Linux Exercises-2 basic commands

1. Filter out the known current directoryetcall of the first-level catalogs (not includingetcSubdirectories and hidden directories of directories below directory, only one level directory)

Ls-l | grep ' ^d '

Ls-p | grep '/$ '

Ls-f | grep '/$ '

Find. -maxdepth 1-type D! -name "."

2 , quick return to last working directory

CD-

each time the directory is toggled, the system will save the last working directory to the variable oldpwd in which CD- actually called the oldpwd variables

3 , in a directory, the fastest speed to find the most recently updated files.

Ls-lrt

with R reverse display, put the latest files in the last

4 , find out /data/test/ directory under 7 days before the log file is deleted

Simulation Scenarios

#!/bin/bash

For n in ' seq 14 ':

Do

Date-s "2018/04/$n";

Touch access_www_$ (date +%f). log;

Done

Find/data/test-type F-mtime +7 | Xargs rm-f

Find/data/test-type f-mtime +7-exec rm-f {} \;

5 , debugging system services, you want to see the system log in real time /var/log/messages the update, how to do

Tail-f/var/log/message

Tailf/var/log/message

6 , Print /etc/passwd and displays the file line number

NL/ETC/PASSWD # does not display a space line line number, the same Cat-b

cat-n/etc/passwd # Show All line numbers

vim/etc/passwd Command mode input Set Nu

grep-n./etc/passwd   # . represents any single character and does not filter out space lines

Grep-n ". *"/ETC/PASSWD #. * Denotes all characters, can filter out the empty cells

Grep-n "*"/etc/passwd

awk ' {print nr,$0} '/etc/passwd

Less-n/etc/passwd

7 , set up a service to boot from

Chkconfig a service that is actually in rc#.d/ a soft link to the service command is created in the directory. In the script there are assigned start sequence number and stop sequence number

in sshd as an example, note the last line 2345 represents 2345 of the Level next self-starter - is the start sequence number - is the stop sequence number.

you can write a script yourself, format the same, you assign the start number and stop number, cannot be greater than About . Then chkconfig-add sservice_name. You can manage it through chkconfig .

8 , Linu See Chinese garbled, how to solve

Introduction to Character Sets

the character set is simply a set of text symbols and their encoding. Each country has a different character set for expressing its own language. The United States is the ASCII code, China is GBK23, in order to unify the character set standard, appeared the integration each country's character set UTF-8

1. Temporary entry into force

Export lang= "ZH_CN. UTF-8 "

2. Permanent entry into force

Echo ' lang= ' ZH_CN. UTF-8 "' >/etc/sysconfig/i18n

source/etc/sysconfig/i18n

9 , the practice of packing commands

1, with Tar Packing / etc Entire directory (packaged and compressed)

TAR-ZCVF etc.tar.gz/etc

2, with Tar Packing / etc Entire directory (packaged and compressed, but need to be excluded /etc/services files)

TAR-ZCVF etc.tar.gz/etc --exclude=/etc/services

3, the 1) Click the command to unzip the package to /data/test directory under

TAR-XVF etc.tar.gz-c/data/test/

4, will /data/test under the all . txt File Packaging

Find/data/test-type f-name "*.txt" | Xargs Tar zcvf txt.tar.gz

Ten , known Test.txt the content is "I am Cbl,myphone is 12345678"

1, filter out the file " CBL "and" 12345678 the string

Awk-f "[,]+" ' {print $3,$7} ' test.txt

Cut-c 6-8,20-test.txt

2, filter out the file " cbl,12345678 the string

Awk-f "[,]+" ' {print $], ' $7} ' test.txt

Linux Exercises-2 basic commands