We can use ANSI color codes to print text in different color and text styles.
To prettify a string with a color and text styles ie. bold, underline, we need to enclose and tag the affected string with a set of ANSI code. This means we need to escape with a value of 27 (33 in octal or 1B in hex) followed by an ANSI code.
In other words, to print text "Hello World" in red color. We do the following:
$ # \033 = Escape with octal value of 33 to tell the shell to expect a ANSI code.
$ # [Xm = Substitute X with an ANSI code (decimal) enclosed in [m.
$ echo -e "\033[31mHello World\033[0m"Once we are done with tagging the string with the ANSI codes, we reset back to the plain color and style using \033[0m.
Be sure to add the -e parameter to the echo command.
We can also use escapes \x1b and \e in place of \033. In other words, the following will produce the same outputs.
$ echo -e "\033[31mHello World\033[0m"
$ echo -e "\x1b[31mHello World\x1b[0m"
$ echo -e "\e[31mHello World\e[0m"See ansi-code.sh for details.
We can also use tput to print the text in color.
bold=$(tput bold)
reset=$(tput sgr0)
red=$(tput setaf 1)
# No -e needed when using tput
echo "${red}${bold}Hello World${reset}"See tput.sh for details.
| ANSI Code | tput Command | Effect |
|---|---|---|
| 0 | sgr0 | Reset |
| 1 | bold | Bold: on |
| 2 | dim | Faint: on |
| 3 | Italic: on | |
| 4 | smul | Underline: on |
| 5 | Slow blink: on | |
| 6 | blink | Fast blink: on |
| 7 | rev | Reverse video: on |
| 8 | invis | Erase: on |
| 9 | Strikethrough: on | |
| 21 | Double underline: on | |
| 22 | Bold: off | |
| 23 | Italic: off | |
| 24 | emul | Underline: off |
| 25 | Slow blink: off | |
| 26 | Fast blink: off | |
| 27 | Reverse video: off | |
| 28 | Erase: off | |
| 29 | Strikethrough: off | |
| 30 | setaf 0 | Foreground: black |
| 31 | setaf 1 | Foreground: red |
| 32 | setaf 2 | Foreground: green |
| 33 | setaf 3 | Foreground: yellow |
| 34 | setaf 4 | Foreground: blue |
| 35 | setaf 5 | Foreground: magenta |
| 36 | setaf 6 | Foreground: cyan |
| 37 | setaf 7 | Foreground: white |
| 39 | setaf 9 | Foreground: reset |
| 40 | setab 0 | Background: black |
| 41 | setab 1 | Background: red |
| 42 | setab 2 | Background: green |
| 43 | setab 3 | Background: yellow |
| 44 | setab 4 | Background: blue |
| 45 | setab 5 | Background: magenta |
| 46 | setab 6 | Background: cyan |
| 47 | setab 7 | Background: white |
| 49 | setab 9 | Background: reset |