1Term::ANSIColor(3) User Contributed Perl Documentation Term::ANSIColor(3)
2
6 Term::ANSIColor - Color screen output using ANSI escape sequences
7
9 use Term::ANSIColor;
10 print color('bold blue');
11 print "This text is bold blue.\n";
12 print color('reset');
13 print "This text is normal.\n";
14 print colored("Yellow on magenta.", 'yellow on_magenta'), "\n";
15 print "This text is normal.\n";
16 print colored(['yellow on_magenta'], 'Yellow on magenta.', "\n");
17 print colored(['red on_bright_yellow'], 'Red on bright yellow.', "\n");
18 print colored(['bright_red on_black'], 'Bright red on black.', "\n");
19 print "\n";
20 # Map escape sequences back to color names.
22 use Term::ANSIColor 1.04 qw(uncolor);
23 my @names = uncolor('01;31');
24 print join(q{ }, @names), "\n";
25 # Strip all color escape sequences.
27 use Term::ANSIColor 2.01 qw(colorstrip);
28 print colorstrip("\e[1mThis is bold\e[0m"), "\n";
29 # Determine whether a color is valid.
31 use Term::ANSIColor 2.02 qw(colorvalid);
32 my $valid = colorvalid('blue bold', 'on_magenta');
33 print "Color string is ", $valid ? "valid\n" : "invalid\n";
34 # Create new aliases for colors.
36 use Term::ANSIColor 4.00 qw(coloralias);
37 coloralias('alert', 'red');
38 print "Alert is ", coloralias('alert'), "\n";
39 print colored("This is in red.", 'alert'), "\n";
40 use Term::ANSIColor qw(:constants);
42 print BOLD, BLUE, "This text is in bold blue.\n", RESET;
43 use Term::ANSIColor qw(:constants);
45 {
46 local $Term::ANSIColor::AUTORESET = 1;
47 print BOLD BLUE "This text is in bold blue.\n";
48 print "This text is normal.\n";
49 }
50 use Term::ANSIColor 2.00 qw(:pushpop);
52 print PUSHCOLOR RED ON_GREEN "This text is red on green.\n";
53 print PUSHCOLOR BRIGHT_BLUE "This text is bright blue on green.\n";
54 print RESET BRIGHT_BLUE "This text is just bright blue.\n";
55 print POPCOLOR "Back to red on green.\n";
56 print LOCALCOLOR GREEN ON_BLUE "This text is green on blue.\n";
57 print "This text is red on green.\n";
58 {
59 local $Term::ANSIColor::AUTOLOCAL = 1;
60 print ON_BLUE "This text is red on blue.\n";
61 print "This text is red on green.\n";
62 }
63 print POPCOLOR "Back to whatever we started as.\n";
64
66 This module has two interfaces, one through color() and colored() and
67 the other through constants. It also offers the utility functions
68 uncolor(), colorstrip(), colorvalid(), and coloralias(), which have to
69 be explicitly imported to be used (see "SYNOPSIS").
70 If you are using Term::ANSIColor in a console command, consider
72 supporting the CLICOLOR standard. See "Supporting CLICOLOR" for more
73 information.
74 See "COMPATIBILITY" for the versions of Term::ANSIColor that introduced
76 particular features and the versions of Perl that included them.
77 Supported Colors
79 Terminal emulators that support color divide into four types: ones that
80 support only eight colors, ones that support sixteen, ones that support
81 256, and ones that support 24-bit color. This module provides the ANSI
82 escape codes for all of them. These colors are referred to as ANSI
83 colors 0 through 7 (normal), 8 through 15 (16-color), 16 through 255
84 (256-color), and true color (called direct-color by xterm).
85 Unfortunately, interpretation of colors 0 through 7 often depends on
87 whether the emulator supports eight colors or sixteen colors.
