8-30 File Lookup command Find usage instructions and exercises

File Lookup:
The process of locating a qualifying file on a file system;

File Finder: Locate, find
Locate: A non-real-time lookup tool that relies on a pre-built index, which is built automatically when the system is idle (periodic tasks), manually updating this database (updatedb), searching fast, and fuzzy lookups;
Find: real-time search; search speed slightly slow; exact search;

Find command:
Command use format: Find [OPTION] ... [Find Path] [Search Criteria] [Handling Action]
Find path: Default to the current path;
Search criteria: The specified search criteria, can be based on the file name, size, genus of the main group, type, etc., by default to find all the files under the specified path;
Handling actions: What to do with the eligible files; By default, output to the screen;

1. Search Conditions:
(1) Search by file name:
-name "file name": Supports the use of glob;
*, ?, []
-iname "file name": Character case insensitive, supports use of glob;

-regex "pattern": matches the entire file path string with pattern, not just the file name;

(2) According to the genus, the genus Group looks for:
-user USERNAME: Find files belonging to the owner of the specified user;

-group GROUPNAME:

-uid UserID: A file that finds the owner-specified UID of a file;
-gid GroupID:

-nouser: Find files that are not owned by the master;
-nogroup: Find files without a group;

(3) Search by file type:
-type type
F: Normal file
D: Catalogue
L: Symbolic Link
B: Block device
C: Character device
P: Named Pipes
S: Socket

(4) Combination search criteria:
With condition:-A (can be omitted), find condition 1-a find condition 2-a ...: All conditions must be met
or condition:-O, find condition 1-o find condition 2-o ...: meet one and you can

Non-conditional:-not,!,-not Find condition: cannot be a lookup condition

! A-o! B =! (A-a B)
! A-a! B =! (A-o B)

(5) Based on the file size to find:
-size [+|-] #UNIT
Unit: K, M, G

#UNIT: (#-1,#]
+ #UNIT: (#,+oo)
-#UNIT: [0,#-1]

(6) Based on time stamp:
In "Days" as the unit
-atime [+|-]#
#:[#,#+1)
+#: [#+1,oo]
-#: [0,#]
-mtime
-ctime

In "Minutes" units
-amin
-mmin
-cmin

(7) According to the authority:
-perm [/|-]mode
MODE: Exact permission match
/mode: Any one of a class of objects (U,g,o) is eligible for any of the rights, implied or conditional;
/400
-mode: Every permission specified for each class of object must be in accordance with the condition;

2. Handling actions:
-print: Default handling action
-ls: Similar to the "ls-l" operation for each file found;
-delete: Delete the found file;
-fls/path/to/somefile: The detailed path information of the found file is saved to the specified file;

-ok COMMAND {} \;
The user must be confirmed beforehand before executing the specified command for each file;
-exec COMMAND {} \;
No user confirmation required;

8-30 File Lookup command Find usage instructions and exercises