FILES: This command related configuration files
BUGS: report a bug
EXAMPLES: Example command
SEE ALSO: additional reference
Scroll: space (turned back one screen), b key (flip ahead a screen)
Find:
/ KEYWORD: front to back to find KEYWORD
KEYWORD:? From the look KEYWORD forward
n: the next matching row
row before a match: N
q: quit
man
Find on a capital N
Lowercase n Find Next
Mandatory arguments to long options are mandatory for short options too.
-a, --all
do not ignore entries starting with .
-A, --almost-all
do not list implied . and ..
--author
with -l, print the author of each file
-b, --escape
print C-style escapes for nongraphic characters
--block-size=SIZE
scale sizes by SIZE before printing them; e.g., '--block-size=M' prints
sizes in units of 1,048,576 bytes; see SIZE format below
-B, --ignore-backups
do not list implied entries ending with ~
-c with -lt: sort by, and show, ctime (time of last modification of file
status information); with -l: show ctime and sort by name; otherwise:
sort by ctime, newest first
-C list entries by columns
Manual page ls(1) line 15 (press h for help or q to quit)