Term::ANSIColor(3pm) Perl Programmers Reference Guide Term::ANSIColor(3pm)
NAME
Term::ANSIColor - Color screen output using ANSI escape sequences
SYNOPSIS
use Term::ANSIColor;
print color('bold blue');
print "This text is bold blue.\n";
print color('reset');
print "This text is normal.\n";
print colored("Yellow on magenta.", 'yellow on_magenta'), "\n";
print "This text is normal.\n";
print colored(['yellow on_magenta'], 'Yellow on magenta.', "\n");
print colored(['red on_bright_yellow'], 'Red on bright yellow.', "\n");
print colored(['bright_red on_black'], 'Bright red on black.', "\n");
print "\n";
# Map escape sequences back to color names.
use Term::ANSIColor 1.04 qw(uncolor);
my @names = uncolor('01;31');
print join(q{ }, @names), "\n";
# Strip all color escape sequences.
use Term::ANSIColor 2.01 qw(colorstrip);
print colorstrip("\e[1mThis is bold\e[0m"), "\n";
# Determine whether a color is valid.
use Term::ANSIColor 2.02 qw(colorvalid);
my $valid = colorvalid('blue bold', 'on_magenta');
print "Color string is ", $valid ? "valid\n" : "invalid\n";
# Create new aliases for colors.
use Term::ANSIColor 4.00 qw(coloralias);
coloralias('alert', 'red');
print "Alert is ", coloralias('alert'), "\n";
print colored("This is in red.", 'alert'), "\n";
use Term::ANSIColor qw(:constants);
print BOLD, BLUE, "This text is in bold blue.\n", RESET;
use Term::ANSIColor qw(:constants);
{
local $Term::ANSIColor::AUTORESET = 1;
print BOLD BLUE "This text is in bold blue.\n";
print "This text is normal.\n";
}
use Term::ANSIColor 2.00 qw(:pushpop);
print PUSHCOLOR RED ON_GREEN "This text is red on green.\n";
print PUSHCOLOR BRIGHT_BLUE "This text is bright blue on green.\n";
print RESET BRIGHT_BLUE "This text is just bright blue.\n";
print POPCOLOR "Back to red on green.\n";
print LOCALCOLOR GREEN ON_BLUE "This text is green on blue.\n";
print "This text is red on green.\n";
{
local $Term::ANSIColor::AUTOLOCAL = 1;
print ON_BLUE "This text is red on blue.\n";
print "This text is red on green.\n";
}
print POPCOLOR "Back to whatever we started as.\n";
DESCRIPTION
This module has two interfaces, one through color() and colored() and
the other through constants. It also offers the utility functions
uncolor(), colorstrip(), colorvalid(), and coloralias(), which have to
be explicitly imported to be used (see "SYNOPSIS").
If you are using Term::ANSIColor in a console command, consider
supporting the CLICOLOR standard. See "Supporting CLICOLOR" for more
information.
See "COMPATIBILITY" for the versions of Term::ANSIColor that introduced
particular features and the versions of Perl that included them.
Supported Colors
Terminal emulators that support color divide into four types: ones that
support only eight colors, ones that support sixteen, ones that support
256, and ones that support 24-bit color. This module provides the ANSI
escape codes for all of them. These colors are referred to as ANSI
colors 0 through 7 (normal), 8 through 15 (16-color), 16 through 255
(256-color), and true color (called direct-color by xterm).
Unfortunately, interpretation of colors 0 through 7 often depends on
whether the emulator supports eight colors or sixteen colors.
Emulators that only support eight colors (such as the Linux console)
will display colors 0 through 7 with normal brightness and ignore
colors 8 through 15, treating them the same as white. Emulators that
support 16 colors, such as gnome-terminal, normally display colors 0
through 7 as dim or darker versions and colors 8 through 15 as normal
brightness. On such emulators, the "normal" white (color 7) usually is
shown as pale grey, requiring bright white (15) to be used to get a
real white color. Bright black usually is a dark grey color, although
some terminals display it as pure black. Some sixteen-color terminal
emulators also treat normal yellow (color 3) as orange or brown, and
bright yellow (color 11) as yellow.