88 Emulators that only support eight colors (such as the Linux console)
89 will display colors 0 through 7 with normal brightness and ignore
90 colors 8 through 15, treating them the same as white. Emulators that
91 support 16 colors, such as gnome-terminal, normally display colors 0
92 through 7 as dim or darker versions and colors 8 through 15 as normal
93 brightness. On such emulators, the "normal" white (color 7) usually is
94 shown as pale grey, requiring bright white (15) to be used to get a
95 real white color. Bright black usually is a dark grey color, although
96 some terminals display it as pure black. Some sixteen-color terminal
97 emulators also treat normal yellow (color 3) as orange or brown, and
98 bright yellow (color 11) as yellow.
99 Following the normal convention of sixteen-color emulators, this module
101 provides a pair of attributes for each color. For every normal color
102 (0 through 7), the corresponding bright color (8 through 15) is
103 obtained by prepending the string "bright_" to the normal color name.
104 For example, "red" is color 1 and "bright_red" is color 9. The same
105 applies for background colors: "on_red" is the normal color and
106 "on_bright_red" is the bright color. Capitalize these strings for the
107 constant interface.
108 There is unfortunately no way to know whether the current emulator
110 supports more than eight colors, which makes the choice of colors
111 difficult. The most conservative choice is to use only the regular
112 colors, which are at least displayed on all emulators. However, they
113 will appear dark in sixteen-color terminal emulators, including most
114 common emulators in UNIX X environments. If you know the display is
115 one of those emulators, you may wish to use the bright variants
116 instead. Even better, offer the user a way to configure the colors for
117 a given application to fit their terminal emulator.
118 For 256-color emulators, this module additionally provides "ansi0"
120 through "ansi15", which are the same as colors 0 through 15 in sixteen-
121 color emulators but use the 256-color escape syntax, "grey0" through
122 "grey23" ranging from nearly black to nearly white, and a set of RGB
123 colors. The RGB colors are of the form "rgbRGB" where R, G, and B are
124 numbers from 0 to 5 giving the intensity of red, green, and blue. The
125 grey and RGB colors are also available as "ansi16" through "ansi255" if
126 you want simple names for all 256 colors. "on_" variants of all of
127 these colors are also provided. These colors may be ignored completely
128 on non-256-color terminals or may be misinterpreted and produce random
129 behavior. Additional attributes such as blink, italic, or bold may not
130 work with the 256-color palette.
131 For true color emulators, this module supports attributes of the form
133 "rNNNgNNNbNNN" and "on_rNNNgNNNbNNN" for all values of NNN between 0
134 and 255. These represent foreground and background colors,
135 respectively, with the RGB values given by the NNN numbers. These
136 colors may be ignored completely on non-true-color terminals or may be
137 misinterpreted and produce random behavior.
138 Function Interface
140 The function interface uses attribute strings to describe the colors
141 and text attributes to assign to text. The recognized non-color
142 attributes are clear, reset, bold, dark, faint, italic, underline,
143 underscore, blink, reverse, and concealed. Clear and reset (reset to
144 default attributes), dark and faint (dim and saturated), and underline
145 and underscore are equivalent, so use whichever is the most intuitive
146 to you.
147 Note that not all attributes are supported by all terminal types, and
149 some terminals may not support any of these sequences. Dark and faint,
150 italic, blink, and concealed in particular are frequently not
151 implemented.
152 The recognized normal foreground color attributes (colors 0 to 7) are:
154 black red green yellow blue magenta cyan white
156 The corresponding bright foreground color attributes (colors 8 to 15)
158 are:
159 bright_black bright_red bright_green bright_yellow
161 bright_blue bright_magenta bright_cyan bright_white
162 The recognized normal background color attributes (colors 0 to 7) are:
164 on_black on_red on_green on yellow
166 on_blue on_magenta on_cyan on_white
167 The recognized bright background color attributes (colors 8 to 15) are:
169 on_bright_black on_bright_red on_bright_green on_bright_yellow
171 on_bright_blue on_bright_magenta on_bright_cyan on_bright_white
172 For 256-color terminals, the recognized foreground colors are:
174 ansi0 .. ansi255
176 grey0 .. grey23
177 plus "rgbRGB" for R, G, and B values from 0 to 5, such as "rgb000" or
179 "rgb515". Similarly, the recognized background colors are:
180 on_ansi0 .. on_ansi255
182 on_grey0 .. on_grey23
183 plus "on_rgbRGB" for R, G, and B values from 0 to 5.
