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Terminal control using ANSI escape sequences

Term::ANSIScreen - Terminal control using ANSI escape sequences


Term::ANSIScreen - Terminal control using ANSI escape sequences


This document describes version 1.41 of Term::ANSIScreen, released March 22, 2004.


    # qw/:color/ is exported by default, i.e. color() & colored()

    use Term::ANSIScreen qw/:color :cursor :screen :keyboard/;

    print setmode(1), setkey('a','b');

    print "40x25 mode now, with 'a' mapped to 'b'.";

    <STDIN>; resetkey; setmode 3; cls;

    locate 1, 1; print "@ This is (1,1)", savepos;

    print locate(24,60), "@ This is (24,60)"; loadpos;

    print down(2), clline, "@ This is (3,15)\n";

    setscroll 1, 20;

    color 'black on white'; clline;

    print "This line is black on white.\n";

    print color 'reset'; print "This text is normal.\n";

    print colored ("This text is bold blue.\n", 'bold blue');

    print "This text is normal.\n";

    print colored ['bold blue'], "This text is bold blue.\n";

    print "This text is normal.\n";

    use Term::ANSIScreen qw/:constants/; # constants mode

    print BLUE ON GREEN . "Blue on green.\n";

    $Term::ANSIScreen::AUTORESET = 1;

    print BOLD GREEN . ON_BLUE "Bold green on blue.", CLEAR;

    print "\nThis text is normal.\n";

    # Win32::Console emulation mode

    # this returns a Win32::Console object on a Win32 platform

    my $console = Term::ANSIScreen->new;

    $console->Cls;      # also works on non-Win32 platform


Term::ANSIScreen is a superset of Term::ANSIColor (as of version 1.04 of that module). In addition to color-sequence generating subroutines exported by :color and :constants, this module also features :cursor for cursor positioning, :screen for screen control, as well as :keyboard for key mapping.


  • All subroutines in Term::ANSIScreen will print its return value if called under a void context.

  • The cursor position, current color, screen mode and keyboard mappings affected by Term::ANSIScreen will last after the program terminates. You might want to reset them before the end of your program.


Win32::Console emulation mode

When used in a object-oriented fashion, Term::ANSIScreen acts as a Win32::Console clone:

    use Term::ANSIScreen;

    my $console = Term::ANSIScreen->new;

    $console->Cls();            # unbuffered

    $console->Cursor(0, 0);     # same as locate(1, 1)

    $console->Display();        # really a no-op

On the Win32 platform, the new constructor simply returns a geniune Win32::Console object, if that module exists in the system.

This feature is intended for people who has to port Win32 console applications to other platforms, or to write cross-platform application that needs terminal controls.

The :color function set (exported by default)

Term::ANSIScreen recognizes (case-insensitively) following color attributes: clear, reset, bold, underline, underscore, blink, reverse, concealed, black, red, green, yellow, blue, magenta, on_black, on_red, on_green, on_yellow, on_blue, on_magenta, on_cyan, and on_white.

The color alone sets the foreground color, and on_color sets the background color. You may also use on_color without the underscore, e.g. ``black on white''.

color LIST
Takes any number of strings as arguments and considers them to be space-separated lists of attributes. It then forms and returns the escape sequence to set those attributes.

colored EXPR, LIST
Takes a scalar as the first argument and any number of attribute strings as the second argument, then returns the scalar wrapped in escape codes so that the attributes will be set as requested before the string and reset to normal after the string.

Alternately, you can pass a reference to an array as the first argument, and then the contents of that array will be taken as attributes and color codes and the remainder of the arguments as text to colorize.

Normally, this function just puts attribute codes at the beginning and end of the string, but if you set $Term::ANSIScreen::EACHLINE to some string, that string will be considered the line delimiter and the attribute will be set at the beginning of each line of the passed string and reset at the end of each line. This is often desirable if the output is being sent to a program like a pager, which can be confused by attributes that span lines.

