linux--File Lookup

2017-08-11 19:12:55 @ but may this heart have no grudge

A simple summary of common search methods for files in Linux today

In short, the use of the locate and find commands

Locate Query File Introduction

Syntax locate [options] keyword

Command options

- i case-insensitive search

-N enumeration of the top n items

-R Support regular

This command is not real-time query, but query the system above the pre-built file index library file /var/lib/mlocate/mlocate.db

UpdateDB Command Update locate database or exit and re-enter

The test is as follows:

query all files ending with. conf (because the result is too long, only the part is truncated), and then /app the directory to create the file test, query /app/test, after updating the locate database, query again.

Easier to use, faster to find

Find File Description

syntax Format find [ Find path ](default current)[ find Condition ] [ processing Action ](default is output to terminal)

Features real-time query, slow, but more complete function

[ search Criteria ] (Common)

-maxdepth level Specifies the maximum search depth

-minxdepth level Minimum search depth

-name exact name-based lookups

-iname Exact Lookup lookup based on name ignoring case

-regex Support Regular default to (emacs Standard)

-regextype Egrep-regex supports egrep with standard regular

-user user name based on file owner Lookup

-group group name based on The search of file group

-perm search based on permissions

-nouser to find files without owner

-nogroup finding files with no group

-type file Type-based lookups

? F: Normal file

? D: Catalog Files

? L: Symbolic Link File

? s : Socket file

? B: Block device Files

? C: Character device Files

? P: Pipeline Files

-size [+|-] #UNIT find eg-size based on file size 5M

Common units:K, M, G,C(byte)

+6m indicates a lookup range of (6M,∞]

-6m indicates a lookup range of [0,5m]

6M indicates a lookup range of (5m,6m]

-atime,-mtime,-ctime(in days)

-amin,-mmin,-cmin(in minutes)

the use is similar to-size

For example

-atime-3 = [0,3]

-atime +3 = {4,∞)

-atime 3 = [3,4]

Support -a(default)-o-not(or ! ) ) Check the conditions of the review

Some of the options are tested below

Find files with a maximum depth of 3 under the/app directory

Find files with the name A.1 in the current directory; Find files of the current directory type as normal files

use-regextype grep to specify the type of grep that can be used

for -perm based on permissions to find the description and test the following

-perm 444 represents a file that queries a specified permission of 444

-perm/444 means finding a file (or relationship) with 4 in the Ugo

-perm/044 means to find Any one of the 4 files in Go,0 means no consideration for this bit permission

-perm-044 for files (and relationships) that look for G and o are 4 permissions

TestThe following,/app create files test1,test2, and change their permissions to test as follows

[ processing Action ] ( common )

-ls The query file information length list

-delete Delete a queried file

-fls filename Lists the length of the queried file and stores it in filename

-ok comman \; the query file is Command operation, inquiry way to carry out each time Command Operation

-exec and -ok , but not the command operation of each file in the form of a query

Ps:{} represents a file referencing a query

For example: Create a file test1-10below/app, find and delete files test1-9

Summing up, for the method of finding files locate fast, but not real-time query, function is relatively single, find function is more complete, real-time query can be combined with other commands to achieve more operations, but the search speed is slow.

linux--File Lookup