1 # Term::ANSIColor -- Color screen output using ANSI escape sequences.
2 # $Id: ANSIColor.pm,v 1.10 2005/08/21 18:31:58 eagle Exp $
4 # Copyright 1996, 1997, 1998, 2000, 2001, 2002, 2005
5 # by Russ Allbery <rra@stanford.edu> and Zenin
7 # This program is free software; you may redistribute it and/or modify it
8 # under the same terms as Perl itself.
10 # Ah, September, when the sysadmins turn colors and fall off the trees....
13 ##############################################################################
14 # Modules and declarations
15 ##############################################################################
17 package Term::ANSIColor;
21 use vars qw($AUTOLOAD $AUTORESET $EACHLINE @ISA @EXPORT @EXPORT_OK
22 %EXPORT_TAGS $VERSION %attributes %attributes_r);
26 @EXPORT = qw(color colored);
27 @EXPORT_OK = qw(uncolor);
28 %EXPORT_TAGS = (constants => [qw(CLEAR RESET BOLD DARK UNDERLINE UNDERSCORE
29 BLINK REVERSE CONCEALED BLACK RED GREEN
30 YELLOW BLUE MAGENTA CYAN WHITE ON_BLACK
31 ON_RED ON_GREEN ON_YELLOW ON_BLUE ON_MAGENTA
33 Exporter::export_ok_tags ('constants');
35 # Don't use the CVS revision as the version, since this module is also in Perl
36 # core and too many things could munge CVS magic revision strings.
39 ##############################################################################
40 # Internal data structures
41 ##############################################################################
43 %attributes = ('clear' => 0,
53 'black' => 30, 'on_black' => 40,
54 'red' => 31, 'on_red' => 41,
55 'green' => 32, 'on_green' => 42,
56 'yellow' => 33, 'on_yellow' => 43,
57 'blue' => 34, 'on_blue' => 44,
58 'magenta' => 35, 'on_magenta' => 45,
59 'cyan' => 36, 'on_cyan' => 46,
60 'white' => 37, 'on_white' => 47);
62 # Reverse lookup. Alphabetically first name for a sequence is preferred.
63 for (reverse sort keys %attributes) {
64 $attributes_r{$attributes{$_}} = $_;
67 ##############################################################################
68 # Implementation (constant form)
69 ##############################################################################
71 # Time to have fun! We now want to define the constant subs, which are named
72 # the same as the attributes above but in all caps. Each constant sub needs
73 # to act differently depending on whether $AUTORESET is set. Without
76 # BLUE "text\n" ==> "\e[34mtext\n"
78 # If $AUTORESET is set, we should instead get:
80 # BLUE "text\n" ==> "\e[34mtext\n\e[0m"
82 # The sub also needs to handle the case where it has no arguments correctly.
83 # Maintaining all of this as separate subs would be a major nightmare, as well
84 # as duplicate the %attributes hash, so instead we define an AUTOLOAD sub to
85 # define the constant subs on demand. To do that, we check the name of the
86 # called sub against the list of attributes, and if it's an all-caps version
87 # of one of them, we define the sub on the fly and then run it.
89 # If the environment variable ANSI_COLORS_DISABLED is set, turn all of the
90 # generated subs into pass-through functions that don't add any escape
91 # sequences. This is to make it easier to write scripts that also work on
92 # systems without any ANSI support, like Windows consoles.
94 my $enable_colors = !defined $ENV{ANSI_COLORS_DISABLED};
96 ($sub = $AUTOLOAD) =~ s/^.*:://;
97 my $attr = $attributes{lc $sub};
98 if ($sub =~ /^[A-Z_]+$/ && defined $attr) {
99 $attr = $enable_colors ? "\e[" . $attr . 'm' : '';
102 if (\$AUTORESET && \@_) {
103 '$attr' . "\@_" . "\e[0m";
112 Carp::croak ("undefined subroutine &$AUTOLOAD called");
116 ##############################################################################
117 # Implementation (attribute string form)
118 ##############################################################################
120 # Return the escape code for a given set of color attributes.
