Linux Search

数据库搜索--只能通过文件名搜索

1. 更新数据：updatedb (default system will run the command at 4.02am)

2.搜索文件：locate 文件名

Addition: locate -r to use regular expression

Example:

locate -r 'ls$': to find the file name which end with 'ls'

locate -r '^ls': to find the file name which start with 'ls'

'.*': any length of any character

'a*': any length of a

'\<ls' : word start with ls

'\>ls': word end with ls

 

find

1. search by name：find / -name <file name> (find use wildcard: * ?)

2. search by size：find / -size +20000  找大于20M的文件

3. search by inode：find / -inum 文件或文件夹的inode

4. search by user: find / [-user/-nouser] <username>

5. search by group: find / [-group/-nogroup] <groupname>

6. search by priliege: find / -perm [/mode/-mode/mode]

a. /mode: any one match

b. -mode: contain match

c. mode: exact match

 

7. search by type: find / -type <file type>

file type: b: block device / d: directory / c: character device / p: piple / l: link / f: file / s: socket

 

8. search by time:

A. mtime: content modify time (vi, echo) --> mmin

B. atime: access time (touch) --> amin

C. ctime: file create time (chmod, chgrp, mv) --> cmin

find <path> {-mtime/-mmin/-atime/-amin/-ctime/-cmin} [+N/-N/N]

 

9. 直接处理搜索结果：

例如：查询所有inode为79706的文件，并用ll查询

find / -inum 79706 -exec ls -l {} \;

例如：查询/database/archivelogz文件夹下所有24小时以前的文件并删除

find /database/archivelog -atime 1 -exec rm {} \;

Additional: If need check before delete

find /database/archivelog -atime 1 -ok rm {} \;

 

awk

例如：查询所有uid>500的用户，显示他们的用户名和uid

awk -F: '$3>500 { print $1,$3 }' passwd

-F：表示间隔符