Mastering Colored Output in Shell Scripts with echo and printf

Both echo and printf can output content in shell scripts, and with the -e option they can display colored text using ANSI escape sequences.

echo -e "\033[43;35m david use echo say Hello World \033[0m 
"
printf "\033[44;36m david use printf say Hello World \033[0m 
"
echo -e "\033[47;30;5m david use echo say \033[0m Hello World 
"

The resulting output shows the specified background and foreground colors.

Format Explanation

In Bash, echo displays content, and to show colors you must use the -e option. The general format is: echo -e "\033[background;colormString\033[0m" For example: echo -e "\033[41;36m something here \033[0m" Here 41 sets the background color (red) and 36 sets the foreground color (cyan).

Notes

Background and foreground colors are separated by a semicolon ";".

The color code ends with the letter m.

Spaces before or after the string are preserved in the output.

Multiple attributes can be combined using semicolons, e.g., \033[5;4;47;30m for blink, underline, white background, black text.

Combined Commands Example

echo -e "\033[20;1H\033[1;4;32m david use echo say \033[0m Hello World 
"

This moves the cursor to line 20, column 1, then prints the text in bold, underlined, green, and finally resets attributes.

Attribute Control Codes

\033[0m  Reset all attributes
\033[1m  Bold
\033[4m  Underline
\033[5m  Blink
\033[7m  Reverse video
\033[8m  Conceal
\033[30m‑\033[37m  Set foreground color (30‑37)
\033[40m‑\033[47m  Set background color (40‑47)

Example color commands:

echo -e "\033[31m Red text \033[0m"
echo -e "\033[34m Yellow text \033[0m"
echo -e "\033[41;33m Red background, yellow text \033[0m"
echo -e "\033[41;37m Red background, white text \033[0m"

Foreground Color Range (30‑39)

echo -e "\033[30m Black \033[0m"
echo -e "\033[31m Red \033[0m"
echo -e "\033[32m Green \033[0m"
echo -e "\033[33m Yellow \033[0m"
echo -e "\033[34m Blue \033[0m"
echo -e "\033[35m Purple \033[0m"
echo -e "\033[36m Cyan \033[0m"
echo -e "\033[37m White \033[0m"
# 38: underline on default color
# 39: underline off

Background Color Range (40‑47)

40: Black
41: Dark Red
42: Green
43: Yellow
44: Blue
45: Purple
46: Dark Green
47: White
49: Default background

Cursor Position and Screen Control

\33[nA  Move cursor up n lines
\33[nB  Move cursor down n lines
\33[nC  Move cursor right n columns
\33[nD  Move cursor left n columns
\33[y;xH  Set cursor to row y, column x
\33[2J   Clear screen
\33[K    Erase to end of line
\33[s    Save cursor position
\33[u    Restore cursor position
\33[?25l Hide cursor
\33[?25h Show cursor

Predefined Color Variables

When running a Bash script repeatedly, you can define variables for color codes to simplify usage:

#! /bin/bash
RED_COLOR='\E[1;31m'
YELLOW_COLOR='\E[1;33m'
BLUE_COLOR='\E[1;34m'
RESET='\E[0m'

echo -e "${RED_COLOR}===david say red color===${RESET}"
echo -e "${YELLOW_COLOR}===david say yellow color===${RESET}"
echo -e "${BLUE_COLOR}===david say blue color===${RESET}"

Countdown Example Using Carriage Return

for i in {1..100}; do
  echo -en "\r $i%"
  sleep 1
done

Save the script as myDisplay.sh, make it executable, and run it on a Linux server to see the effects.