Control terminal appearance with tput

To control things like text color and cursor position in a terminal emulator, you need to use ANSI escape codes. These are mostly-inscrutable character sequences that can be printed to perform specific actions.

For example, here’s how to print some text in red followed by some text in black:

echo "\033[0;31m" red text "\033[0;30m" black text

The strings \033[0;31m and \033[0;30m are the escape code for red and black foregrounds, respectively.

One problem is that not all terminals support all codes. There’s a database called terminfo that describes the capabilities of each terminal, determined by an identifier (you can see which identifier your terminal is using by running echo $TERM). Each terminal’s capabilities are identified by “capnames”.

Luckily, there’s a command to handle all this called tput. Here’s how to use it to print the same text as the previous example:

echo "$(tput setaf 1)" red text "$(tput setaf 0)" black text

setaf is the capname for changing the foreground color, and 1 and 0 are the standard color codes for red and black. I’m not sure whether there’s a list mapping human-readable color names to numbers, but you can easily fix that with environment variables:

RED=1
BLACK=0
echo "$(tput setaf $RED)" red text "$(tput setaf $BLACK)" black text

tput can do more than set colors. For example, you might run tput civis and tput cnorm to hide the cursor during a progress animation, then show it again after:

# hide the cursor
tput civis

# fancy progress animation code goes here

# show the cursor
tput cnorm