185 For true color terminals, the recognized foreground colors are
187 "rRRRgGGGbBBB" for RRR, GGG, and BBB values between 0 and 255.
188 Similarly, the recognized background colors are "on_rRRRgGGGbBBB" for
189 RRR, GGG, and BBB values between 0 and 255.
190 For any of the above listed attributes, case is not significant.
192 Attributes, once set, last until they are unset (by printing the
194 attribute "clear" or "reset"). Be careful to do this, or otherwise
195 your attribute will last after your script is done running, and people
196 get very annoyed at having their prompt and typing changed to weird
197 colors.
198 color(ATTR[, ATTR ...])
200 color() takes any number of strings as arguments and considers them
201 to be space-separated lists of attributes. It then forms and
202 returns the escape sequence to set those attributes. It doesn't
203 print it out, just returns it, so you'll have to print it yourself
204 if you want to. This is so that you can save it as a string, pass
205 it to something else, send it to a file handle, or do anything else
206 with it that you might care to. color() throws an exception if
207 given an invalid attribute.
208 colored(STRING, ATTR[, ATTR ...])
210 colored(ATTR-REF, STRING[, STRING...])
211 As an aid in resetting colors, colored() takes a scalar as the
212 first argument and any number of attribute strings as the second
213 argument and returns the scalar wrapped in escape codes so that the
214 attributes will be set as requested before the string and reset to
215 normal after the string. Alternately, you can pass a reference to
216 an array as the first argument, and then the contents of that array
217 will be taken as attributes and color codes and the remainder of
218 the arguments as text to colorize.
219 Normally, colored() just puts attribute codes at the beginning and
221 end of the string, but if you set $Term::ANSIColor::EACHLINE to
222 some string, that string will be considered the line delimiter and
223 the attribute will be set at the beginning of each line of the
224 passed string and reset at the end of each line. This is often
225 desirable if the output contains newlines and you're using
226 background colors, since a background color that persists across a
227 newline is often interpreted by the terminal as providing the
228 default background color for the next line. Programs like pagers
229 can also be confused by attributes that span lines. Normally
230 you'll want to set $Term::ANSIColor::EACHLINE to "\n" to use this
231 feature.
232 Particularly consider setting $Term::ANSIColor::EACHLINE if you are
234 interleaving output to standard output and standard error and you
235 aren't flushing standard output (via autoflush() or setting $|).
236 If you don't, the code to reset the color may unexpectedly sit in
237 the standard output buffer rather than going to the display,
238 causing standard error output to appear in the wrong color.
239 uncolor(ESCAPE)
241 uncolor() performs the opposite translation as color(), turning
242 escape sequences into a list of strings corresponding to the
243 attributes being set by those sequences. uncolor() will never
244 return "ansi16" through "ansi255", instead preferring the "grey"
245 and "rgb" names (and likewise for "on_ansi16" through
246 "on_ansi255").
247 colorstrip(STRING[, STRING ...])
249 colorstrip() removes all color escape sequences from the provided
250 strings, returning the modified strings separately in array context
251 or joined together in scalar context. Its arguments are not
252 modified.
253 colorvalid(ATTR[, ATTR ...])
255 colorvalid() takes attribute strings the same as color() and
256 returns true if all attributes are known and false otherwise.
257 coloralias(ALIAS[, ATTR ...])
259 If ATTR is specified, it is interpreted as a list of space-
260 separated strings naming attributes or existing aliases. In this
261 case, coloralias() sets up an alias of ALIAS for the set of
262 attributes given by ATTR. From that point forward, ALIAS can be
263 passed into color(), colored(), and colorvalid() and will have the
264 same meaning as the sequence of attributes given in ATTR. One
265 possible use of this facility is to give more meaningful names to
266 the 256-color RGB colors. Only ASCII alphanumerics, ".", "_", and
267 "-" are allowed in alias names.
