mkdir - make directory 创建目录
Usage：
Usage: mkdir [OPTION]... DIRECTORY...
Create the DIRECTORY(ies), if they do not already exist.
Mandatory arguments to long options are mandatory for short options too.
-m, --mode=MODE set file mode (as in chmod), not a=rwx - umask
-p, --parents no error if existing, make parent directories as needed
-v, --verbose print a message for each created directory
-Z set SELinux security context of each created directory
to the default type
--context[=CTX] like -Z, or if CTX is specified then set the SELinux
or SMACK security context to CTX
--help display this help and exit
--version output version information and exit
常用选项：
-m（mode）：按指定权限创建目录，若没有该选项则按 umask 的默认设置创建
-p（parent）：递归创建所有目录
-v（verbose）： 打印出每个创建的目录
- 递归创建目录
[root@78063f0fe2e8 ~]# mkdir -pv /tmp/test1/test2/test3
mkdir: created directory ‘/tmp/test1’
mkdir: created directory ‘/tmp/test1/test2’
mkdir: created directory ‘/tmp/test1/test2/test3’
- 目录的权限由 umask 决定
[root@78063f0fe2e8 ~]# umask
0022
[root@78063f0fe2e8 ~]# umask -S
u=rwx,g=rx,o=rx
[root@78063f0fe2e8 ~]# ls /tmp/test1 -l
total 4
drwxr-xr-x 3 root root 4096 Apr 21 05:01 test2
022是指对应三个组别分别要减去的权限分数，777-022=755=（rwxr-xr-x）
- 指定创建权限为711的目录
[root@78063f0fe2e8 ~]# mkdir /tmp/mingle -m 711
[root@78063f0fe2e8 ~]# ls /tmp/mingle -ld
drwx--x--x 2 root root 4096 Apr 21 05:10 /tmp/mingle
rmdir - remove empty directory 删除空目录
Usage：
Usage: rmdir [OPTION]... DIRECTORY...
Remove the DIRECTORY(ies), if they are empty.
--ignore-fail-on-non-empty
ignore each failure that is solely because a directory
is non-empty
-p, --parents remove DIRECTORY and its ancestors; e.g., 'rmdir -p a/b/c' is
similar to 'rmdir a/b/c a/b a'
-v, --verbose output a diagnostic for every directory processed
--help display this help and exit
--version output version information and exit
常用选项：
-p（parent）：递归删除空目录
-v（verbose）：打印出每个删除的目录
[root@78063f0fe2e8 ~]# mkdir -p /tmp/test1/test2/test3
[root@78063f0fe2e8 ~]# rmdir -pv /tmp/test1/test2/test3
rmdir: removing directory, ‘/tmp/test1/test2/test3’
rmdir: removing directory, ‘/tmp/test1/test2’
rmdir: removing directory, ‘/tmp/test1’
rmdir: removing directory, ‘/tmp’
rmdir: failed to remove directory ‘/tmp’: Directory not empty
pwd - print working directory 打印当前路径
Usage：
pwd [-LP]
常用选项：
-L（link）：若为软链，则显示软链路径(默认)
-P（）：若为软链，则显示为实际指向路径
[root@78063f0fe2e8 mail]# ls -ld /var/mail
lrwxrwxrwx 1 root root 10 Apr 2 18:38 /var/mail -> spool/mail
[root@78063f0fe2e8 mail]# pwd
/var/mail
[root@78063f0fe2e8 mail]# pwd -P
/var/spool/mail
[root@78063f0fe2e8 mail]# pwd -L
/var/mail
cd - change directory 切换当前路径
常用目录：
”.” ： 当前目录
”..” ：上级目录
”-” ：前一个工作目录
“~“,” “ ：当前用户所在的主目录 “~account” ：account 这个用户所在的主目录
[root@78063f0fe2e8 mail]# cd
[root@78063f0fe2e8 ~]#
[root@78063f0fe2e8 ~]# cd /tmp
[root@78063f0fe2e8 tmp]# cd
[root@78063f0fe2e8 ~]# cd ~root
[root@78063f0fe2e8 ~]# cd -
/root
[root@78063f0fe2e8 ~]# cd ..
[root@78063f0fe2e8 /]# cd -
/root
[root@78063f0fe2e8 ~]# cd /var/mail
[root@78063f0fe2e8 mail]#