What is the terminal command to take a screenshot?

You can use the import tool available in the ImageMagick package (you need to install this if it's not already available on your system).

Then run the following command in a shell:

import screenshot.png

and select the window you want to capture or select a region by pressing the left mouse button and dragging.

import is a actually a very powerful command which can be used in many ways to capture the screen. For example, to capture the entire screen after some delay and resize it, use the following command:

import -window root -resize 400x300 -delay 200 screenshot.png

To see all the available options with the import command, go to ImageMagick’s website.

Another way to take a screenshot from the terminal is with scrot.

To install scrot run:

sudo apt-get install scrot

To take a screenshot in Linux from the terminal with scrot run:

scrot MyScreenshot.png

Some more options with scrot are here:

scrot -b -d 5 '%Y:%m:%d:%H:%M:%S.png' -e 'mv $f ~/Desktop/'

In this example:

• -b specifies that the screenshot should include the window borders.
• -d specifies a delay of five seconds.
• '%Y:%m:%d:%H:%M:%S.png' will save the screenshot with a name based on the current date and time with the format specified, .png in this case.
• -e 'mv $f ~/Desktop/' tells scrot to save the screenshot on the Desktop.

Open a terminal by pressing Ctrl+Alt+T and run:

gnome-screenshot

Use gnome-screenshot -d xx to delay the action. For example, to delay the screenshot action by 10 s:

gnome-screenshot -d 10

or

sleep 10;gnome-screenshot

You can use shutter program to take screenshot from terminal.Run the below commands in terminal to install shutter,

sudo add-apt-repository ppa:shutter/ppa
sudo apt-get update
sudo apt-get install shutter

To take a screenshot of active window,

shutter -a -o shot.png -e

To take a screenshot of whole display,

shutter -f -o shot.png -e

The screenshots taken are stored in the home directory.

For more options run shutter --help command,

Usage:
    shutter [options]

Options:
    Example 1
            shutter -a -p=myprofile --min_at_startup

    Example 2
            shutter -s=100,100,300,300 -e

    Example 3
            shutter --window=.*firefox.*

    Example 4
            shutter --web=http://shutter-project.org/ -e

  Capture Mode Options:
    -s, --select=[X,Y,WIDTH,HEIGHT]
            Capture an area of the screen. Providing X,Y,WIDTH,HEIGHT is
            optional.

    -f, --full
            Capture the entire screen.

    -w, --window=[NAME_PATTERN]
            Select a window to capture. Providing a NAME_PATTERN (Perl-style
            regex) ist optional.

    -a, --active
            Capture the current active window.

    --section
            Capture a section. You will be able to select any child window
            by moving the mouse over it.

    -m, --menu
            Capture a menu.

    -t, --tooltip
            Capture a tooltip.

    --web=[URL]
            Capture a webpage. Providing an URL ist optional.

    -r, --redo
            Redo last screenshot.

  Settings Options:
    -p, --profile=NAME
            Load a specific profile on startup.

    -o, --output=FILENAME
            Specify a filename to save the screenshot to (overwrites any
            profile-related setting).

            Supported image formats: You can save to any popular image
            format (e.g. jpeg, png, gif, bmp). Additionally it is possible
            to save to pdf, ps or svg.

            Please note: There are several wildcards available, like

             %Y = year
             %m = month
             %d = day
             %T = time
             $w = width
             $h = height
             $name = multi-purpose (e.g. window title)
             $nb_name = like $name but without blanks in resulting strings
             $profile = name of current profile
             $R = random char (e.g. $RRRR = ag4r)
             %NN = counter

            The string is interpretted by strftime. See "man strftime" for
            more examples.

            As an example: shutter -f -e -o './%y-%m-%d_$w_$h.png' would
            create a file named '11-10-28_1280_800.png' in the current
            directory.

  Application Options:
    -h, --help
            Prints a brief help message and exits.

    -v, --version
            Prints version information.

    -d, --debug
            Prints a lot of debugging information to STDOUT.

    --clear_cache
            Clears cache, e.g. installed plugins, at startup.

    --min_at_startup
            Starts Shutter minimized to tray.

    --disable_systray
            Disables systray icon.

    -e, --exit_after_capture
            Exit after the first capture has been made. This is useful when
            using Shutter in scripts.