268 If ATTR includes aliases, those aliases will be expanded at
270 definition time and their values will be used to define the new
271 alias. This means that if you define an alias A in terms of
272 another alias B, and then later redefine alias B, the value of
273 alias A will not change.
274 If ATTR is not specified, coloralias() returns the standard
276 attribute or attributes to which ALIAS is aliased, if any, or undef
277 if ALIAS does not exist. If it is aliased to multiple attributes,
278 the return value will be a single string and the attributes will be
279 separated by spaces.
280 This is the same facility used by the ANSI_COLORS_ALIASES
282 environment variable (see "ENVIRONMENT" below) but can be used at
283 runtime, not just when the module is loaded.
284 Later invocations of coloralias() with the same ALIAS will override
286 earlier aliases. There is no way to remove an alias.
287 Aliases have no effect on the return value of uncolor().
289 WARNING: Aliases are global and affect all callers in the same
291 process. There is no way to set an alias limited to a particular
292 block of code or a particular object.
293 Constant Interface
295 Alternately, if you import ":constants", you can use the following
296 constants directly:
297 CLEAR RESET BOLD DARK
299 FAINT ITALIC UNDERLINE UNDERSCORE
300 BLINK REVERSE CONCEALED
301 BLACK RED GREEN YELLOW
303 BLUE MAGENTA CYAN WHITE
304 BRIGHT_BLACK BRIGHT_RED BRIGHT_GREEN BRIGHT_YELLOW
305 BRIGHT_BLUE BRIGHT_MAGENTA BRIGHT_CYAN BRIGHT_WHITE
306 ON_BLACK ON_RED ON_GREEN ON_YELLOW
308 ON_BLUE ON_MAGENTA ON_CYAN ON_WHITE
309 ON_BRIGHT_BLACK ON_BRIGHT_RED ON_BRIGHT_GREEN ON_BRIGHT_YELLOW
310 ON_BRIGHT_BLUE ON_BRIGHT_MAGENTA ON_BRIGHT_CYAN ON_BRIGHT_WHITE
311 These are the same as color('attribute') and can be used if you prefer
313 typing:
314 print BOLD BLUE ON_WHITE "Text", RESET, "\n";
316 to
318 print colored ("Text", 'bold blue on_white'), "\n";
320 (Note that the newline is kept separate to avoid confusing the terminal
322 as described above since a background color is being used.)
323 If you import ":constants256", you can use the following constants
325 directly:
326 ANSI0 .. ANSI255
328 GREY0 .. GREY23
329 RGBXYZ (for X, Y, and Z values from 0 to 5, like RGB000 or RGB515)
331 ON_ANSI0 .. ON_ANSI255
333 ON_GREY0 .. ON_GREY23
334 ON_RGBXYZ (for X, Y, and Z values from 0 to 5)
336 Note that ":constants256" does not include the other constants, so if
338 you want to mix both, you need to include ":constants" as well. You
339 may want to explicitly import at least "RESET", as in:
340 use Term::ANSIColor 4.00 qw(RESET :constants256);
342 True color and aliases are not supported by the constant interface.
344 When using the constants, if you don't want to have to remember to add
346 the ", RESET" at the end of each print line, you can set
347 $Term::ANSIColor::AUTORESET to a true value. Then, the display mode
348 will automatically be reset if there is no comma after the constant.
349 In other words, with that variable set:
350 print BOLD BLUE "Text\n";
352 will reset the display mode afterward, whereas:
354 print BOLD, BLUE, "Text\n";
356 will not. If you are using background colors, you will probably want
358 to either use say() (in newer versions of Perl) or print the newline
359 with a separate print statement to avoid confusing the terminal.