Following the normal convention of sixteen-color emulators, this module
provides a pair of attributes for each color. For every normal color
(0 through 7), the corresponding bright color (8 through 15) is
obtained by prepending the string "bright_" to the normal color name.
For example, "red" is color 1 and "bright_red" is color 9. The same
applies for background colors: "on_red" is the normal color and
"on_bright_red" is the bright color. Capitalize these strings for the
constant interface.
There is unfortunately no way to know whether the current emulator
supports more than eight colors, which makes the choice of colors
difficult. The most conservative choice is to use only the regular
colors, which are at least displayed on all emulators. However, they
will appear dark in sixteen-color terminal emulators, including most
common emulators in UNIX X environments. If you know the display is
one of those emulators, you may wish to use the bright variants
instead. Even better, offer the user a way to configure the colors for
a given application to fit their terminal emulator.
For 256-color emulators, this module additionally provides "ansi0"
through "ansi15", which are the same as colors 0 through 15 in sixteen-
color emulators but use the 256-color escape syntax, "grey0" through
"grey23" ranging from nearly black to nearly white, and a set of RGB
colors. The RGB colors are of the form "rgbRGB" where R, G, and B are
numbers from 0 to 5 giving the intensity of red, green, and blue. The
grey and RGB colors are also available as "ansi16" through "ansi255" if
you want simple names for all 256 colors. "on_" variants of all of
these colors are also provided. These colors may be ignored completely
on non-256-color terminals or may be misinterpreted and produce random
behavior. Additional attributes such as blink, italic, or bold may not
work with the 256-color palette.
For true color emulators, this module supports attributes of the form
"rNNNgNNNbNNN" and "on_rNNNgNNNbNNN" for all values of NNN between 0
and 255. These represent foreground and background colors,
respectively, with the RGB values given by the NNN numbers. These
colors may be ignored completely on non-true-color terminals or may be
misinterpreted and produce random behavior.
Function Interface
The function interface uses attribute strings to describe the colors
and text attributes to assign to text. The recognized non-color
attributes are clear, reset, bold, dark, faint, italic, underline,
underscore, blink, reverse, and concealed. Clear and reset (reset to
default attributes), dark and faint (dim and saturated), and underline
and underscore are equivalent, so use whichever is the most intuitive
to you.
Note that not all attributes are supported by all terminal types, and
some terminals may not support any of these sequences. Dark and faint,
italic, blink, and concealed in particular are frequently not
implemented.
The recognized normal foreground color attributes (colors 0 to 7) are:
black red green yellow blue magenta cyan white
The corresponding bright foreground color attributes (colors 8 to 15)
are:
bright_black bright_red bright_green bright_yellow
bright_blue bright_magenta bright_cyan bright_white
The recognized normal background color attributes (colors 0 to 7) are:
on_black on_red on_green on yellow
on_blue on_magenta on_cyan on_white
The recognized bright background color attributes (colors 8 to 15) are:
on_bright_black on_bright_red on_bright_green on_bright_yellow
on_bright_blue on_bright_magenta on_bright_cyan on_bright_white
For 256-color terminals, the recognized foreground colors are:
ansi0 .. ansi255
grey0 .. grey23
plus "rgbRGB" for R, G, and B values from 0 to 5, such as "rgb000" or
"rgb515". Similarly, the recognized background colors are:
on_ansi0 .. on_ansi255
on_grey0 .. on_grey23
plus "on_rgbRGB" for R, G, and B values from 0 to 5.
For true color terminals, the recognized foreground colors are
"rRRRgGGGbBBB" for RRR, GGG, and BBB values between 0 and 255.
Similarly, the recognized background colors are "on_rRRRgGGGbBBB" for
RRR, GGG, and BBB values between 0 and 255.
For any of the above listed attributes, case is not significant.
Attributes, once set, last until they are unset (by printing the
attribute "clear" or "reset"). Be careful to do this, or otherwise
your attribute will last after your script is done running, and people
get very annoyed at having their prompt and typing changed to weird
colors.
color(ATTR[, ATTR ...])
color() 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. It doesn't
print it out, just returns it, so you'll have to print it yourself
if you want to. This is so that you can save it as a string, pass
it to something else, send it to a file handle, or do anything else
with it that you might care to. color() throws an exception if
given an invalid attribute.
colored(STRING, ATTR[, ATTR ...])
colored(ATTR-REF, STRING[, STRING...])
