8.1 File Lookup Local;find use

File Lookup:

Find eligible files on the file system.

File Lookup: Locate, find

Non-real-time lookup (Database lookup): Locate
Real-time Find: Find

Locate

1 querying the pre-built file index database on the system/var/lib/mlocate/mlocate.db
2 builds that rely on pre-built indexed indexes are automatically made when the system is idle (recurring tasks), and the administrator manually updates the database (UpdateDB)
3 The index build process needs to traverse the entire root filesystem, consuming resources very

Working characteristics:

? Fast Search Speed
? Fuzzy Lookup
? Non-real-time lookup

? Search for the full path of the file, not just the filename
? may only search directories where the user has read and Execute permissions

Locate command

Locate KEYWORD

Useful options

 -i 不区分大小写的搜索  -n N 只列举前N个匹配项目  -r 使用正则表达式

Example

Search for a file with "conf" in the name or path
Locate conf
Use Regex to search for files ending with ". conf"
Locate-r '. conf$ '

Find

Real-time Find tool to complete file lookups by traversing a specified path

Working characteristics:

Find speed slightly slower
Exact search
Real-time Search
may only search directories where the user has read and Execute permissions

Find [OPTION] ... [Find Path] [Search Criteria] [Handling Action]
Find path: Specify a specific target path; defaults to the current directory
Search criteria: Specifies the criteria for finding criteria, such as file name, size, type, permissions, etc., by default to find all files under the specified path
Handling actions: Perform actions on eligible files, output to screen by default

Find criteria

1 refers to the search hierarchy
-maxdepth level maximum Search directory depth, specified directory 1th
-mindepth level minimum Search directory depth
2 working with files in the directory before processing the directory
-depth

3 Search by file name and Inode:

-name "file name": Support using Glob *,?, [], [^]
-iname "file name": Letter case insensitive
-inum n Search by inode number
-samefile name the same inode number file
-links n files with number of links n
-regex "pattern": matches the entire file path with pattern, not the file name

4 Depending on the genus, the genus Group looks for:

-user USERNAME: Find files that belong to the specified user (UID)
-group GRPNAME: Finding files that belong to a specified group (GID)
-uid UserID: Find the file that belongs to the specified UID number
-gid GroupID: Finding files with a specified GID number for the genus Group
-nouser: Finding files that are not owned by the master
-nogroup: Finding files that are not owned by a group

5 Find by File type:

-type TYPE: ? f: 普通文件  ? d: 目录文件  ? l: 符号链接文件  ? s：套接字文件  ? b: 块设备文件  ? c: 字符设备文件  ? p: 管道文件

Empty file or directory
-empty
Find/app-type D-empty

Find condition Combination criteria:

With:-A
Or:-O
Non:-not,!

De Morgan Law:

(not a) or (not B) = Non (A and B)
(Non-a) and (not B) = Non (A or B)

Example:

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

Find Example:

Find-name Snow.png
Find-iname Snow.png
Find/-name ".txt"
Find/var–name "log*"
Find-user Joe-group Joe
Find-user Joe-not-group Joe
Find-user Joe-o-user Jane
Find-not (-user joe-o-user Jane)
Find/-user joe-o-uid 500

Find files in the/tmp directory where the owner is not root and the file name does not start with F
Find/tmp (-not-user root-a-not-name ' F')-ls
Find/tmp-not (-user root-o-name ' F') – ls

Exclude Directory

Find all other. conf suffix files under/etc/, except for the/ETC/SANE.D directory
Find/etc-path '/ETC/SANE.D '-a–prune-o-name ". conf"
Find all the. conf suffix files under/etc/, except/ETC/SANE.D and/etc/fonts two directories
Find/etc (-path "/ETC/SANE.D"-o-path "/etc/fonts")-a-prune-o-Name ". conf

Depending on the file size, look for:

-size [+|-] #UNIT common units: K, M, G,c (byte)
#UNIT: (#-1, #] such as: 6k (5k,6k]
-#UNIT: [0,#-1] such as: -6k = [0,5k]
+ #UNIT: (#,∞) such as: +6k (6k,∞)

Find/-size +10000c #查找出大于10000000字节的文件 (c: Bytes, W: double word, K:KB,M:MB,G:GB)
Find/-size-1000k #查找出小于1000KB的文件

Based on timestamp: "Days" as the unit

1-atime find the last n24-hour files accessed in the system
Find/-atime-2 # finds files accessed in the last 48 hours of the system
2-mtime
Find/-mtime-1 #查找在系统中最后24小时里修改过的文件
3-ctime find the last n24-hour changed state file in the system

In "Minutes" units

1-amin find the last n minutes of files accessed in the system
Find/-amin-10 # finds files accessed in the last 10 minutes of the system
2-mmin
Find/-mmin-5 # finds files that have been modified in the last 5 minutes of the system
3-cmin find the last n minutes of the system changed state of the file

Search by permissions:

-perm [/|-]mode
MODE: Exact permission match
/mode: The permission of any class (U,g,o) object can be a match, or a relationship, + from the CENTOS7 start elimination
-mode: Each class of objects must have the specified permission, and the relationship

0 indicates no concern
Find-perm 755 matches a file with a permission pattern of exactly 755
As long as any person has write permission, Find-perm +222 will match
find-perm-222 matches only when everyone has permission to write
FIND-PERM-002 matches only if other people (other) have write permissions

Handling actions

-ls: Similar to performing a "ls-l" command on a found file
-delete: Delete the found file
-fls file: Long format information for all files found is saved to the specified files
-ok COMMAND {} \; Executes commands specified by command on each file found, and interactively asks the user to confirm each file before executing the command
-exec COMMAND {} \; Executes commands specified by command on each file found
When you use the OK or EXEC option, you must end with \; where {} represents all the results found by the Find command. As a result, there are sometimes too many command errors, or the command does not support the standard input through the pipe pass parameter.

8.1 File Lookup Local;find use