360 If $Term::ANSIColor::AUTOLOCAL is set (see below), it takes precedence
362 over $Term::ANSIColor::AUTORESET, and the latter is ignored.
363 The subroutine interface has the advantage over the constants interface
365 in that only two subroutines are exported into your namespace, versus
366 thirty-eight in the constants interface, and aliases and true color
367 attributes are supported. On the flip side, the constants interface
368 has the advantage of better compile time error checking, since
369 misspelled names of colors or attributes in calls to color() and
370 colored() won't be caught until runtime whereas misspelled names of
371 constants will be caught at compile time. So, pollute your namespace
372 with almost two dozen subroutines that you may not even use that often,
373 or risk a silly bug by mistyping an attribute. Your choice, TMTOWTDI
374 after all.
375 The Color Stack
377 You can import ":pushpop" and maintain a stack of colors using
378 PUSHCOLOR, POPCOLOR, and LOCALCOLOR. PUSHCOLOR takes the attribute
379 string that starts its argument and pushes it onto a stack of
380 attributes. POPCOLOR removes the top of the stack and restores the
381 previous attributes set by the argument of a prior PUSHCOLOR.
382 LOCALCOLOR surrounds its argument in a PUSHCOLOR and POPCOLOR so that
383 the color resets afterward.
384 If $Term::ANSIColor::AUTOLOCAL is set, each sequence of color constants
386 will be implicitly preceded by LOCALCOLOR. In other words, the
387 following:
388 {
390 local $Term::ANSIColor::AUTOLOCAL = 1;
391 print BLUE "Text\n";
392 }
393 is equivalent to:
395 print LOCALCOLOR BLUE "Text\n";
397 If $Term::ANSIColor::AUTOLOCAL is set, it takes precedence over
399 $Term::ANSIColor::AUTORESET, and the latter is ignored.
400 When using PUSHCOLOR, POPCOLOR, and LOCALCOLOR, it's particularly
402 important to not put commas between the constants.
403 print PUSHCOLOR BLUE "Text\n";
405 will correctly push BLUE onto the top of the stack.
407 print PUSHCOLOR, BLUE, "Text\n"; # wrong!
409 will not, and a subsequent pop won't restore the correct attributes.
411 PUSHCOLOR pushes the attributes set by its argument, which is normally
412 a string of color constants. It can't ask the terminal what the
413 current attributes are.
414 Supporting CLICOLOR
416 <https://bixense.com/clicolors/> proposes a standard for enabling and
417 disabling color output from console commands using two environment
418 variables, CLICOLOR and CLICOLOR_FORCE. Term::ANSIColor cannot
419 automatically support this standard, since the correct action depends
420 on where the output is going and Term::ANSIColor may be used in a
421 context where colors should always be generated even if CLICOLOR is set
422 in the environment. But you can use the supported environment variable
423 ANSI_COLORS_DISABLED to implement CLICOLOR in your own programs with
424 code like this:
425 if (exists($ENV{CLICOLOR}) && $ENV{CLICOLOR} == 0) {
427 if (!$ENV{CLICOLOR_FORCE}) {
428 $ENV{ANSI_COLORS_DISABLED} = 1;
429 }
430 }
431 If you are using the constant interface, be sure to include this code
433 before you use any color constants (such as at the very top of your
434 script), since this environment variable is only honored the first time
435 a color constant is seen.
436 Be aware that this will export ANSI_COLORS_DISABLED to any child
438 processes of your program as well.
439
441 Bad color mapping %s
442 (W) The specified color mapping from ANSI_COLORS_ALIASES is not
443 valid and could not be parsed. It was ignored.
444 Bad escape sequence %s
446 (F) You passed an invalid ANSI escape sequence to uncolor().
447 Bareword "%s" not allowed while "strict subs" in use
449 (F) You probably mistyped a constant color name such as:
450 $Foobar = FOOBAR . "This line should be blue\n";
452 or:
454 @Foobar = FOOBAR, "This line should be blue\n";
456 This will only show up under use strict (another good reason to run
458 under use strict).
