创建一个 foo.txt 文件
$ touch foo.txt
$ echo "hello" > foo.txt
$ cat foo.txt
hello
foo.txt 文件的 inode 是 13
$ ls -lhi foo.txt
13 -rw-rw-r-- 1 huangjian huangjian 6 Feb 22 13:56 foo.txt
$ stat foo.txt
File: 'foo.txt'
Size: 6 Blocks: 8 IO Block: 4096 regular file
Device: 800h/2048d Inode: 13 Links: 1
Access: (0664/-rw-rw-r--) Uid: ( 1000/huangjian) Gid: ( 1000/huangjian)
Access: 2019-02-22 13:56:35.097721182 +0800
Modify: 2019-02-22 13:56:31.645684665 +0800
Change: 2019-02-22 13:56:31.645684665 +0800
Birth: -
cp 拷贝出来的文件，inode 的值改变了。
$ cp foo.txt foo.txt.cp
$ stat foo.txt.cp
File: 'foo.txt.cp'
Size: 6 Blocks: 8 IO Block: 4096 regular file
Device: 800h/2048d Inode: 15 Links: 1
Access: (0664/-rw-rw-r--) Uid: ( 1000/huangjian) Gid: ( 1000/huangjian)
Access: 2019-02-22 13:58:18.050807588 +0800
Modify: 2019-02-22 13:58:18.050807588 +0800
Change: 2019-02-22 13:58:18.050807588 +0800
Birth: -
给 foo.txt 创建一个硬链接，inode 不变
$ ln foo.txt foo.txt.hardlink
$ stat foo.txt.hardlink
File: 'foo.txt.hardlink'
Size: 6 Blocks: 8 IO Block: 4096 regular file
Device: 800h/2048d Inode: 13 Links: 2
Access: (0664/-rw-rw-r--) Uid: ( 1000/huangjian) Gid: ( 1000/huangjian)
Access: 2019-02-22 13:56:35.097721182 +0800
Modify: 2019-02-22 13:56:31.645684665 +0800
Change: 2019-02-22 13:58:38.651024368 +0800
Birth: -
给 foo.txt 创建一个软链接，inode 改变了
$ ln -s foo.txt foo.txt.softlink
$ stat foo.txt.softlink
File: 'foo.txt.softlink' -> 'foo.txt'
Size: 7 Blocks: 0 IO Block: 4096 symbolic link
Device: 800h/2048d Inode: 16 Links: 1
Access: (0777/lrwxrwxrwx) Uid: ( 1000/huangjian) Gid: ( 1000/huangjian)
Access: 2019-02-22 13:59:06.099312909 +0800
Modify: 2019-02-22 13:59:00.707256254 +0800
Change: 2019-02-22 13:59:00.707256254 +0800
Birth: -
mv 移动文件的时候，inode 不变。但是如果系统中有多个硬盘，mv 的时候是从一个硬盘移动到另一个硬盘的话，inode 会改变。
$ ls -lhi foo.txt*
13 -rw-rw-r-- 2 huangjian huangjian 6 Feb 22 13:56 foo.txt
15 -rw-rw-r-- 1 huangjian huangjian 6 Feb 22 13:58 foo.txt.cp
13 -rw-rw-r-- 2 huangjian huangjian 6 Feb 22 13:56 foo.txt.hardlink
16 lrwxrwxrwx 1 huangjian huangjian 7 Feb 22 13:59 foo.txt.softlink -> foo.txt
$ mv foo.txt foo.txt.bar
$ ls -lhi foo.txt*
13 -rw-rw-r-- 2 huangjian huangjian 6 Feb 22 13:56 foo.txt.bar
15 -rw-rw-r-- 1 huangjian huangjian 6 Feb 22 13:58 foo.txt.cp
13 -rw-rw-r-- 2 huangjian huangjian 6 Feb 22 13:56 foo.txt.hardlink
16 lrwxrwxrwx 1 huangjian huangjian 7 Feb 22 13:59 foo.txt.softlink -> foo.txt
修改 foo.txt.bar 的内容，硬链接也会改变，因为他们的 inode 是相同的。
$ echo "world" > foo.txt.bar
$ cat foo.txt.hardlink
world
