Linux系统--echo命令的使用说明

一、echo命令的基本语法

echo 命令 - 显示一行文本

echo [option] [string]

SYNOPSIS(总览) echo[OPTION]... [STRING]... DESCRIPTION(描述) 允许在标准输出上显示STRING(s). -n 不输出行尾的换行符. -e 允许对下面列出的加反斜线转义的字符进行解释. -E 禁止对在STRINGs中的那些序列进行解释. --help 显示帮助并退出(须单独运行) --version 输出版本信息并退出(须单独运行)

二、实例说明：

1、在终端显示一行消息

[root@localhost test]# echo 'hello world!' hello world!

2、打印变量的值

[root@localhost test]# x=123 [root@localhost test]# echo $x 123

3、打印一行带有双引号的文本

[root@localhost test]# echo 'welcome to "beijing"' welcome to "beijing"

4、打印一行带有单引号的文本

[root@localhost test]# echo "We're good friends." We're good friends.

5、输出重定向到文件

[root@localhost test]# echo "I'm very good." > an.txt [root@localhost test]# cat an.txt I'm very good.

6、匹配相同的文件

[root@localhost test]# echo *.txt 1.txt 34.txt 55.txt 66.txt ab.txt an.txt etc_file.txt file2_ect.txt ini.txt num.txt

7、显示当前路径下所有的文件夹和文件

[root@localhost test]# echo * 1.txt 34.txt 55.txt 66.txt ab.txt an.txt echo_test.sh eir etc_file.txt file2_ect.txt for_loop.sh ini.txt num.txt start tay test.sh week.en yer

8、创建新行

[root@localhost test]# echo -e "welcome \nto \nbeijing" welcome to beijing

9、单词之间创建制表符空格

[root@localhost test]# echo -e "welcome\tto\tbeijing\tshanghai" welcome to beijing shanghai

10、合并新行和制表符

[root@localhost test]# echo -e "\twelcome\n\tto\n\tbeijing" welcome to beijing

11、创建垂直制表符

[root@localhost test]# echo -e "welcome\vto\vbeijing" welcome to beijing

12、合并新行和垂直制表符

[root@localhost test]# echo -e "\nwelcome\n\vto\n\vbeijing" welcome to beijing

13、使用回车选项，替换前面相同的字符

[root@localhost test]# echo -e "welcome\rto \nbeijing" to come beijing

14、截断文本

[root@localhost test]# echo -e "welcome to bei\cjing" welcome to bei[root@localhost test]#

15、退格键

[root@localhost test]# echo -e "welcome \bto \bbeijing" welcometobeijing

16、shell 脚本中 echo 命令的使用

[root@localhost test]# cat echo_test.sh #!/bin/bash # Echo Command Usage in Script os_version=$(grep -i "PRETTY_NAME" /etc/os-release | awk -F'=' '{print $2}' | sed 's/"//g') no_cpus=$(lscpu | grep '^CPU(s):' | awk -F":" '{print $2}' | sed "s/^[ \t]*//") total_mem=$(grep MemTotal /proc/meminfo | awk -F":" '{print $2}' | sed "s/^[ \t]*//") echo 'OS Version :' $os_version echo 'Number of CPUs :' $no_cpus echo 'Total Memory :' $total_mem [root@localhost test]# ./echo_test.sh OS Version : CentOS Linux 7 (Core) Number of CPUs : 8 Total Memory : 2027676 kB