459 Cannot alias standard color %s
461 (F) The alias name passed to coloralias() matches a standard color
462 name. Standard color names cannot be aliased.
463 Cannot alias standard color %s in %s
465 (W) The same, but in ANSI_COLORS_ALIASES. The color mapping was
466 ignored.
467 Invalid alias name %s
469 (F) You passed an invalid alias name to coloralias(). Alias names
470 must consist only of alphanumerics, ".", "-", and "_".
471 Invalid alias name %s in %s
473 (W) You specified an invalid alias name on the left hand of the
474 equal sign in a color mapping in ANSI_COLORS_ALIASES. The color
475 mapping was ignored.
476 Invalid attribute name %s
478 (F) You passed an invalid attribute name to color(), colored(), or
479 coloralias().
480 Invalid attribute name %s in %s
482 (W) You specified an invalid attribute name on the right hand of
483 the equal sign in a color mapping in ANSI_COLORS_ALIASES. The
484 color mapping was ignored.
485 Name "%s" used only once: possible typo
487 (W) You probably mistyped a constant color name such as:
488 print FOOBAR "This text is color FOOBAR\n";
490 It's probably better to always use commas after constant names in
492 order to force the next error.
493 No comma allowed after filehandle
495 (F) You probably mistyped a constant color name such as:
496 print FOOBAR, "This text is color FOOBAR\n";
498 Generating this fatal compile error is one of the main advantages
500 of using the constants interface, since you'll immediately know if
501 you mistype a color name.
502 No name for escape sequence %s
504 (F) The ANSI escape sequence passed to uncolor() contains escapes
505 which aren't recognized and can't be translated to names.
506
508 ANSI_COLORS_ALIASES
509 This environment variable allows the user to specify custom color
510 aliases that will be understood by color(), colored(), and
511 colorvalid(). None of the other functions will be affected, and no
512 new color constants will be created. The custom colors are aliases
513 for existing color names; no new escape sequences can be
514 introduced. Only alphanumerics, ".", "_", and "-" are allowed in
515 alias names.
516 The format is:
518 ANSI_COLORS_ALIASES='newcolor1=oldcolor1,newcolor2=oldcolor2'
520 Whitespace is ignored. The alias value can be a single attribute
522 or a space-separated list of attributes.
523 For example the Solarized <https://ethanschoonover.com/solarized>
525 colors can be mapped with:
526 ANSI_COLORS_ALIASES='\
528 base00=bright_yellow, on_base00=on_bright_yellow,\
529 base01=bright_green, on_base01=on_bright_green, \
530 base02=black, on_base02=on_black, \
531 base03=bright_black, on_base03=on_bright_black, \
532 base0=bright_blue, on_base0=on_bright_blue, \
533 base1=bright_cyan, on_base1=on_bright_cyan, \
534 base2=white, on_base2=on_white, \
535 base3=bright_white, on_base3=on_bright_white, \
536 orange=bright_red, on_orange=on_bright_red, \
537 violet=bright_magenta,on_violet=on_bright_magenta'
538 This environment variable is read and applied when the
540 Term::ANSIColor module is loaded and is then subsequently ignored.
541 Changes to ANSI_COLORS_ALIASES after the module is loaded will have
542 no effect. See coloralias() for an equivalent facility that can be
543 used at runtime.
544 ANSI_COLORS_DISABLED
546 If this environment variable is set to a true value, all of the
547 functions defined by this module (color(), colored(), and all of
548 the constants) will not output any escape sequences and instead
549 will just return the empty string or pass through the original text
550 as appropriate. This is intended to support easy use of scripts
551 using this module on platforms that don't support ANSI escape
552 sequences.
553 NO_COLOR
555 If this environment variable is set to any value, it suppresses
556 generation of escape sequences the same as if ANSI_COLORS_DISABLED
557 is set to a true value. This implements the
558 <https://no-color.org/> informal standard. Programs that want to
559 enable color despite NO_COLOR being set will need to unset that
560 environment variable before any constant or function provided by
561 this module is used.
