Linux echo text processing command usage and examples

[root@localhost ~]$ echo # Output a blank line[root@localhost ~]$ echo "hello world" # Output the specified string[root@localhost ~]$ echo $HOSTNAME # Output the value corresponding to the variable name[root@localhost ~]$ echo "hello world" > 1.txt # Output the string to the specified file[root@localhost ~]$ echo `date` # Output the execution result of the command

[root@localhost ~]$ echo -n "hello world" # -n does not output a newline at the end. By default, a newline will be output at the end. hello world[root@localhost ~]$

[root@localhost ~]$ echo -e "hello\nworld" # -e is used to enable backslash escape, such as \n will be converted to newline hello
world

[root@localhost ~]$ echo -E "hello\nworld" # -E is used to disable backslash escape, which is disabled by default.

[root@localhost ~]$ echo -e "hello \\ world" # \\ is used to output backslash hello \ world

[root@localhost ~]$ echo -e "\a" # \a is used for ringing, a ringing sound[root@localhost ~]$ echo -e "hello\bworld" # \b is used for backspace, reference: https://blog.csdn.net/lucosax/article/details/34963593
hellworld

[root@localhost ~]$ echo -e "hello \c world" # After using this escape character, the characters after \c will no longer output hello 

[root@localhost ~]$ echo -e "\e[32;1m hello world \e[35;1m" # \e is used to control the font and background color hello world 

[root@localhost ~]$ echo -e "hello \f hello \f hello" # \f new line, and the cursor stops at the original place after the new line hello 
    hello
       hello

[root@localhost ~]$ echo -e "hello\nworld" # \n newline character hello
world

[root@localhost ~]$ echo -e "hello\rworld" # \r is used to move the cursor to the beginning of the line, which is equivalent to deleting the characters before \r and only outputting the characters after \r world

[root@localhost ~]$ echo -e "hello\tworld" # \t Tab character, equivalent to the Tab key on the keyboard hello world

[root@localhost ~]$ echo -e "hello\vworld" # \v vertical tab hello
   world

// Output colored font echo -e "\033[30m black font\033[0m"
echo -e "\033[31m red word\033[0m"
echo -e "\033[32m green word\033[0m"
echo -e "\033[33m yellow text\033[0m"
echo -e "\033[34m blue words\033[0m"
echo -e "\033[35m purple text\033[0m"
echo -e "\033[36m sky blue word\033[0m"
echo -e "\033[37m white word\033[0m"

// Output font with background color echo -e "\033[40;37m black background white text\033[0m"
echo -e "\033[41;37m Red background with white characters\033[0m"
echo -e "\033[42;37m green background with white text\033[0m"
echo -e "\033[43;37m yellow background white text\033[0m"
echo -e "\033[44;37m blue background white text\033[0m"
echo -e "\033[45;37m purple background white text\033[0m"
echo -e "\033[46;37m sky blue background with white text\033[0m"
echo -e "\033[47;30m Black text on white background\033[0m"

//Other properties\33[0m Turn off all properties\33[1m Set high brightness\33[4m Underline\33[5m Blink\33[7m Reverse display\33[8m Hide\33[30m — \33[37m Set foreground color\33[40m — \33[47m Set background color\33[nA Move cursor up n lines\33[nB Move cursor down n lines\33[nC Move cursor right n lines\33[nD Move cursor left n lines\33[y;xH Set cursor position\33[2J Clear screen\33[K Clear the content from cursor to the end of the line\33[s Save cursor position\33[u Restore cursor position\33[?25l Hide cursor\33[?25h Show cursor

[root@aliyun-hk1 linux-shell-test]# echo hello\nworld
hellonworld
[root@aliyun-hk1 linux-shell-test]# echo 'hello\nworld'
hello\nworld
[root@aliyun-hk1 linux-shell-test]# echo hello world
hello world
[root@aliyun-hk1 linux-shell-test]#

[root@aliyun-hk1 linux-shell-test]# echo -n hello world
hello world[root@aliyun-hk1 linux-shell-test]# echo hello world
hello world

[root@aliyun-hk1 linux-shell-test]# echo -e 'hello\nworld'
hello
world
[root@aliyun-hk1 linux-shell-test]# echo -e 'hello\tworld'
hello world

[root@aliyun-hk1 linux-shell-test]# echo -E 'hello\nworld'
hello\nworld
[root@aliyun-hk1 linux-shell-test]# echo -E 'hello\tworld'
hello_tworld

[root@aliyun-hk1 linux-shell-test]# echo hello
hello
[root@aliyun-hk1 linux-shell-test]# cat hello
cat: hello: No such file or directory
[root@aliyun-hk1 linux-shell-test]# echo /etc/hostname
/etc/hostname
[root@aliyun-hk1 linux-shell-test]# cat /etc/hostname
aliyun-hk1
[root@aliyun-hk1 linux-shell-test]# echo hello|cat
hello
[root@aliyun-hk1 linux-shell-test]#

[root@aliyun-hk1 linux-shell-test]# echo -en 'name phone addr\nrobin 13712345678 CN\ntom 13812345678 HK\n'
name phone addr
robin 13712345678 CN
tom 13812345678 HK
[root@aliyun-hk1 linux-shell-test]# echo -en 'name phone addr\nrobin 13712345678 CN\ntom 13812345678 HK\n'|awk 'NR>1 {print $1}'
robin
tom
- name: show the items from DB
   debug:
    msg: "{{ item }}"
   with_lines: "echo -en 'name phone addr\nrobin 13712345678 CN\ntom 13812345678 HK\n'|awk 'NR>1 {print $1}'
​
TASK [show the items from DB] ******************************************************************************************************************************************************************************************************************************** ok: [localhost] => (item=robin) => {
  "msg": "robin"
}
ok: [localhost] => (item=tom) => {
  "msg": "tom"
}

[root@aliyun-hk1 ansible-test]# echo -en 'name phone addr\nrobin 13712345678 CN\ntom 13812345678 HK\n'|awk 'NR>1 {print $1}' > DataFromDB1.txt
[root@aliyun-hk1 ansible-test]# cat DataFromDB1.txt
robin
tom
[root@aliyun-hk1 ansible-test]#