122 return '' if defined $ENV{ANSI_COLORS_DISABLED};
123 my @codes = map { split } @_;
127 unless (defined $attributes{$_}) {
129 Carp::croak ("Invalid attribute name $_");
131 $attribute .= $attributes{$_} . ';';
134 ($attribute ne '') ? "\e[${attribute}m" : undef;
137 # Return a list of named color attributes for a given set of escape codes.
138 # Escape sequences can be given with or without enclosing "\e[" and "m". The
139 # empty escape sequence '' or "\e[m" gives an empty list of attrs.
144 $escape =~ s/^\e\[//;
146 unless ($escape =~ /^((?:\d+;)*\d*)$/) {
148 Carp::croak ("Bad escape sequence $_");
150 push (@nums, split (/;/, $1));
153 $_ += 0; # Strip leading zeroes
154 my $name = $attributes_r{$_};
155 if (!defined $name) {
157 Carp::croak ("No name for escape sequence $_" );
159 push (@result, $name);
164 # Given a string and a set of attributes, returns the string surrounded by
165 # escape codes to set those attributes and then clear them at the end of the
166 # string. The attributes can be given either as an array ref as the first
167 # argument or as a list as the second and subsequent arguments. If $EACHLINE
168 # is set, insert a reset before each occurrence of the string $EACHLINE and
169 # the starting attribute code after the string $EACHLINE, so that no attribute
170 # crosses line delimiters (this is often desirable if the output is to be
171 # piped to a pager or some other program).
173 my ($string, @codes);
176 $string = join ('', @_);
181 return $string if defined $ENV{ANSI_COLORS_DISABLED};
182 if (defined $EACHLINE) {
183 my $attr = color (@codes);
185 map { $_ ne $EACHLINE ? $attr . $_ . "\e[0m" : $_ }
186 grep { length ($_) > 0 }
187 split (/(\Q$EACHLINE\E)/, $string);
189 color (@codes) . $string . "\e[0m";
193 ##############################################################################
194 # Module return value and documentation
195 ##############################################################################
197 # Ensure we evaluate to true.
203 Term::ANSIColor - Color screen output using ANSI escape sequences
208 print color 'bold blue';
209 print "This text is bold blue.\n";
211 print "This text is normal.\n";
212 print colored ("Yellow on magenta.\n", 'yellow on_magenta');
213 print "This text is normal.\n";
214 print colored ['yellow on_magenta'], "Yellow on magenta.\n";
216 use Term::ANSIColor qw(uncolor);
217 print uncolor '01;31', "\n";
219 use Term::ANSIColor qw(:constants);
220 print BOLD, BLUE, "This text is in bold blue.\n", RESET;
222 use Term::ANSIColor qw(:constants);
223 $Term::ANSIColor::AUTORESET = 1;
224 print BOLD BLUE "This text is in bold blue.\n";
225 print "This text is normal.\n";
229 This module has two interfaces, one through color() and colored() and the
230 other through constants. It also offers the utility function uncolor(),
231 which has to be explicitly imported to be used (see L<SYNOPSIS>).
233 color() takes any number of strings as arguments and considers them to be
234 space-separated lists of attributes. It then forms and returns the escape
235 sequence to set those attributes. It doesn't print it out, just returns it,
236 so you'll have to print it yourself if you want to (this is so that you can
237 save it as a string, pass it to something else, send it to a file handle, or
238 do anything else with it that you might care to).
240 uncolor() performs the opposite translation, turning escape sequences
241 into a list of strings.
243 The recognized attributes (all of which should be fairly intuitive) are
244 clear, reset, dark, bold, underline, underscore, blink, reverse, concealed,
245 black, red, green, yellow, blue, magenta, on_black, on_red, on_green,
246 on_yellow, on_blue, on_magenta, on_cyan, and on_white. Case is not
247 significant. Underline and underscore are equivalent, as are clear and
248 reset, so use whichever is the most intuitive to you. The color alone sets
249 the foreground color, and on_color sets the background color.
251 Note that not all attributes are supported by all terminal types, and some
252 terminals may not support any of these sequences. Dark, blink, and
253 concealed in particular are frequently not implemented.
