从头开始积累centos7系统运用
大牛博客：https://blog.51cto.com/yangrong/p5
1.查看命令帮助的方法：
--help 适用于一般命令，非内置命令
man 适用于一般命令，非内置命令
help 适用内置命令：
info 了解即可
2.pwd 当前工作目录：
[root@python01 ~]# cd /etc/init.d/
快捷方式 逻辑路径
[root@python01 init.d]# pwd -L
/etc/init.d
P显示源文件的初始目录： 物理路径
[root@python01 init.d]# pwd -P
/etc/rc.d/init.d
[root@python01 init.d]# ls -l /etc/init.d
lrwxrwxrwx. 1 root root 11 May 24 23:24 /etc/init.d -> rc.d/init.d
3.mkdir
创建目录： -p 参数批量创建目录
4.echo
echo 1 2 3 4 5
[root@python01 ~]# echo {1..10}
1 2 3 4 5 6 7 8 9 10
[root@python01 test]# mkdir dir{1..5}
[root@python01 test]# tree
.
├── dir1
├── dir2
├── dir3
├── dir4
└── dir5
5 directories, 0 files
[root@python01 test]# echo {1..3}{4..6}
14 15 16 24 25 26 34 35 36
[root@python01 test]# mkdir dir{1..3}{4..6}
[root@python01 test]# tree
.
├── dir1
├── dir14
├── dir15
├── dir16
├── dir2
├── dir24
├── dir25
├── dir26
├── dir3
├── dir34
├── dir35
├── dir36
├── dir4
└── dir5
14 directories, 0 files
-pv查看创建过程 创建测试目录，创建多级子目录
[root@python01 test]# mkdir -pv dirls/{1..3}/{4..6}
mkdir: created directory ‘dirls’
mkdir: created directory ‘dirls/1’
mkdir: created directory ‘dirls/1/4’
mkdir: created directory ‘dirls/1/5’
mkdir: created directory ‘dirls/1/6’
mkdir: created directory ‘dirls/2’
mkdir: created directory ‘dirls/2/4’
mkdir: created directory ‘dirls/2/5’
mkdir: created directory ‘dirls/2/6’
mkdir: created directory ‘dirls/3’
mkdir: created directory ‘dirls/3/4’
mkdir: created directory ‘dirls/3/5’
mkdir: created directory ‘dirls/3/6’
4.cd 命令 内置命令
切换改变目录
路径：
相对路径：不从/根开始 test/a/b
绝对路径：从/根开始 /root/test/a/b
-a 参数显示隐藏目录：
. 当前目录
.. 上级目录
- 上一次目录
[root@python01 test]# ls
dir1 dir115 dir124 dir126 dir135 dir14 dir16 dir24 dir26 dir34 dir36 dir5
dir114 dir116 dir125 dir134 dir136 dir15 dir2 dir25 dir3 dir35 dir4 dirls
[root@python01 test]# ls -a
. dir1 dir115 dir124 dir126 dir135 dir14 dir16 dir24 dir26 dir34 dir36 dir5
.. dir114 dir116 dir125 dir134 dir136 dir15 dir2 dir25 dir3 dir35 dir4 dirls
pwd
[root@python01 etc]# echo $OLDPWD
/root/test
-
[root@python01 etc]# echo $PWD
/etc
~ 家目录home 目录
5.tree命令：
yun -y install tree
tree - list contents of directories in a tree-like format.
-L 指定显示的层级：
[root@python01 ~]# tree -L 1
.