As an aid in resetting colors, colored() takes a scalar as the
first argument and any number of attribute strings as the second
argument and 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, colored() just puts attribute codes at the beginning and
end of the string, but if you set $Term::ANSIColor::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 contains newlines and you're using
background colors, since a background color that persists across a
newline is often interpreted by the terminal as providing the
default background color for the next line. Programs like pagers
can also be confused by attributes that span lines. Normally
you'll want to set $Term::ANSIColor::EACHLINE to "\n" to use this
feature.
Particularly consider setting $Term::ANSIColor::EACHLINE if you are
interleaving output to standard output and standard error and you
aren't flushing standard output (via autoflush() or setting $|).
If you don't, the code to reset the color may unexpectedly sit in
the standard output buffer rather than going to the display,
causing standard error output to appear in the wrong color.
uncolor(ESCAPE)
uncolor() performs the opposite translation as color(), turning
escape sequences into a list of strings corresponding to the
attributes being set by those sequences. uncolor() will never
return "ansi16" through "ansi255", instead preferring the "grey"
and "rgb" names (and likewise for "on_ansi16" through
"on_ansi255").
colorstrip(STRING[, STRING ...])
colorstrip() removes all color escape sequences from the provided
strings, returning the modified strings separately in array context
or joined together in scalar context. Its arguments are not
modified.
colorvalid(ATTR[, ATTR ...])
colorvalid() takes attribute strings the same as color() and
returns true if all attributes are known and false otherwise.
coloralias(ALIAS[, ATTR ...])
If ATTR is specified, it is interpreted as a list of space-
separated strings naming attributes or existing aliases. In this
case, coloralias() sets up an alias of ALIAS for the set of
attributes given by ATTR. From that point forward, ALIAS can be
passed into color(), colored(), and colorvalid() and will have the
same meaning as the sequence of attributes given in ATTR. One
possible use of this facility is to give more meaningful names to
the 256-color RGB colors. Only ASCII alphanumerics, ".", "_", and
"-" are allowed in alias names.
If ATTR includes aliases, those aliases will be expanded at
definition time and their values will be used to define the new
alias. This means that if you define an alias A in terms of
another alias B, and then later redefine alias B, the value of
alias A will not change.
If ATTR is not specified, coloralias() returns the standard
attribute or attributes to which ALIAS is aliased, if any, or undef
if ALIAS does not exist. If it is aliased to multiple attributes,
the return value will be a single string and the attributes will be
separated by spaces.
This is the same facility used by the ANSI_COLORS_ALIASES
environment variable (see "ENVIRONMENT" below) but can be used at
runtime, not just when the module is loaded.
Later invocations of coloralias() with the same ALIAS will override
earlier aliases. There is no way to remove an alias.
Aliases have no effect on the return value of uncolor().
WARNING: Aliases are global and affect all callers in the same
process. There is no way to set an alias limited to a particular
block of code or a particular object.
Constant Interface
Alternately, if you import ":constants", you can use the following
constants directly:
CLEAR RESET BOLD DARK
FAINT ITALIC UNDERLINE UNDERSCORE
BLINK REVERSE CONCEALED
BLACK RED GREEN YELLOW
BLUE MAGENTA CYAN WHITE
BRIGHT_BLACK BRIGHT_RED BRIGHT_GREEN BRIGHT_YELLOW
BRIGHT_BLUE BRIGHT_MAGENTA BRIGHT_CYAN BRIGHT_WHITE
ON_BLACK ON_RED ON_GREEN ON_YELLOW
ON_BLUE ON_MAGENTA ON_CYAN ON_WHITE
ON_BRIGHT_BLACK ON_BRIGHT_RED ON_BRIGHT_GREEN ON_BRIGHT_YELLOW
ON_BRIGHT_BLUE ON_BRIGHT_MAGENTA ON_BRIGHT_CYAN ON_BRIGHT_WHITE
These are the same as color('attribute') and can be used if you prefer
typing:
print BOLD BLUE ON_WHITE "Text", RESET, "\n";
to
print colored ("Text", 'bold blue on_white'), "\n";
(Note that the newline is kept separate to avoid confusing the terminal
as described above since a background color is being used.)
