Linux common command exercises: WC, cut, |, tee, tail

Linux Common command-related exercises:

1, only show how many lines of/etc/inittab file, other information does not display:

#wc-L/etc/inittab | Cut-d '-f1

[Email protected] ~]# Wc-l/etc/inittab | Cut-d '-f1

26

2. The number of files in the statistics/usr/bin directory:

#ls/usr/bin | Wc-l

[Email protected] ~]# Ls/usr/bin | Wc-l

1748

3. Take out the shell of all the users on the current system and request that each shell be displayed only once and in order;

#cut-D:-f7/etc/passwd |sort-u

[Email protected] ~]# cut-d:-f7/etc/passwd |sort-u

/bin/bash

/bin/sync

/sbin/halt

/sbin/nologin

/sbin/shutdown

4, thinking: How to display the content type of each file in the/var/log directory?

[[email protected] ~]# file/var/log/* or file ' Ls/var/log '

/var/log/anaconda.ifcfg.log:ascii text

/var/log/anaconda.log:utf-8 Unicode 中文版 Text

/var/log/anaconda.program.log:ascii 中文版 text, with very long lines, with overstriking

5. Take out the sixth line of the/etc/inittab file;

[Email protected] ~]# head-6/etc/inittab | TAIL-1 takes the first six lines and then takes the last line through the pipe

#

6. Take out the user name and shell of the 9th user in the/etc/passwd file.

Display to the screen and save it to the/tmp/users file;

[Email protected] ~]# tail-9/etc/passwd | head-1 | Cut-d:-f1,7|tee/tmp/users

Rpcuser:/sbin/nologin Tee content is displayed on the screen and saved to the specified directory

7. Display all files starting with PA in/etc directory, and count the number of them;    

[Email protected] ~]# ls-d/etc/pa* | Wc-l

4

8, do not use a text editor, add alias Cls=clear a line of content to the current user's. bashrc file;    

[Email protected] ~]# echo "Alias Cls=clear" >>.BASHRC

[Email protected] ~]# tail. BASHRC

Alias rm= ' Rm-i '

Alias cp= ' Cp-i '

Alias mv= ' Mv-i '

# Source Global Definitions

if [-F/ETC/BASHRC]; Then

. /etc/bashrc

Fi

Alias Cls=clear

Linux common command exercises: WC, cut, |, tee, tail