Unix Shell: Find Files(3)

1. Find command: -user, -group
We can use -user option to filter files or directories belonging to a specific user.
1) list all files, from description, all files belong to user "aubinxia"(first one), and belong to group "aubinxia" (second one)
2) We use find command to list files belonging to user "aubinxia"
3) "!" means not. We use find command to list all files not belonging to user "aubinxia"
4) We use find command to list files belonging to group "aubinxia"
5) We use find command to list all files not belonging to group "aubinxia"

 aubinxia@aubinxia-fastdev:~/Desktop/xxdev$ ls -lrt  
 total 4  
 -rw-rw-r-- 1 aubinxia aubinxia  0 Jul 4 11:58 oc  
 -rw-rw-r-- 1 aubinxia aubinxia  0 Jul 4 11:58 ob  
 -rw-rw-r-- 1 aubinxia aubinxia  0 Jul 4 11:58 oa  
 drwxrwxr-x 2 aubinxia aubinxia 4096 Jul 4 11:58 dir  
 aubinxia@aubinxia-fastdev:~/Desktop/xxdev$ find * -user aubinxia  
 dir  
 dir/d2  
 dir/d1  
 oa  
 ob  
 oc  
 aubinxia@aubinxia-fastdev:~/Desktop/xxdev$ find * ! -user aubinxia  
 aubinxia@aubinxia-fastdev:~/Desktop/xxdev$ find * -group aubinxia
 dir
 dir/d2
 dir/d1
 oa
 ob
 oc
 aubinxia@aubinxia-fastdev:~/Desktop/xxdev$ find * ! -group aubinxia
 aubinxia@aubinxia-fastdev:~/Desktop/xxdev$ 
 

2. Find command: -perm
-perm option allows find command to find files whose permission are satisfied.

1) List all files in local directory
2) find all files in local directory whose permission is exactly "664"(rw-rw-r--)
3) find all files in local directory whose permission is exactly "662"(rw-rw--w-)

 aubinxia@aubinxia-fastdev:~/Desktop/xxdev$ ls -lrt  
 total 4  
 -rw-rw-r-- 1 aubinxia aubinxia  0 Jul 4 11:58 oc  
 -rw-rw-r-- 1 aubinxia aubinxia  0 Jul 4 11:58 ob  
 -rw-rw-r-- 1 aubinxia aubinxia  0 Jul 4 11:58 oa  
 drwxrwxr-x 2 aubinxia aubinxia 4096 Jul 4 11:58 dir  
 aubinxia@aubinxia-fastdev:~/Desktop/xxdev$ find * -perm 664 -ls  
 920603  0 -rw-rw-r--  1 aubinxia aubinxia    0 Jul 4 11:58 dir/d2  
 920593  0 -rw-rw-r--  1 aubinxia aubinxia    0 Jul 4 11:58 dir/d1  
 131137  0 -rw-rw-r--  1 aubinxia aubinxia    0 Jul 4 11:58 oa  
 131266  0 -rw-rw-r--  1 aubinxia aubinxia    0 Jul 4 11:58 ob  
 134220  0 -rw-rw-r--  1 aubinxia aubinxia    0 Jul 4 11:58 oc  
 aubinxia@aubinxia-fastdev:~/Desktop/xxdev$ find * -perm 662 -ls  
 aubinxia@aubinxia-fastdev:~/Desktop/xxdev$   

=========================================
1) List all files in local directory
2) Find all files in local directory whose permission satisfies: +444(r--r--r--), there are 3 read bits turned up, as long as the file's permission has one of these 3 bits  on, then it will be selected
3) Find all files in local directory whose permission satisfies: +777(rwxrwxrwx), as long as file's permission has one of these 9 bits on, then it will be selected.

 aubinxia@aubinxia-fastdev:~/Desktop/xxdev$ ls -l  
 total 4  
 drwxrwxr-x 2 aubinxia aubinxia 4096 Jul 4 11:58 dir  
 -rw-rw-r-- 1 aubinxia aubinxia  0 Jul 4 11:58 oa  
 -rw-rw-r-- 1 aubinxia aubinxia  0 Jul 4 11:58 ob  
 -r--r--r-- 1 aubinxia aubinxia  0 Jul 4 11:58 oc  
 aubinxia@aubinxia-fastdev:~/Desktop/xxdev$ find * -perm +444 -ls  
 920592  4 drwxrwxr-x  2 aubinxia aubinxia   4096 Jul 4 11:58 dir  
 920603  0 -rw-rw-r--  1 aubinxia aubinxia    0 Jul 4 11:58 dir/d2  
 920593  0 -rw-rw-r--  1 aubinxia aubinxia    0 Jul 4 11:58 dir/d1  
 131137  0 -rw-rw-r--  1 aubinxia aubinxia    0 Jul 4 11:58 oa  
 131266  0 -rw-rw-r--  1 aubinxia aubinxia    0 Jul 4 11:58 ob  
 134220  0 -r--r--r--  1 aubinxia aubinxia    0 Jul 4 11:58 oc  
 aubinxia@aubinxia-fastdev:~/Desktop/xxdev$ find * -perm +777 -ls  
 920592  4 drwxrwxr-x  2 aubinxia aubinxia   4096 Jul 4 11:58 dir  
 920603  0 -rw-rw-r--  1 aubinxia aubinxia    0 Jul 4 11:58 dir/d2  
 920593  0 -rw-rw-r--  1 aubinxia aubinxia    0 Jul 4 11:58 dir/d1  
 131137  0 -rw-rw-r--  1 aubinxia aubinxia    0 Jul 4 11:58 oa  
 131266  0 -rw-rw-r--  1 aubinxia aubinxia    0 Jul 4 11:58 ob  
 134220  0 -r--r--r--  1 aubinxia aubinxia    0 Jul 4 11:58 oc  