255 Attributes, once set, last until they are unset (by sending the attribute
256 "reset"). Be careful to do this, or otherwise your attribute will last
257 after your script is done running, and people get very annoyed at having
258 their prompt and typing changed to weird colors.
260 As an aid to help with this, colored() takes a scalar as the first argument
261 and any number of attribute strings as the second argument and returns the
262 scalar wrapped in escape codes so that the attributes will be set as
263 requested before the string and reset to normal after the string.
264 Alternately, you can pass a reference to an array as the first argument, and
265 then the contents of that array will be taken as attributes and color codes
266 and the remainder of the arguments as text to colorize.
268 Normally, colored() just puts attribute codes at the beginning and end of
269 the string, but if you set $Term::ANSIColor::EACHLINE to some string, that
270 string will be considered the line delimiter and the attribute will be set
271 at the beginning of each line of the passed string and reset at the end of
272 each line. This is often desirable if the output is being sent to a program
273 like a pager that can be confused by attributes that span lines. Normally
274 you'll want to set $Term::ANSIColor::EACHLINE to C<"\n"> to use this
277 Alternately, if you import C<:constants>, you can use the constants CLEAR,
278 RESET, BOLD, DARK, UNDERLINE, UNDERSCORE, BLINK, REVERSE, CONCEALED, BLACK,
279 RED, GREEN, YELLOW, BLUE, MAGENTA, CYAN, WHITE, ON_BLACK, ON_RED, ON_GREEN,
280 ON_YELLOW, ON_BLUE, ON_MAGENTA, ON_CYAN, and ON_WHITE directly. These are
281 the same as color('attribute') and can be used if you prefer typing:
283 print BOLD BLUE ON_WHITE "Text\n", RESET;
287 print colored ("Text\n", 'bold blue on_white');
289 When using the constants, if you don't want to have to remember to add the
290 C<, RESET> at the end of each print line, you can set
291 $Term::ANSIColor::AUTORESET to a true value. Then, the display mode will
292 automatically be reset if there is no comma after the constant. In other
293 words, with that variable set:
295 print BOLD BLUE "Text\n";
297 will reset the display mode afterwards, whereas:
299 print BOLD, BLUE, "Text\n";
303 The subroutine interface has the advantage over the constants interface in
304 that only two subroutines are exported into your namespace, versus
305 twenty-two in the constants interface. On the flip side, the constants
306 interface has the advantage of better compile time error checking, since
307 misspelled names of colors or attributes in calls to color() and colored()
308 won't be caught until runtime whereas misspelled names of constants will be
309 caught at compile time. So, pollute your namespace with almost two dozen
310 subroutines that you may not even use that often, or risk a silly bug by
311 mistyping an attribute. Your choice, TMTOWTDI after all.
317 =item Bad escape sequence %s
319 (F) You passed an invalid ANSI escape sequence to uncolor().
321 =item Bareword "%s" not allowed while "strict subs" in use
323 (F) You probably mistyped a constant color name such as:
325 $Foobar = FOOBAR . "This line should be blue\n";
329 @Foobar = FOOBAR, "This line should be blue\n";
331 This will only show up under use strict (another good reason to run under
334 =item Invalid attribute name %s
336 (F) You passed an invalid attribute name to either color() or colored().
338 =item Name "%s" used only once: possible typo
340 (W) You probably mistyped a constant color name such as:
342 print FOOBAR "This text is color FOOBAR\n";
344 It's probably better to always use commas after constant names in order to
345 force the next error.
347 =item No comma allowed after filehandle
349 (F) You probably mistyped a constant color name such as:
351 print FOOBAR, "This text is color FOOBAR\n";
353 Generating this fatal compile error is one of the main advantages of using
354 the constants interface, since you'll immediately know if you mistype a
357 =item No name for escape sequence %s
359 (F) The ANSI escape sequence passed to uncolor() contains escapes which
360 aren't recognized and can't be translated to names.
368 =item ANSI_COLORS_DISABLED
370 If this environment variable is set, all of the functions defined by this
371 module (color(), colored(), and all of the constants not previously used in
372 the program) will not output any escape sequences and instead will just
373 return the empty string or pass through the original text as appropriate.