Normally you'll want to set $Term::ANSIScreen::EACHLINE to "\n" to use this feature.

The :constants function set

If you import :constants you can use the constants CLEAR, RESET, BOLD, UNDERLINE, UNDERSCORE, BLINK, REVERSE, CONCEALED, BLACK, RED, GREEN, YELLOW, BLUE, MAGENTA, ON_BLACK, ON_RED, ON_GREEN, ON_YELLOW, ON_BLUE, ON_MAGENTA, ON_CYAN, and ON_WHITE directly. These are the same as color('attribute') and can be used if you prefer typing:

    print BOLD BLUE ON_WHITE "Text\n", RESET;

    print BOLD BLUE ON WHITE "Text\n", RESET; # _ is optional

to print colored (``Text\n'', 'bold blue on_white');

When using the constants, if you don't want to have to remember to add the , RESET at the end of each print line, you can set $Term::ANSIScreen::AUTORESET to a true value. Then, the display mode will automatically be reset if there is no comma after the constant. In other words, with that variable set:

    print BOLD BLUE "Text\n";

will reset the display mode afterwards, whereas:

    print BOLD, BLUE, "Text\n";

will not.

The :cursor function set

locate [EXPR, EXPR]
Sets the cursor position. The first argument is its row number, and the second one its column number. If omitted, the cursor will be located at (1,1).

up [EXPR]
down [EXPR]
left [EXPR]
right [EXPR]
Moves the cursor toward any direction for EXPR characters. If omitted, EXPR is 1.

Saves/restores the current cursor position.

The :screen function set

Clears the screen with the current background color, and set cursor to (1,1).

Clears the current row with the current background color, and set cursor to the 1st column.

Clears everything above the cursor.

Clears everything below the cursor.

setmode EXPR
Sets the screen mode to EXPR. Under DOS, ANSI.SYS recognizes following values:

     0:  40 x  25 x   2 (text)   1:  40 x  25 x 16 (text)

     2:  80 x  25 x   2 (text)   3:  80 x  25 x 16 (text)

     4: 320 x 200 x   4          5: 320 x 200 x  2

     6: 640 x 200 x   2          7: Enables line wrapping

    13: 320 x 200 x   4         14: 640 x 200 x 16

    15: 640 x 350 x   2         16: 640 x 350 x 16

    17: 640 x 480 x   2         18: 640 x 480 x 16

    19: 320 x 200 x 256

Enables/disables the line-wraping mode.

setscroll EXPR, EXPR
Causes scrolling to occur only on the lines numbered between the first and second arguments, inclusive.

The :keyboard function set

setkey EXPR, EXPR
Takes a scalar representing a single keystroke as the first argument (either a character or an escape sequence in the form of "num1;num2"), and maps it to a string defined by the second argument. Afterwards, when the user presses the mapped key, the string will get outputed instead.

resetkey [LIST]
Resets each keys in the argument list to its original mapping. If called without an argument, resets all previously mapped keys.


Invalid attribute name %s
You passed an invalid attribute name to either color() or colored().

Identifier %s used only once: possible typo
You probably mistyped a constant color name such as:

    print FOOBAR "This text is color FOOBAR\n";

It's probably better to always use commas after constant names in order to force the next error.

No comma allowed after filehandle
You probably mistyped a constant color name such as:

    print FOOBAR, "This text is color FOOBAR\n";

Generating this fatal compile error is one of the main advantages of using the constants interface, since you'll immediately know if you mistype a color name.

Bareword %s not allowed while ``strict subs'' in use
You probably mistyped a constant color name such as:

    $Foobar = FOOBAR . "This line should be blue\n";


    @Foobar = FOOBAR, "This line should be blue\n";

This will only show up under use strict (another good reason to run under use strict).


the Term::ANSIColor manpage, the Win32::Console manpage


Autrijus Tang <>


Copyright 2001, 2003, 2003, 2004 by Autrijus Tang <>.

Based on works of Zenin (, Russ Allbery (

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.