Ch1. Access the Command Line

 

Virtual consoles:

Alt+Ctrl+Fn
Alt+Fn    (CLI only)
Alt+ -> or -<
[root@master Desktop]# chvt 6      (where 6 is the tty number)
[root@master Desktop]# tty
/dev/pts/0                         (Pesudo terminal screen)
[root@master Desktop]# tty
/dev/tty2                          (Tele type terminal)

To use mouse in TTY envirnment, install the GPM package:
[root@master ~]# yum install gpm
[root@master ~]# systemctl start gpm**

Shell basics:

[root@master ~]# clear            (or Ctrl+l)
[root@master ~]# reset
[root@master ~]# ls
[root@master ~]# ls -l
[root@master ~]# ls --all
[root@master ~]# ls -a
[root@master ~]# ls -la 
[root@master ~]# ls -la /home
[root@master ~]# exit             (or Ctrl+d)

[root@master ~]# date --help
	Usage: date [OPTION]... [+FORMAT]
	  or:  date [-u|--utc|--universal] [MMDDhhmm[[CC]YY][.ss]]
	[ ] surround optional items
	... represents an arbitrary-length list of items of that type
	| means only one of them can be specified
	<> represents variable data. For example <filename>**

The GNOME desktop environment:(GNOME v3)

**The default is "GNOME Classic", similar to GNOME 2
"Modern GNOME 3" is also available
GNOME help:
1- F1
2- Applications> Documentation> Help
3- [root@master ~]#yelp**

Examples of simple commands:

**[root@master ~]# date 
[root@master ~]# cal
[root@master ~]# cal 2016
[root@master ~]# cal 3
[root@master ~]# cal 3 2016
[root@master ~]# date +%R
[root@master ~]# date +%x
[root@master ~]# passwd
[root@master ~]# passwd abeer
[root@master ~]# file /etc/passwd
[root@master ~]# file /home
[root@master ~]# which passwd
[root@master ~]# file /bin/passwd
[root@master Desktop]# head /etc/passwd
[root@master Desktop]# head -n 3 /etc/passwd
[root@master Desktop]# head -3 /etc/passwd
[root@master Desktop]# head /etc/passwd -n 3
[root@master Desktop]# tail /etc/passwd
[root@master Desktop]# tail -n 3 /etc/passwd
[root@master Desktop]# tail -3 /etc/passwd
[root@master Desktop]# tail /etc/passwd -n 3
[root@master Desktop]# wc /etc/passwd
[root@master Desktop]# wc -lwc /etc/passwd
[root@master Desktop]# wc -l /etc/passwd**

Tab completion:

[root@master Desktop]# pas   <TAB>
passwd       paste        pasuspender
[root@master Desktop]# pass   <TAB>
[root@master Desktop]# passwd
[root@master Desktop]# ls /etc/pas    <TAB>
[root@master Desktop]# useradd --     <TAB>

Command history:

[root@master ~]# cat .bash_history 
[root@master ~]# history
[root@master ~]# !88
[root@master ~]# !-10
[root@master ~]# !ls       (the most recent command)
[root@master ~]# !!
[root@master ~]# history -c           (to clear the history)
Note: new command are loaded into buffer and shown in the history command when we exit the shell

Others:

Ctrl+a     Jump to the beginning of the command line.
Ctrl+e     Jump to the end of the command line.
[root@master ~]# ls ; date ; cal
[root@master ~]# ls && date         (logical AND)
[root@master ~]# ls /div || date    (logical OR)
[root@master ~]# ls /etc/passwd
[root@master ~]# head <ESC>.        (to use the last argument)

[root@master ~]# head -n 3 \\        (To write one command in more than one line, use a backslash character (\\))      
/usr/share/dict/words \\
/etc/passwd                
	==> /usr/share/dict/words <==
	A
	AA
	AAA
	
	==> /etc/passwd <==
	root:x:0:0:root:/root:/usr/bin/zsh
	daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin
	bin:x:2:2:bin:/bin:/usr/sbin/nologin

Useful Command-line Editing Shortcuts :

 

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