If you import ":constants256", you can use the following constants
directly:
ANSI0 .. ANSI255
GREY0 .. GREY23
RGBXYZ (for X, Y, and Z values from 0 to 5, like RGB000 or RGB515)
ON_ANSI0 .. ON_ANSI255
ON_GREY0 .. ON_GREY23
ON_RGBXYZ (for X, Y, and Z values from 0 to 5)
Note that ":constants256" does not include the other constants, so if
you want to mix both, you need to include ":constants" as well. You
may want to explicitly import at least "RESET", as in:
use Term::ANSIColor 4.00 qw(RESET :constants256);
True color and aliases are not supported by the constant interface.
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::ANSIColor::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 afterward, whereas:
print BOLD, BLUE, "Text\n";
will not. If you are using background colors, you will probably want
to either use say() (in newer versions of Perl) or print the newline
with a separate print statement to avoid confusing the terminal.
If $Term::ANSIColor::AUTOLOCAL is set (see below), it takes precedence
over $Term::ANSIColor::AUTORESET, and the latter is ignored.
The subroutine interface has the advantage over the constants interface
in that only two subroutines are exported into your namespace, versus
thirty-eight in the constants interface, and aliases and true color
attributes are supported. On the flip side, the constants interface
has the advantage of better compile time error checking, since
misspelled names of colors or attributes in calls to color() and
colored() won't be caught until runtime whereas misspelled names of
constants will be caught at compile time. So, pollute your namespace
with almost two dozen subroutines that you may not even use that often,
or risk a silly bug by mistyping an attribute. Your choice, TMTOWTDI
after all.
The Color Stack
You can import ":pushpop" and maintain a stack of colors using
PUSHCOLOR, POPCOLOR, and LOCALCOLOR. PUSHCOLOR takes the attribute
string that starts its argument and pushes it onto a stack of
attributes. POPCOLOR removes the top of the stack and restores the
previous attributes set by the argument of a prior PUSHCOLOR.
LOCALCOLOR surrounds its argument in a PUSHCOLOR and POPCOLOR so that
the color resets afterward.
If $Term::ANSIColor::AUTOLOCAL is set, each sequence of color constants
will be implicitly preceded by LOCALCOLOR. In other words, the
following:
{
local $Term::ANSIColor::AUTOLOCAL = 1;
print BLUE "Text\n";
}
is equivalent to:
print LOCALCOLOR BLUE "Text\n";
If $Term::ANSIColor::AUTOLOCAL is set, it takes precedence over
$Term::ANSIColor::AUTORESET, and the latter is ignored.
When using PUSHCOLOR, POPCOLOR, and LOCALCOLOR, it's particularly
important to not put commas between the constants.
print PUSHCOLOR BLUE "Text\n";
will correctly push BLUE onto the top of the stack.
print PUSHCOLOR, BLUE, "Text\n"; # wrong!
will not, and a subsequent pop won't restore the correct attributes.
PUSHCOLOR pushes the attributes set by its argument, which is normally
a string of color constants. It can't ask the terminal what the
current attributes are.
Supporting CLICOLOR
<https://bixense.com/clicolors/> proposes a standard for enabling and
disabling color output from console commands using two environment
variables, CLICOLOR and CLICOLOR_FORCE. Term::ANSIColor cannot
automatically support this standard, since the correct action depends
on where the output is going and Term::ANSIColor may be used in a
context where colors should always be generated even if CLICOLOR is set
in the environment. But you can use the supported environment variable
ANSI_COLORS_DISABLED to implement CLICOLOR in your own programs with
code like this:
if (exists($ENV{CLICOLOR}) && $ENV{CLICOLOR} == 0) {
if (!$ENV{CLICOLOR_FORCE}) {
$ENV{ANSI_COLORS_DISABLED} = 1;
}
}
If you are using the constant interface, be sure to include this code
before you use any color constants (such as at the very top of your
script), since this environment variable is only honored the first time
a color constant is seen.