374 This is intended to support easy use of scripts using this module on
375 platforms that don't support ANSI escape sequences.
377 For it to have its proper effect, this environment variable must be set
378 before any color constants are used in the program.
384 It would be nice if one could leave off the commas around the constants
385 entirely and just say:
387 print BOLD BLUE ON_WHITE "Text\n" RESET;
389 but the syntax of Perl doesn't allow this. You need a comma after the
390 string. (Of course, you may consider it a bug that commas between all the
391 constants aren't required, in which case you may feel free to insert commas
392 unless you're using $Term::ANSIColor::AUTORESET.)
394 For easier debugging, you may prefer to always use the commas when not
395 setting $Term::ANSIColor::AUTORESET so that you'll get a fatal compile error
396 rather than a warning.
400 The codes generated by this module are standard terminal control codes,
401 complying with ECMA-48 and ISO 6429 (generally referred to as "ANSI color"
402 for the color codes). The non-color control codes (bold, dark, italic,
403 underline, and reverse) are part of the earlier ANSI X3.64 standard for
404 control sequences for video terminals and peripherals.
406 Note that not all displays are ISO 6429-compliant, or even X3.64-compliant
407 (or are even attempting to be so). This module will not work as expected on
408 displays that do not honor these escape sequences, such as cmd.exe, 4nt.exe,
409 and command.com under either Windows NT or Windows 2000. They may just be
410 ignored, or they may display as an ESC character followed by some apparent
413 Jean Delvare provided the following table of different common terminal
414 emulators and their support for the various attributes and others have helped
417 clear bold dark under blink reverse conceal
418 ------------------------------------------------------------------------
419 xterm yes yes no yes bold yes yes
420 linux yes yes yes bold yes yes no
421 rxvt yes yes no yes bold/black yes no
422 dtterm yes yes yes yes reverse yes yes
423 teraterm yes reverse no yes rev/red yes no
424 aixterm kinda normal no yes no yes yes
425 PuTTY yes color no yes no yes no
426 Windows yes no no no no yes no
427 Cygwin SSH yes yes no color color color yes
428 Mac Terminal yes yes no yes yes yes yes
430 Windows is Windows telnet, Cygwin SSH is the OpenSSH implementation under
431 Cygwin on Windows NT, and Mac Terminal is the Terminal application in Mac OS
432 X. Where the entry is other than yes or no, that emulator displays the
433 given attribute as something else instead. Note that on an aixterm, clear
434 doesn't reset colors; you have to explicitly set the colors back to what you
435 want. More entries in this table are welcome.
437 Note that codes 3 (italic), 6 (rapid blink), and 9 (strikethrough) are
438 specified in ANSI X3.64 and ECMA-048 but are not commonly supported by most
439 displays and emulators and therefore aren't supported by this module at the
440 present time. ECMA-048 also specifies a large number of other attributes,
441 including a sequence of attributes for font changes, Fraktur characters,
442 double-underlining, framing, circling, and overlining. As none of these
443 attributes are widely supported or useful, they also aren't currently
444 supported by this module.
448 ECMA-048 is available on-line (at least at the time of this writing) at
449 L<http://www.ecma-international.org/publications/standards/ECMA-048.HTM>.
451 ISO 6429 is available from ISO for a charge; the author of this module does
452 not own a copy of it. Since the source material for ISO 6429 was ECMA-048
453 and the latter is available for free, there seems little reason to obtain
456 The current version of this module is always available from its web site at
457 L<http://www.eyrie.org/~eagle/software/ansicolor/>. It is also part of the
458 Perl core distribution as of 5.6.0.
462 Original idea (using constants) by Zenin, reimplemented using subs by Russ
463 Allbery <rra@stanford.edu>, and then combined with the original idea by Russ
464 with input from Zenin. Russ Allbery now maintains this module.
466 =head1 COPYRIGHT AND LICENSE
468 Copyright 1996, 1997, 1998, 2000, 2001, 2002 Russ Allbery <rra@stanford.edu>
469 and Zenin. This program is free software; you may redistribute it and/or
470 modify it under the same terms as Perl itself.