├── anaconda-ks.cfg
├── epel-release-latest-7.noarch.rpm
└── test
- d 参数只看目录
[root@python01 ~]# tree test -dL 1
test
├── dir1
├── dir114
├── dir115
├── dir116
├── dir124
├── dir125
├── dir126
├── dir134
├── dir135
├── dir136
├── dir14
├── dir15
├── dir16
├── dir2
├── dir24
├── dir25
├── dir26
├── dir3
├── dir34
├── dir35
├── dir36
├── dir4
├── dir5
└── dirls
-f 参数 显示完整的目录结构
[root@python01 ~]# tree test -dLf 1
test
├── test/dir1
├── test/dir114
├── test/dir115
├── test/dir116
├── test/dir124
├── test/dir125
├── test/dir126
├── test/dir134
├── test/dir135
├── test/dir136
├── test/dir14
├── test/dir15
├── test/dir16
├── test/dir2
├── test/dir24
├── test/dir25
├── test/dir26
├── test/dir3
├── test/dir34
├── test/dir35
├── test/dir36
├── test/dir4
├── test/dir5
└── test/dirls
-i 参数 去掉连接的树枝保留文件目录
-i Don't print indentation lines.
[root@python01 ~]# tree -dLfi 2
.
./test
./test/dir1
./test/dir114
./test/dir115
./test/dir116
./test/dir124
./test/dir125
./test/dir126
./test/dir134
./test/dir135
./test/dir136
./test/dir14
./test/dir15
./test/dir16
./test/dir2
./test/dir24
./test/dir25
./test/dir26
./test/dir3
./test/dir34
./test/dir35
./test/dir36
./test/dir4
./test/dir5
./test/dirls
6.touch 命令：
创建新文件
[root@python01 test]# touch oldboy.txt
[root@python01 test]# touch a.txt b.txt
[root@python01 test]# touch {c..f}.txt
更改就文件的时间戳
[root@python01 test]# stat oldboy.txt
File: ‘oldboy.txt’
Size: 0 Blocks: 0 IO Block: 4096 regular empty file
Device: fd00h/64768d Inode: 33575412 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)
Access: 2019-06-18 10:49:11.398749245 +0800
Modify: 2019-06-18 10:49:11.398749245 +0800
Change: 2019-06-18 10:49:11.398749245 +0800
Birth: -
- a 代表创建时间
[root@python01 test]# touch -a oldboy.txt
[root@python01 test]# stat oldboy.txt
File: ‘oldboy.txt’
Size: 0 Blocks: 0 IO Block: 4096 regular empty file
Device: fd00h/64768d Inode: 33575412 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)
Access: 2019-06-18 11:04:43.335778923 +0800
Modify: 2019-06-18 10:49:11.398749245 +0800
Change: 2019-06-18 11:04:43.335778923 +0800
Birth: -
- m 代表修改时间
[root@python01 test]# touch -m oldboy.txt
[root@python01 test]# stat oldboy.txt
File: ‘oldboy.txt’
Size: 0 Blocks: 0 IO Block: 4096 regular empty file
Device: fd00h/64768d Inode: 33575412 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)
Access: 2019-06-18 11:04:43.335778923 +0800
Modify: 2019-06-18 11:12:23.581793580 +0800
Change: 2019-06-18 11:12:23.581793580 +0800
Birth: -
关机的命令
shutdown -h now
halt
重启电脑的命令：
reboot
shutdown -r
shutdown --help
-r --reboot Reboot the machine
-h Equivalent to --poweroff, overridden by --halt
history 命令：属于22系统优化的内容
history历史命令记录
配合感叹号使用调取历史命令：
154 touch 谢国成.txt
155 ls
156 rm -f 谢国成.txt
157 ls
158 setup
159 history
[root@python01 ~]# !155
ls
anaconda-ks.cfg epel-release-latest-7.noarch.rpm test
清空历史命令：
清空所有
history -c
保留5条历史命令记录
history -d -5
特殊变量：控制命令历史输出记录数量
export HISTSIZE=5
[root@python01 ~]# export HISTSIZE=5
[root@python01 ~]# history
158 history
159 ls
160 export HISTFILESIZE=5
161 export HISTSIZE=5
162 history
export HISTFILESIZE=5
[root@python01 ~]# cat ~/.bash_history
runlever
runlevel
systemctl get-default
shutdown --help
systemctl status firewalld.service
free -m 查看内存命令
[root@python01 ~]# free -m
total used free shared buff/cache available
Mem: 3771 84 3380 11 306 3431