echo command
Function: Display character (trailing line wrapping function)
Syntax: Echo [-nee][string]
Description: Echo will send the input string to standard output. The output string is separated by a white space character, and a newline number is added at the end
-n is not at the end of the character wrap-E If the following character appears in the string, it is handled in particular, not as a generic literal output.
\a warns; echo -e " \a " \b backspace; echo -e " abdc\bxx " \c does not produce further output (characters after \c or \ X Special symbols are not recognized); \ 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 (the first letter is overwritten); echo -e " abdc\rxx " \t insert tab;\\ insert \ character; \0nnn insert nnn (octal) represents ASCII character echo -E \0101 "
echo -e " \033[43;31mred color\033[0m " 30 -37 foreground color 40 - Span style= "COLOR: #800080" >47 background color
Print the text of the effect with the echo command:
Span style= "font-family: italics; Font-size:18px "> \e[nm n is a numeric code, multiple with"; " Separate [33;36;5m Red Hat [0m
text color code: RESET = 0, black = 30, red = 31, green = 32, yellow = 33, Blue = 34, magenta =35, cyan = 36, white =37
background color code: RESET = 0, black = 40, red = 41, green = 42, yellow = 43, blue = 44, magenta =45, cyan = 46, white =47
Other numeric parameters: 0 Close All properties, 1 Set high brightness (bold), 4 underscore, 5 blinking, 7 Echo, 8 blanking
\xhh Insert the ASCII character represented by HH (hex) /span> 
Echo " $VAR _name " : variable is replaced, double quote table weak Reference command is not recognized, variable recognition Echo ' $VAR _name ' : Variables are not replaced, strong references do not recognize echo 'echo $UID ': Command substitution command variable what is "equivalent to $ ()
Linux Basic Command-echo