Bash printing color codes literally and not in actual color

问题

For some reason my shell script stopped printing my menu in color and is actually printing the literal color code instead. Did I somehow escape the color coding?

Script

#!/bin/bash 

function showEnvironments {
echo -e "\e[38;5;81m"
echo -e "      SELECT ENVIRONMENT       "
echo -e "[1] - QA"
echo -e "[2] - PROD"
echo -e "\e[0m"
}

showEnvironments

Output

\e[38;5;81m

SELECT ENVIRONMENT

[1] - Staging

[2] - QA

\e[0m

I am using iTerm on Mac OSX and the TERM environment variable is set to xterm-256color.

回答1:

There are several apparent bugs in the implementation of echo -e in bash 3.2.x, which is what ships with Mac OS X. The documentation claims that \E (not \e) represents ESC, but neither appears to work. You can use printf instead:

printf "\e[38;5;81mfoo\e[0m\n"

or use (as you discovered) \033 to represent ESC.

Later versions of bash (definitely 4.3, possible earlier 4.x releases as well) fix this and allow either \e or \E to be used.

回答2:

Two ways to do this: reference colors directly or assign to variable to reference them easier later in the script.

cNone='\033[00m'
cRed='\033[01;31m'
cGreen='\033[01;32m'
cYellow='\033[01;33m'
cPurple='\033[01;35m'
cCyan='\033[01;36m'
cWhite='\033[01;37m'
cBold='\033[1m'
cUnderline='\033[4m'

echo -e "\033[01;31m"
echo -e "hello"
echo -e "\033[00m"

echo -e "${cGreen}"
echo -e "hello"
echo -e "${cNone}"

I hope this helps.

回答3:

I figured it out. It appears that the escape character I am using for the color code is not recognized in my terminal.

Based on http://misc.flogisoft.com/bash/tip_colors_and_formatting#colors1 valid escape codes are:

\e
\033
\x1B

When I changed my colors from \e[38;5;81m to \033[38;5;81m it started working as expected.

Thanks to everyone else for the suggestions and help!

回答4:

Two potential things to try:

run stty sane to reset the terminal settings
check the $TERM environment variable

来源：https://stackoverflow.com/questions/37115269/bash-printing-color-codes-literally-and-not-in-actual-color

标签

bash

terminal

iterm

ansi-escape