Linux Fundamentals: 10, basic commands (4)

Query file type and file Location command)

File

Role: View the file type (the file type under Linux does not differentiate after the prefix name)

Syntax: file [options] filename

=================================================================================[[email protected]  ~]# file /etc/passwd/etc/passwd: ascii text                #文本文档 [[email protected] ~]# file /etc/etc:  directory                        #目录文档 [[email protected] ~]# file /bin/ls           #二进制文件/bin/ls: elf 32-bit lsb executable,  intel 80386, version 1  (SYSV), dynamically linked  (uses shared  LIBS), for gnu/linux 2.6.18, stripped[[email protected] ~]# file  test11.gz        #压缩文件test11 .gz: gzip compressed data,  was  "Test11",  FROM&NBSp unix, last modified: thu mar  5 05:30:10 2015========================= ========================================================

which

Function: Search command with

Syntax: which command

PS: Search only under the system-defined path path.

=================================================================================[[email protected] ~]# which Chkconfig/sbin/chkconfig#which can only check commands under PATH variable paths [[email protected] ~]# which Cd/usr/bin/which:no CD in (/usr/local/ Sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin) [[email protected] ~]# type CDCD is a shell builtin #因为此命 Order is a system built-in command, so you cannot find the # extension, path variable in path [[email protected] ~]# echo $PATH/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/ sbin:/usr/bin:/root/bin=================================================================================

Whereis

Function: Locates Source/binary and manuals sections for specified files.

Syntax: whereis [options] Keyword

Options:

-B only find files in binary format;

-M only find files under the manual path of the instruction manual file;

-S only find files from source;

-U finds other special files that are not in the above three parameters.

=================================================================================[[email protected] doc]# Whereis Vimvim:/usr/bin/vim/usr/share/vim/usr/share/man/man1/vim.1.gz[[email protected] doc]# whereis-m Vimvim:/usr/share/ Man/man1/vim.1.gz[[email protected] doc]# whereis-b Vimvim:/usr/bin/vim/usr/share/vim============================= ====================================================

Locate

Role: Querying files from a specific database

Syntax: Locate keywords

Installation: Yum install-y mlocate, need to update the database with updatedb command after installation is complete

Database files:/var/lib/mlocate/mlocat.db

================================================================================= #安装locate [[email protected] Doc ]# Yum install mlocate# before use updatedb [[email protected] doc]# Locate Test11.gzlocate:can not stat () '/var/lib/mlocate/ Mlocate.db ': No such file or Directory[[email protected] doc]# Updatedb[[email protected] doc]# locate Test11.gz/root/test 11.gz#db file location [[email protected] doc]# ls-l/var/lib/mlocate/mlocate.db-rw-r-----. 1 root slocate 769272 Mar 15:39/var/lib/mlocate/mlocate.db======================================================= ==========================

Find

Description: The most powerful query tool.

Syntax: Find [-h] [-l] [-p] [-D debugopts] [-olevel] [path ...] [Expression]

An expression:

• -mtime to change the file content time for the search criteria query file

We agreed in advance to push forward 24 hours from the present time for the 1th day, N=1. And so on the first day and then push forward 24 hours is the 2nd day, n=2 ...

-mtime N-N+1 is a number, meaning to query the first day of the day 24 hours of the contents of the document changed;

-mtime +n: Meaning to query n+1 days ago (without n+1 day itself) has been changed the contents of the document;

-mtime-n: Lists files that have been altered in n days (including the N-day itself);

-newer File:file is a saved file that lists files earlier than the file was modified.

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Excerpt from the bird's-brother tutorial

As you can see, when the n=4

-mtime 4 is the search for the 5th day to change the content of the file;

-mtime +4 is a query 5 days ago To change the content of the file;

-mtime-4 is a file that queries for changes to content within 4 days.

• -mmin with-mtime, just n does not represent the number of days, represents minutes.

• -type querying files by file type for search criteria

File type: F (normal file), D (directory file), l (link file), s (socket), p (pipeline), C (character file) and B (block device).

• -I ignores case of query condition

• -inum queries the file with the inode number of the file for the query criteria.

• -maxdepth followed by numbers, the number of layers representing the maximum query path, 0,1,2 ...
  