Be aware that this will export ANSI_COLORS_DISABLED to any child
processes of your program as well.
DIAGNOSTICS
Bad color mapping %s
(W) The specified color mapping from ANSI_COLORS_ALIASES is not
valid and could not be parsed. It was ignored.
Bad escape sequence %s
(F) You passed an invalid ANSI escape sequence to uncolor().
Bareword "%s" not allowed while "strict subs" in use
(F) You probably mistyped a constant color name such as:
$Foobar = FOOBAR . "This line should be blue\n";
or:
@Foobar = FOOBAR, "This line should be blue\n";
This will only show up under use strict (another good reason to run
under use strict).
Cannot alias standard color %s
(F) The alias name passed to coloralias() matches a standard color
name. Standard color names cannot be aliased.
Cannot alias standard color %s in %s
(W) The same, but in ANSI_COLORS_ALIASES. The color mapping was
ignored.
Invalid alias name %s
(F) You passed an invalid alias name to coloralias(). Alias names
must consist only of alphanumerics, ".", "-", and "_".
Invalid alias name %s in %s
(W) You specified an invalid alias name on the left hand of the
equal sign in a color mapping in ANSI_COLORS_ALIASES. The color
mapping was ignored.
Invalid attribute name %s
(F) You passed an invalid attribute name to color(), colored(), or
coloralias().
Invalid attribute name %s in %s
(W) You specified an invalid attribute name on the right hand of
the equal sign in a color mapping in ANSI_COLORS_ALIASES. The
color mapping was ignored.
Name "%s" used only once: possible typo
(W) 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
(F) 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.
No name for escape sequence %s
(F) The ANSI escape sequence passed to uncolor() contains escapes
which aren't recognized and can't be translated to names.
ENVIRONMENT
ANSI_COLORS_ALIASES
This environment variable allows the user to specify custom color
aliases that will be understood by color(), colored(), and
colorvalid(). None of the other functions will be affected, and no
new color constants will be created. The custom colors are aliases
for existing color names; no new escape sequences can be
introduced. Only alphanumerics, ".", "_", and "-" are allowed in
alias names.
The format is:
ANSI_COLORS_ALIASES='newcolor1=oldcolor1,newcolor2=oldcolor2'
Whitespace is ignored. The alias value can be a single attribute
or a space-separated list of attributes.
For example the Solarized <https://ethanschoonover.com/solarized>
colors can be mapped with:
ANSI_COLORS_ALIASES='\
base00=bright_yellow, on_base00=on_bright_yellow,\
base01=bright_green, on_base01=on_bright_green, \
base02=black, on_base02=on_black, \
base03=bright_black, on_base03=on_bright_black, \
base0=bright_blue, on_base0=on_bright_blue, \
base1=bright_cyan, on_base1=on_bright_cyan, \
base2=white, on_base2=on_white, \
base3=bright_white, on_base3=on_bright_white, \
orange=bright_red, on_orange=on_bright_red, \
violet=bright_magenta,on_violet=on_bright_magenta'
This environment variable is read and applied when the
Term::ANSIColor module is loaded and is then subsequently ignored.
Changes to ANSI_COLORS_ALIASES after the module is loaded will have
no effect. See coloralias() for an equivalent facility that can be
used at runtime.
ANSI_COLORS_DISABLED
If this environment variable is set to a true value, all of the
functions defined by this module (color(), colored(), and all of
the constants) will not output any escape sequences and instead
will just return the empty string or pass through the original text
as appropriate. This is intended to support easy use of scripts
using this module on platforms that don't support ANSI escape
sequences.
NO_COLOR
If this environment variable is set to any value, it suppresses
generation of escape sequences the same as if ANSI_COLORS_DISABLED
is set to a true value. This implements the
<https://no-color.org/> informal standard. Programs that want to
enable color despite NO_COLOR being set will need to unset that
environment variable before any constant or function provided by
this module is used.
COMPATIBILITY
Term::ANSIColor was first included with Perl in Perl 5.6.0.
