Shell quotes are useful

1 single quotation marks

Single quotation marks can be used to restore the literal meaning of characters, to implement the function of shielding metacharacters, single quotes must be used in pairs

[Email protected]~]# echo ' $JAVA _home '

Special features $JAVA _home #实现屏蔽 $

[[Email protected]~]# echo ' CD \home '

CD \home #实现屏蔽转义字符 \

2 double Quotes

Double quotation marks are basically the same as single quotes, but they do not mask the function of the $ ' \ Three metacharacters, and if you want to block them, you must precede them with a \,

[Email protected]~]# echo "$JAVA _home" #双引号直接输出了变量

/usr/java/jdk1.7.1_8

[Email protected]~]# echo "It s your book"

It ' s your book

[[Email protected]~]# echo ' \ $JAVA _home ' #用 \ Escape, output the following characters directly

$JAVA _home

3 anti-Quote

Reverse quotation marks are command substitution, replacing command characters with command result output

[Email protected]~]# echo "Today is ' Date '" #直接输出date命令的结果

Today is Fri Dec 11:50:20 CTS 2016

This article is from the "Practical Linux knowledge and Skills sharing" blog, please be sure to keep this source http://superleedo.blog.51cto.com/12164670/1887616

Shell quotes are useful