I am trying to make a function in bash that gets a parameter and based on that parameter it colors the text. Say colorText RED will color my text red. This is what I wrote so far but it says ./colorText: line 10: ${$1}dad: bad substitution
#!/bin/bash
RED="\033[31m"
GREEN="\033[0;32m"
YELLOW="\033[0;33m"
NC="\033[0m"
colorText () {
echo $1
echo -e "${$1}dad"
}
colorText $1
The last $1 is because I want to use the script file from my terminal.
Try this:
$ cat tst.sh
#!/usr/bin/env bash
declare -A c
c["RED"]='31'
c["GREEN"]='32'
c["YELLOW"]='33'
c["BLACK"]='0'
colorText () {
printf '%s\n' "$1"
printf '\e[%sm%s\e[0m\n' "${c[$1]}" 'dad'
}
colorText "$1"
See also:
So check if $1 is equal to RED, if it is, output $RED, repeat for every color. You can just switch on the color number.
case "$1" in
RED) n=31; ;;
GREEN) n=32; ;;
YELLOW) n=33; ;;
esac
echo -e "\033[${n}m"
A couple small tweaks to OP's current code:
colorText () {
local -n color="${1}" # define local variable as nameref
echo -e "${color}dad${NC}" # add ${NC} to turn off colorization
}
Taking for a test drive:
RED="\033[31m"
GREEN="\033[0;32m"
YELLOW="\033[0;33m"
NC="\033[0m"
colorText RED
colorText GREEN
colorText YELLOW
colorText BLUE # BLUE is undefined so there should be no color applied
This generates:
If you already created color variables then just use them as is, like this:
RED="\033[31m"
GREEN="\033[0;32m"
YELLOW="\033[0;33m"
NC="\033[0m"
colorText(){ echo -e "${1}dad"; }
colorText "$RED"
IMHO function is redundant here, just use echo -e or printf with color vars:
printf "${RED}dad${NC}"
ps. check out this