The uncolor() function and support for ANSI_COLORS_DISABLED were added
in Term::ANSIColor 1.04, included in Perl 5.8.0.
Support for dark was added in Term::ANSIColor 1.08, included in Perl
5.8.4.
The color stack, including the ":pushpop" import tag, PUSHCOLOR,
POPCOLOR, LOCALCOLOR, and the $Term::ANSIColor::AUTOLOCAL variable, was
added in Term::ANSIColor 2.00, included in Perl 5.10.1.
colorstrip() was added in Term::ANSIColor 2.01 and colorvalid() was
added in Term::ANSIColor 2.02, both included in Perl 5.11.0.
Support for colors 8 through 15 (the "bright_" variants) was added in
Term::ANSIColor 3.00, included in Perl 5.13.3.
Support for italic was added in Term::ANSIColor 3.02, included in Perl
5.17.1.
Support for colors 16 through 256 (the "ansi", "rgb", and "grey"
colors), the ":constants256" import tag, the coloralias() function, and
support for the ANSI_COLORS_ALIASES environment variable were added in
Term::ANSIColor 4.00, included in Perl 5.17.8.
$Term::ANSIColor::AUTOLOCAL was changed to take precedence over
$Term::ANSIColor::AUTORESET, rather than the other way around, in
Term::ANSIColor 4.00, included in Perl 5.17.8.
"ansi16" through "ansi255", as aliases for the "rgb" and "grey" colors,
and the corresponding "on_ansi" names and "ANSI" and "ON_ANSI"
constants were added in Term::ANSIColor 4.06, included in Perl 5.25.7.
Support for true color (the "rNNNgNNNbNNN" and "on_rNNNgNNNbNNN"
attributes), defining aliases in terms of other aliases, and aliases
mapping to multiple attributes instead of only a single attribute was
added in Term::ANSIColor 5.00.
Support for NO_COLOR was added in Term::ANSIColor 5.01.
RESTRICTIONS
Both colored() and many uses of the color constants will add the reset
escape sequence after a newline. If a program mixes colored output to
standard output with output to standard error, this can result in the
standard error text having the wrong color because the reset escape
sequence hasn't yet been flushed to the display (since standard output
to a terminal is line-buffered by default). To avoid this, either set
autoflush() on STDOUT or set $Term::ANSIColor::EACHLINE to "\n".
It would be nice if one could leave off the commas around the constants
entirely and just say:
print BOLD BLUE ON_WHITE "Text\n" RESET;
but the syntax of Perl doesn't allow this. You need a comma after the
string. (Of course, you may consider it a bug that commas between all
the constants aren't required, in which case you may feel free to
insert commas unless you're using $Term::ANSIColor::AUTORESET or
PUSHCOLOR/POPCOLOR.)
For easier debugging, you may prefer to always use the commas when not
setting $Term::ANSIColor::AUTORESET or PUSHCOLOR/POPCOLOR so that
you'll get a fatal compile error rather than a warning.
It's not possible to use this module to embed formatting and color
attributes using Perl formats. They replace the escape character with
a space (as documented in perlform(1)), resulting in garbled output
from the unrecognized attribute. Even if there were a way around that
problem, the format doesn't know that the non-printing escape sequence
is zero-length and would incorrectly format the output. For formatted
output using color or other attributes, either use sprintf() instead or
use formline() and then add the color or other attributes after
formatting and before output.
NOTES
The codes generated by this module are standard terminal control codes,
complying with ECMA-048 and ISO 6429 (generally referred to as "ANSI
color" for the color codes). The non-color control codes (bold, dark,
italic, underline, and reverse) are part of the earlier ANSI X3.64
standard for control sequences for video terminals and peripherals.
Note that not all displays are ISO 6429-compliant, or even
X3.64-compliant (or are even attempting to be so). This module will
not work as expected on displays that do not honor these escape
sequences, such as cmd.exe, 4nt.exe, and command.com under either
Windows NT or Windows 2000. They may just be ignored, or they may
display as an ESC character followed by some apparent garbage.
