I'm printing a message in a Bash script, and I want to colourise a portion of it; for example,#!/bin/bashnormal='\e[0m'yellow='\e[33m'cat <<- EOF    ${yellow}Warning:${normal} This script repo is currently located in:    [ more messages... ]EOFBut when I run in the terminal (tmux inside gnome-terminal) the ANSI escape characters are just printed in \ form; for example,\e[33mWarning\e[0m This scr....If I move the portion I want to colourise into a printf command outside the here-doc, it works. For example, this works:printf ${yellow}Warning:${normal}cat <<- EOF    This script repo is currently located in:    [ more messages... ]EOFFrom man bash  Here Documents:No parameter and variable expansion, command substitution, arithmetic expansion, or pathname expansion is performed on word. If any characters in word are quoted, the delimiter is the result of quote removal on word, and the lines in the here-document are not expanded. If word is unquoted, all lines of the here-document are subjected to parameter expansion, command substitution, and arithmetic expansion. In the latter case, the character sequence \<newline> is ignored, and \ must be used to quote the characters \, $, and `.I can't work out how this would affect ANSI escape codes. Is it possible to use ANSI escape codes in a Bash here document that is catted out?
Is it possible to use ANSI color escape codes in Bash here-documents?
bash;colors;escape characters
In your script, these assignmentsnormal='\e[0m'yellow='\e[33m'put those characters literally into the variables, i.e., \e[0m, rather than the escape sequence.  You can construct an escape character using printf (or some versions of echo), e.g.,normal=$(printf '\033[0m')yellow=$(printf '\033[33m')but you would do much better to use tput, as this will work for any correctly set up terminal:normal=$(tput sgr0)yellow=$(tput setaf 3)Looking at your example, it seems that the version of printf you are using treats \e as the escape character (which may work on your system, but is not generally portable to other systems).  To see this, tryyellow='\e[33m'printf 'Yellow:%s\n' $yellowand you would see the literal characters:Yellow:\e[33mrather than the escape sequence.  Putting those in the printf format tells printf to interpret them (if it can).Further reading:tput,  reset  -  initialize  a  terminal or query terminfo databaseprintf - write formatted output (POSIX)