================================================================================= #查询家目录一天之内修改过的文件 [[email  Protected] ~]# find . -mtime 0|xargs ls -dldr-xr-x---.  5 root  ROOT  4096 MAR 10 14:50 .-RW-------.  1 root root 12863  mar  9 23:19 ./.bash_history-rw-r--r--.  1 root root    175 mar 10 00:04 ./.bashrc-rw-r--r--.  1 root root    96  MAR 10 01:17 ./CRONTAB.SH-RW-------.  1 root root   129  mar 10 15:52 ./.lesshst-rw-r--r--.  1 root root      8 mar 10 00:23 ./newfile# querying Common Files under the DIR4 directory [[Email protected] ~]# find  ./dir4 -type f|xargs ls -l-rw-r--r--.  1 root root 0 mar   5 04:58 ./dir4/03/test03-rw-r--r--.  1 root root 0 mar  5 04:35 ./dir4/03/ Test4-rw-r--r--.  1 root root 0 mar  5 04:34 ./dir4/dir3/test3# How do I not query the normal files under subdirectories? [[email protected] ~]# find ./dir4 -maxdepth 1 -type f     #由于dir4下面没有普通文件, so empty [[email protected] ~]# find ./dir4 -maxdepth 2 - type f    #当我们向下延伸一层后, can be found on the 2-layer file./dir4/dir3/test3./dir4/03/test03./dir4/03/test4============= ====================================================================

-perm Permissions Detailed

-perm Digital Permissions (3-bit), indicating that the match must match this right strictly

-perm-Digital Permissions (3-bit), indicating that the match must be not less than this permission

-perm/Digital Permissions (3-bit), which indicates that any group in the match Ugo contains any of the normal permissions in the required permission.

-perm/Digital Permissions (4-bit), and 3-bit digital permission rules are the same, except that special permissions and normal permissions are considered separately

-perm+ Digital Permissions (3-bit), has been/replaced

================================================================================= #分别创建不同权限的文件 [[email  protected] ~]# ll perm|awk  ' nr>1{printf ("perm:%-11sname:%s\n", $1,$9)} ' perm:----------     name:001perm:-----w----   name:002perm:---------x     name:003perm:-r--------     name:004perm:---------t    name : 005perm:-r-s------     name:006perm:-------rw-    name:007perm:- --x------     name:017perm:-----w-rw-   name:037perm:----rw-rw-    name:077perm:---x-w-r--    name:177perm:--w-rw-rw-  name:377perm:- rw-rw-rw-  name:777# Find permission 066  that is---rw-rw-[[email protected] perm]# find .  -perm 066 -ls |sed  ' s/[[:space:]]\+/ /g ' |cut -d  '   '  -f  3,11 ----rw-rw- ./077     #只有数字 "066" Match strictly [[email protected] perm]# find . -perm  /066 -ls|sed  ' s/[[:space:]]\+/ /g ' |cut -d  '   '  -f 3,11-----w----  ./002     #/066, as long as the 9-bit permission has all matching R or W---x-w-r-- ./177-------rw- ./007-- w-rw-rw- ./377----rw-rw- ./077-rw-rw-rw- ./777-----w-rw- ./037[[email protected]  perm]# find . -perm -066 -ls|sed  ' s/[[:space:]]\+/ /g ' |cut -d   '   '  -f 3,11--w-rw-rw- ./377     #- 066, as long as no less than 066 permissions are matched----rw-rw- ./077-rw-rw-rw- ./777================================================== ===============================

Stat

Role: View three times

Syntax: Stat file/dir

=================================================================================[[email protected]  ~]# stat test11.gz  file:  ' test11.gz '   Size: 122              Blocks: 8           io block: 4096   regular filedevice: 802h/2050d       Inode: 12133       Links:  1access:  (0644/-rw-r--r--)   Uid:  (    0/    root)    Gid:  (    0/    root) access: 2015-03-10  14:50:52.616930866 +0800Modify: 2015-03-05 05:30:10.555977000 +0800Change:  2015-03-10 14:50:44.910931488 +0800================================================================= ================

PS: Changing CTime does not necessarily change mtime

PS: Change Mtime will be changed CTime

This article is from the "30 Demon People" blog, please make sure to keep this source http://301ren.blog.51cto.com/8887653/1619114

Linux Fundamentals: 10, basic commands (4)