Jean Delvare provided the following table of different common terminal
emulators and their support for the various attributes and others have
helped me flesh it out:
clear bold faint under blink reverse conceal
------------------------------------------------------------------------
xterm yes yes no yes yes yes yes
linux yes yes yes bold yes yes no
rxvt yes yes no yes bold/black yes no
dtterm yes yes yes yes reverse yes yes
teraterm yes reverse no yes rev/red yes no
aixterm kinda normal no yes no yes yes
PuTTY yes color no yes no yes no
Windows yes no no no no yes no
Cygwin SSH yes yes no color color color yes
Terminal.app yes yes no yes yes yes yes
Windows is Windows telnet, Cygwin SSH is the OpenSSH implementation
under Cygwin on Windows NT, and Mac Terminal is the Terminal
application in Mac OS X. Where the entry is other than yes or no, that
emulator displays the given attribute as something else instead. Note
that on an aixterm, clear doesn't reset colors; you have to explicitly
set the colors back to what you want. More entries in this table are
welcome.
Support for code 3 (italic) is rare and therefore not mentioned in that
table. It is not believed to be fully supported by any of the
terminals listed, although it's displayed as green in the Linux
console, but it is reportedly supported by urxvt.
Note that codes 6 (rapid blink) and 9 (strike-through) are specified in
ANSI X3.64 and ECMA-048 but are not commonly supported by most displays
and emulators and therefore aren't supported by this module. ECMA-048
also specifies a large number of other attributes, including a sequence
of attributes for font changes, Fraktur characters, double-underlining,
framing, circling, and overlining. As none of these attributes are
widely supported or useful, they also aren't currently supported by
this module.
Most modern X terminal emulators support 256 colors. Known to not
support those colors are aterm, rxvt, Terminal.app, and TTY/VC.
For information on true color support in various terminal emulators,
see True Colour support <https://gist.github.com/XVilka/8346728>.
AUTHORS
Original idea (using constants) by Zenin, reimplemented using subs by
Russ Allbery <rra@cpan.org>, and then combined with the original idea
by Russ with input from Zenin. 256-color support is based on work by
Kurt Starsinic. Russ Allbery now maintains this module.
PUSHCOLOR, POPCOLOR, and LOCALCOLOR were contributed by openmethods.com
voice solutions.
COPYRIGHT AND LICENSE
Copyright 1996-1998, 2000-2002, 2005-2006, 2008-2018, 2020 Russ Allbery
<rra@cpan.org>
Copyright 1996 Zenin
Copyright 2012 Kurt Starsinic <kstarsinic@gmail.com>
This program is free software; you may redistribute it and/or modify it
under the same terms as Perl itself.
SEE ALSO
The CPAN module Term::ExtendedColor provides a different and more
comprehensive interface for 256-color emulators that may be more
convenient. The CPAN module Win32::Console::ANSI provides ANSI color
(and other escape sequence) support in the Win32 Console environment.
The CPAN module Term::Chrome provides a different interface using
objects and operator overloading.
ECMA-048 is available on-line (at least at the time of this writing) at
<https://www.ecma-international.org/publications/standards/Ecma-048.htm>.
ISO 6429 is available from ISO for a charge; the author of this module
does not own a copy of it. Since the source material for ISO 6429 was
ECMA-048 and the latter is available for free, there seems little
reason to obtain the ISO standard.
The 256-color control sequences are documented at
<https://invisible-island.net/xterm/ctlseqs/ctlseqs.html> (search for
256-color).
Information about true color support in various terminal emulators and
test programs you can run to check the true color support in your
terminal emulator are available at
<https://gist.github.com/XVilka/8346728>.
CLICOLORS <https://bixense.com/clicolors/> and NO_COLOR <https://no-
color.org/> are useful standards to be aware of, and ideally follow,
for any application using color. Term::ANSIColor complies with the
latter.
The current version of this module is always available from its web
site at <https://www.eyrie.org/~eagle/software/ansicolor/>. It is also
part of the Perl core distribution as of 5.6.0.
perl v5.34.0 2020-06-14 Term::ANSIColor(3pm)
perl 5.34.0 - Generated Fri Mar 4 12:53:42 CST 2022