Shell Colors: colorizing shell scripts

Shell Colors: colorizing shell scripts


Shell scripts commonly used ANSI escape codes for color output.
Following table shows Numbers representing colors in Escape Sequences.

Color	Foreground	Background
Black	30	40
Red	31	41
Green	32	42
Yellow	33	43
Blue	34	44
Magenta	35	45
Cyan	36	46
White	37	47

Use the following template for writing colored text.

echo -e "\033[COLORm Sample text"

The "\033[" begins the escape sequence.You can also use "\e[" instead
of "\033[". COLOR specifies a foreground color, according to the table
above.The "m" terminates escape sequence, and text begins immediately
after that.

Note: With an echo, the -e option enables the escape sequences.You can
also use printf instead of echo. 

printf "\e[COLORm sample text\n"

To print Green text

echo -e "\033[32m Hello World"
             or
printf "\e[32m Hello World"

To return to the plain, normal mode, we have yet another sequence.

echo -e "\033[0m"

The following table summarizes numbers representing text attributes
in Escape Sequences.




ANSI CODE
Meaning
0
Normal Characters
1
Bold Characters
4
Underlined Characters
5
Blinking Characters
7
Reverse video Characters




Note: Blink attribute doesn't work in any terminal emulator, but it
will work on the console.
 

echo -e "\033[COLOR1;COLOR2m sample text\033[0m"

There are some differences between colors when combining colors with
bold text attribute.

The following table summarises these differences.


Bold off
color
Bold on
color
0;30
Balck
1;30
Dark Gray
0;31
Red
1;31
Dark Red
0;32
Green
1;32
Dark Green
0;33
Brown
1;33
Yellow
0;34
Blue
1;34
Dark Blue
0;35
Magenta
1;35
Dark Magenta
0;36
Cyan
1;30
Dark Cyan
0;37
Light Gray
1;30
White

There are some differences between colors when combining colors with
bold text attribute.

The following table summarises these differences.


Bold off
color
Bold on
color
0;30
Balck
1;30
Dark Gray
0;31
Red
1;31
Dark Red
0;32
Green
1;32
Dark Green
0;33
Brown
1;33
Yellow
0;34
Blue
1;34
Dark Blue
0;35
Magenta
1;35
Dark Magenta
0;36
Cyan
1;30
Dark Cyan
0;37
Light Gray
1;30
White

The following shell script prints all the colors and codes on the
screen.

#!/bin/bash
# This script echoes colors and codes

echo -e "\n\033[4;31mLight Colors\033[0m  \t\t\033[1;4;31mDark Colors\033[0m"

echo -e "\e[0;30;47m Black    \e[0m 0;30m \t\e[1;30;40m Dark Gray  \e[0m 1;30m"
echo -e "\e[0;31;47m Red      \e[0m 0;31m \t\e[1;31;40m Dark Red   \e[0m 1;31m"
echo -e "\e[0;32;47m Green    \e[0m 0;32m \t\e[1;32;40m Dark Green \e[0m 1;32m"
echo -e "\e[0;33;47m Brown    \e[0m 0;33m \t\e[1;33;40m Yellow     \e[0m 1;33m"
echo -e "\e[0;34;47m Blue     \e[0m 0;34m \t\e[1;34;40m Dark Blue  \e[0m 1;34m"
echo -e "\e[0;35;47m Magenta  \e[0m 0;35m \t\e[1;35;40m DarkMagenta\e[0m 1;35m"
echo -e "\e[0;36;47m Cyan     \e[0m 0;36m \t\e[1;36;40m Dark Cyan  \e[0m 1;36m"
echo -e "\e[0;37;47m LightGray\e[0m 0;37m \t\e[1;37;40m White      \e[0m 1;37m"

OUTPUT:



Some examples:
Block background and white text

echo -e "\033[40;37m Hello World\033[0m"

Reverse video text attribute option interchanges fg and bg colors.
Bellow statement prints block on white

echo -e "\033[40;37;7m Hello World\033[0m"

echo -e "\033[33;44m Yellow text on blue background\033[0m"
echo -e "\033[1;33;44m Bold yellow text on blue background\033[0m"