=============================================
1) List all files in local directory
2) Find all files in local directory whose permission satisfies:  -664(rw-rw-r--), there are 5 bits on. As long as file's permission has all these 5 bits on, it will be selected, even if other bits are also on. So in this case, all files are selected unless oc.
3) Find all files in local directory whose permission satisfies: -444(r--r--r--), there are 3 bits on. As long as file's permission has all these 3 bits on, it will be selected. So in this case, all files are selected.

 aubinxia@aubinxia-fastdev:~/Desktop/xxdev$ ls -l  
 total 4  
 drwxrwxr-x 2 aubinxia aubinxia 4096 Jul 4 11:58 dir  
 -rw-rw-r-- 1 aubinxia aubinxia  0 Jul 4 11:58 oa  
 -rw-rw-r-- 1 aubinxia aubinxia  0 Jul 4 11:58 ob  
 -r--r--r-- 1 aubinxia aubinxia  0 Jul 4 11:58 oc  
 aubinxia@aubinxia-fastdev:~/Desktop/xxdev$ find * -perm -664 -ls  
 920592  4 drwxrwxr-x  2 aubinxia aubinxia   4096 Jul 4 11:58 dir  
 920603  0 -rw-rw-r--  1 aubinxia aubinxia    0 Jul 4 11:58 dir/d2  
 920593  0 -rw-rw-r--  1 aubinxia aubinxia    0 Jul 4 11:58 dir/d1  
 131137  0 -rw-rw-r--  1 aubinxia aubinxia    0 Jul 4 11:58 oa  
 131266  0 -rw-rw-r--  1 aubinxia aubinxia    0 Jul 4 11:58 ob  
 aubinxia@aubinxia-fastdev:~/Desktop/xxdev$ find * -perm -444 -ls  
 920592  4 drwxrwxr-x  2 aubinxia aubinxia   4096 Jul 4 11:58 dir  
 920603  0 -rw-rw-r--  1 aubinxia aubinxia    0 Jul 4 11:58 dir/d2  
 920593  0 -rw-rw-r--  1 aubinxia aubinxia    0 Jul 4 11:58 dir/d1  
 131137  0 -rw-rw-r--  1 aubinxia aubinxia    0 Jul 4 11:58 oa  
 131266  0 -rw-rw-r--  1 aubinxia aubinxia    0 Jul 4 11:58 ob  
 134220  0 -r--r--r--  1 aubinxia aubinxia    0 Jul 4 11:58 oc  

3. Find command: -size
size option helps find command to filter files by file size
1) List all files in local directory with size information
2) "-size 7c" means find command will list all files with 7 bytes. c means byte here.
3) "-size 13c" means find command will list all files with 13 bytes, c means byte here.
4) "-size -16c" means find command will list all files less than 16 bytes. "-" means less than.
5) "-size +16c" means find command will list all files greater than 16 bytes. "+" means greater than.
6) "-size +11k" means find command will list all files greater than 11kb."k" means kb.
7) "-size +11M" means find command will list all files greater than 11Mb.  "M" means Mb.

 aubinxia@aubinxia-fastdev:~/Desktop/xxdev$ ls -lrt  
 total 13340  
 -rw-rw-r-- 1 aubinxia aubinxia    7 Jul 4 15:14 o1  
 -rw-rw-r-- 1 aubinxia aubinxia    13 Jul 4 15:14 o2  
 -rw-rw-r-- 1 aubinxia aubinxia    16 Jul 4 15:14 o3  
 -rw-rw-r-- 1 aubinxia aubinxia  13312 Jul 4 15:18 o4  
 -rw-rw-r-- 1 aubinxia aubinxia 13631488 Jul 4 15:19 o5  
 aubinxia@aubinxia-fastdev:~/Desktop/xxdev$ find * -size 7c  
 o1  
 aubinxia@aubinxia-fastdev:~/Desktop/xxdev$ find * -size 13c  
 o2  
 aubinxia@aubinxia-fastdev:~/Desktop/xxdev$ find * -size -16c  
 o1  
 o2  
 aubinxia@aubinxia-fastdev:~/Desktop/xxdev$ find * -size +16c  
 o4  
 o5  
 aubinxia@aubinxia-fastdev:~/Desktop/xxdev$ find * -size +11k  
 o4  
 o5  
 aubinxia@aubinxia-fastdev:~/Desktop/xxdev$ find * -size +11M  
 o5