Nuts & Bolts of DataStage: Colourizing Unix Programs & Shell Scripts

In an ANSI compatible terminal (like xterm, rxvt, konsole ...) text may be shown in colors different from black/white. Here first the colour coding is shown for shell programming .

Each color code is present after an escape sequence. This can be given by

echo –e "\033[1m Demo Test \033[0m\n";

in this \033 is the escape and 1 represents the color code and m is the end of escape .

Color Syntax

echo "\033[COLORm Sample 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. The "m" terminates escape sequence, and text begins immediately after that.

echo "\033[40m Sample text"

Here is the color table for other colors that you can lookup and will use frequently.

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

echo -e "\033[40m Sample text"

The above define command, there was a problem ( you can see the screenshot ) , Here we set the color for the terminal not for the line. If we want to use it for specific words, we have to return in our old color coding so need to put these chunks of code where we want to end out fancy output.

Return to Normal Syntax.

echo "\033[0m"

echo -e "\033[0m"

Now you won't see anything new on the screen, as this echo statement was not passed any string to display. But it has done its job, which was to restore the normal viewing mode. Whatever yor type now will be avoid of any fancy effects.

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 Invert color coding

Blinking Characters is not working with terminal.

a) Foreground Color change Example

echo -e "\033[31m This is Red \n \033[32m This is Green \n \033[33m This is Yellow \n \033[34m This is blue \n \033[36m This is cyan \033[0m";

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

The following table summarizes these differences.

Bold off color Bold on color

0;30 Black 1;30 Dark Gray

0;31 Red 1;31 Dark Red

0;32 Green 1;32 Dark Green

0;33 Yellow 1;33 Dark 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

b) Bold Foreground Color change Example

echo -e "\033[1;31m This is Dark Red \n \033[1;32m This is Dark Green \n \033[1;33m This is Yellow \n \033[1;34m This is Dark blue \n \033[1;36m This is Dark cyan \033[0m";

c) Underlined Foreground Color change Example

echo -e "\033[4;31m This is Dark Red \n \033[4;32m This is Dark Green \n \033[4;33m This is Yellow \n \033[4;34m This is Dark blue \n \033[4;36m This is Dark cyan \033[0m";

d) Underlined Background Color change Example

echo -e "\033[4;41m This is Dark Red \n \033[4;42m This is Dark Green \n \033[4;43m This is Yellow \n \033[4;44m This is Dark blue \n \033[4;46m This is Dark cyan \033[0m";