ls
ls -l
(I recommend ls -lh where you can see the size)
┌─[root@nedrain]─[/]
└──? $ls -l
total 60
lrwxrwxrwx. 1 root root 7 Oct 15 2017 bin -> usr/bin
dr-xr-xr-x. 5 root root 4096 Oct 15 2017 boot
drwxr-xr-x 19 root root 2960 Jun 16 10:51 dev
drwxr-xr-x. 79 root root 4096 Jun 16 11:35 etc
drwxr-xr-x. 2 root root 4096 Nov 5 2016 home
lrwxrwxrwx. 1 root root 7 Oct 15 2017 lib -> usr/lib
lrwxrwxrwx. 1 root root 9 Oct 15 2017 lib64 -> usr/lib64
drwx------. 2 root root 16384 Oct 15 2017 lost+found
drwxr-xr-x. 2 root root 4096 Nov 5 2016 media
drwxr-xr-x. 2 root root 4096 Nov 5 2016 mnt
drwxr-xr-x. 2 root root 4096 Nov 5 2016 opt
dr-xr-xr-x 82 root root 0 Jun 16 10:51 proc
dr-xr-x---. 5 root root 4096 Jun 16 13:28 root
drwxr-xr-x 22 root root 620 Jun 16 10:51 run
lrwxrwxrwx. 1 root root 8 Oct 15 2017 sbin -> usr/sbin
drwxr-xr-x. 2 root root 4096 Nov 5 2016 srv
dr-xr-xr-x 13 root root 0 Jun 16 2020 sys
drwxrwxrwt. 9 root root 4096 Jun 16 12:08 tmp
drwxr-xr-x. 13 root root 4096 Oct 15 2017 usr
drwxr-xr-x. 19 root root 4096 Oct 15 2017 var
ls -i ( show the inode)
┌─[root@nedrain]─[/boot]
└──? $ls -i
1182233 config-3.10.0-693.2.2.el7.x86_64
1181811 config-3.10.0-693.el7.x86_64
1179651 efi
1181552 grub
1179654 grub2
1181920 initramfs-0-rescue-f0f31005fb5a436d88e3c6cbf54e25aa.img
1182237 initramfs-3.10.0-693.2.2.el7.x86_64.img
1181919 initramfs-3.10.0-693.el7.x86_64.img
1181917 initramfs-3.10.0-693.el7.x86_64kdump.img
1181918 initrd-plymouth.img
1182234 symvers-3.10.0-693.2.2.el7.x86_64.gz
1181812 symvers-3.10.0-693.el7.x86_64.gz
1182232 System.map-3.10.0-693.2.2.el7.x86_64
1181810 System.map-3.10.0-693.el7.x86_64
1181921 vmlinuz-0-rescue-f0f31005fb5a436d88e3c6cbf54e25aa
1182235 vmlinuz-3.10.0-693.2.2.el7.x86_64
1181813 vmlinuz-3.10.0-693.el7.x86_64
mkdir -p 123/456/789
make directory recursively ** watch out it‘s p not r**
┌─[root@nedrain]─[~]
└──? $mkdir -p 123/456/789
┌─[root@nedrain]─[~]
└──? $ls
123
┌─[root@nedrain]─[~]
└──? $ls 123
456
┌─[root@nedrain]─[~]
└──? $ls 123/456
789