How to use tput command in Linux.

How To Use Tput Command In Linux.

The tput command is a versatile and powerful tool in the Linux command-line arsenal. It is primarily used for manipulating and querying terminal capabilities, such as cursor control, text formatting, and color manipulation. In this article, we will explore the tput command in detail, providing explanations and practical examples to illustrate its various capabilities.

Flags

In addition to the capability names, the following strings are supported as arguments to the tput subroutine.

Exit Status

This command returns the following exit values:

Installation

The tput command is typically pre-installed on most Linux distributions, so you can start using it right away without any additional installation steps. To check if tput is available on your system, open a terminal and type:

tput --version

If you see a version number, you’re ready to proceed.

Basic Usage

1. Query Terminal Capabilities

One of the primary uses of tput is to query terminal capabilities. You can use it to retrieve information about various terminal attributes, such as the number of columns and rows in the terminal:

# Get the number of columns
tput cols

# Get the number of rows
tput lines

2. Cursor Movement

Tput allows you to move the cursor to specific positions within the terminal. For instance, to move the cursor to the top-left corner (0,0), you can use:

tput cup 0 0

3. Text Formatting

You can also use tput to apply text formatting, such as setting text colors, background colors, and text styles. Here are some examples:

# Set text color to red
tput setaf 1

# Set background color to yellow
tput setab 3

# Reset text attributes to default
tput sgr0

4. Clearing the Terminal

The tput command can be used to clear the terminal screen, making it ready for new output:

tput clear

Advanced Usage

1. Creating Colorful Output

You can use tput to create colorful and visually appealing output in your terminal scripts. For instance, to print a message with red text on a yellow background:

tput setaf 1    # Set text color to red
tput setab 3    # Set background color to yellow
echo "Hello, Linux!"
tput sgr0       # Reset text attributes

2. Animation and Dynamic Output

Tput can be used in shell scripts to create dynamic and animated terminal output. For example, you can create a simple loading animation:

#!/bin/bash

while true; do
    tput civis  # Hide cursor
    echo -n "Loading..."
    sleep 1
    tput cuu1   # Move cursor up one line
    tput el     # Clear the line
    echo -n "       "
    sleep 1
done

3. Terminal Size Handling

You can use tput to adjust your terminal output based on the terminal’s size. This is particularly useful in shell scripts that need to adapt to different screen resolutions:

# Get the number of columns
cols=$(tput cols)

# Get the number of rows
lines=$(tput lines)

echo "Terminal size: ${cols} columns x ${lines} rows"

Advanced Text Formatting

1. Text Styles

Tput allows you to apply various text styles to your output, such as bold, underline, and blink:

# Apply bold text style
tput bold

# Apply underline text style
tput smul

# Apply blink text style
tput blink

To disable these styles, you can use the sgr0 attribute to reset text attributes to their default values:

tput sgr0

2. Text Alignment

You can align text within the terminal using tput. For example, to center-align a text message within the terminal, you can calculate the center position and move the cursor accordingly:

text="Centered Text"
cols=$(tput cols)
text_length=${#text}
position=$(( (cols - text_length) / 2 ))
tput cup 0 $position
echo "$text"

Handling Keyboard Input

1. Reading User Input

Tput can also be used in conjunction with other shell commands to create interactive scripts that accept user input. For instance, you can create a simple menu system:

#!/bin/bash

clear
echo "Menu:"
echo "1. Option 1"
echo "2. Option 2"
echo "3. Quit"
echo -n "Enter your choice: "

read choice

case $choice in
    1)
        echo "You selected Option 1."
        ;;
    2)
        echo "You selected Option 2."
        ;;
    3)
        echo "Goodbye!"
        exit 0
        ;;
    *)
        echo "Invalid choice."
        ;;
esac

2. Capturing Keystrokes

You can capture specific keypresses using tput. For example, to detect the pressing of the Enter key:

#!/bin/bash

echo "Press Enter to continue..."
tput smkx  # Enable keypad transmit mode
read -s -N1 key
tput rmkx  # Disable keypad transmit mode

if [ "$key" == $'\x0a' ]; then
    echo "You pressed Enter."
else
    echo "You pressed a different key."
fi

Creating Colorful Menus

Tput can be used to create colorful menus and interactive interfaces. Here’s an example of a simple menu with colored options:

#!/bin/bash

clear
tput setaf 3  # Set text color to yellow
echo "Menu:"
tput setaf 2  # Set text color to green
echo "1. Option 1"
echo "2. Option 2"
tput setaf 1  # Set text color to red
echo "3. Quit"
tput setaf 7  # Reset text color to default
echo -n "Enter your choice: "

read choice

case $choice in
    1)
        echo "You selected Option 1."
        ;;
    2)
        echo "You selected Option 2."
        ;;
    3)
        echo "Goodbye!"
        exit 0
        ;;
    *)
        echo "Invalid choice."
        ;;
esac

Conclusion

The tput command is a versatile tool that can be used for a wide range of tasks in the Linux terminal. Whether you’re formatting text, manipulating the cursor, creating colorful output, handling user input, or designing interactive menus, tput provides the flexibility and control you need to enhance your command-line scripts and applications. By mastering its capabilities, you can create more sophisticated and user-friendly terminal-based experiences.