Linux commands (3) echo

Linux of the Echo Command , in the Shell extremely popular in programming , Print variables under the terminal value is often used. , Echo command in the build Shell play an important role in scripting

1. command Format

Echo[options] [String]

2. Command function

List all subdirectories and files in the destination directory

3. Command Parameters

- N do not wrap at the end of the line

The--HELP displays help information on the standard output.

the--version outputs the version information on the standard output and exits.

-e If the following characters appear in the string, they are handled in particular, not as a general

Text output:

\a issued a warning sound;

\b Delete the previous character;

\c finally not add the line break symbol;

\f the line but the cursor remains in its original position;

\ n wraps and the cursor moves to the beginning of the line;

\ r the cursor moves to the beginning of the line, but does not wrap;

\ t insert tab;

\v is the same as \f ;

\ \ Insert \ character;

\NNN inserts the ASCII characterrepresented by the NNN (octal) ;

4. Command Instances

Example 1: Entering a line of text and displaying it on standard output

[Email protected] data]# echo I am boy

I am boy

Example 2: Writing a string directly to a file

[email protected] data]# cat Ttt.txt

Asdfasdfasdfasdf

Asfasdfasdfasdfasdf

Dddddddddddddddddddddddd

[[email protected] data]# echo ' Hello word ' >ttt.txt

[email protected] data]# cat Ttt.txt

Hello Word

Example 3:echo-n non-newline output

[[email protected] ~]$ echo-n "123"; Echo 456

123456

Example 4:echo-e handling special characters

[Email protected] ~]$ echo-e "A\BBCD"

Bcd

[Email protected] ~]$ echo-e "A\NBCD"

A

Bcd

Reference:http://blog.csdn.net/lizhi200404520/article/details/8819762

Linux commands (3) echo