Linux Growth Path 1

Spring

Despair bedroom spring white lined clothes, white door lonely Italy.

The Red House is cold across the rain, the bead foil floating lights alone.

Long Lu should be sad spring rest night, remnants of the dream faintly.

Oh He Yuda, Wan Yun earrings fly.

-----------------------------------------------------Ready Go

First, practice a practice

1, Statistics/usr/bin Directory of the number of files

#ls/usr/bin/| Wc-l

2. To remove the shell of all users on the current system, the requirements are as follows:

1) Each shell is displayed only once,

2) display in order;

# cut-d:-f7/etc/passwd | Sort-u

650) this.width=650; "Width=" 395 "height=" 103 "id=" image_operate_48191439606353540 "src=" http://s11.sinaimg.cn/ mw690/003tdxq6ty6uecnb0ru5a&690 "alt=" 003tdxq6ty6uecnb0ru5a&690 "/>

3. Create a new A.txt file and take out the 5th line of the file

# Nano A.txt

# head-5/root/a.txt | Tail-1

4. Do not use a text editor to add the alias Cls=clear line to the current user's. bashrc file
#echo "Alias Cls=clear" >> ~/.BASHRC

Second, remember

Sort
-N: Numeric size sorting
-R: Descending sort
-T: Field delimiter
-K: Which field is the keyword to sort
-U: The same row is only displayed once after sorting
-F: Ignore case when sorting

WC (Word cound)
Number of lines of words bytes
-L: Show only the number of rows
-C: Show only the number of bytes
-W: Displays only the number of words
-L: The longest line contains the number of characters

Cut
-D: Specify delimiter, default is a space
-F: Specify the fields to display

Head: View Top N rows
Tail: View after n rows

: Overwrite output
>>: Append output

&>: Redirect standard output or error output to the same file

<: Input redirection
<<: Generate document usage here >>file<<eof
111
222
Eof
Display as: 111
222

Tee: Can be saved to the file and output to the screen

This article is from the "Buy Girl's Little Match" blog, please be sure to keep this source http://newstbird.blog.51cto.com/10549212/1684816

Linux Growth Path 1