562
564 Term::ANSIColor was first included with Perl in Perl 5.6.0.
565 The uncolor() function and support for ANSI_COLORS_DISABLED were added
567 in Term::ANSIColor 1.04, included in Perl 5.8.0.
568 Support for dark was added in Term::ANSIColor 1.08, included in Perl
570 5.8.4.
571 The color stack, including the ":pushpop" import tag, PUSHCOLOR,
573 POPCOLOR, LOCALCOLOR, and the $Term::ANSIColor::AUTOLOCAL variable, was
574 added in Term::ANSIColor 2.00, included in Perl 5.10.1.
575 colorstrip() was added in Term::ANSIColor 2.01 and colorvalid() was
577 added in Term::ANSIColor 2.02, both included in Perl 5.11.0.
578 Support for colors 8 through 15 (the "bright_" variants) was added in
580 Term::ANSIColor 3.00, included in Perl 5.13.3.
581 Support for italic was added in Term::ANSIColor 3.02, included in Perl
583 5.17.1.
584 Support for colors 16 through 256 (the "ansi", "rgb", and "grey"
586 colors), the ":constants256" import tag, the coloralias() function, and
587 support for the ANSI_COLORS_ALIASES environment variable were added in
588 Term::ANSIColor 4.00, included in Perl 5.17.8.
589 $Term::ANSIColor::AUTOLOCAL was changed to take precedence over
591 $Term::ANSIColor::AUTORESET, rather than the other way around, in
592 Term::ANSIColor 4.00, included in Perl 5.17.8.
593 "ansi16" through "ansi255", as aliases for the "rgb" and "grey" colors,
595 and the corresponding "on_ansi" names and "ANSI" and "ON_ANSI"
596 constants were added in Term::ANSIColor 4.06, included in Perl 5.25.7.
597 Support for true color (the "rNNNgNNNbNNN" and "on_rNNNgNNNbNNN"
599 attributes), defining aliases in terms of other aliases, and aliases
600 mapping to multiple attributes instead of only a single attribute was
601 added in Term::ANSIColor 5.00.
602 Support for NO_COLOR was added in Term::ANSIColor 5.01.
604
606 Both colored() and many uses of the color constants will add the reset
607 escape sequence after a newline. If a program mixes colored output to
608 standard output with output to standard error, this can result in the
609 standard error text having the wrong color because the reset escape
610 sequence hasn't yet been flushed to the display (since standard output
611 to a terminal is line-buffered by default). To avoid this, either set
612 autoflush() on STDOUT or set $Term::ANSIColor::EACHLINE to "\n".
613 It would be nice if one could leave off the commas around the constants
615 entirely and just say:
616 print BOLD BLUE ON_WHITE "Text\n" RESET;
618 but the syntax of Perl doesn't allow this. You need a comma after the
620 string. (Of course, you may consider it a bug that commas between all
621 the constants aren't required, in which case you may feel free to
622 insert commas unless you're using $Term::ANSIColor::AUTORESET or
623 PUSHCOLOR/POPCOLOR.)
624 For easier debugging, you may prefer to always use the commas when not
626 setting $Term::ANSIColor::AUTORESET or PUSHCOLOR/POPCOLOR so that
627 you'll get a fatal compile error rather than a warning.
628 It's not possible to use this module to embed formatting and color
630 attributes using Perl formats. They replace the escape character with
631 a space (as documented in perlform(1)), resulting in garbled output
632 from the unrecognized attribute. Even if there were a way around that
633 problem, the format doesn't know that the non-printing escape sequence
634 is zero-length and would incorrectly format the output. For formatted
635 output using color or other attributes, either use sprintf() instead or
636 use formline() and then add the color or other attributes after
637 formatting and before output.
638
640 The codes generated by this module are standard terminal control codes,
641 complying with ECMA-048 and ISO 6429 (generally referred to as "ANSI
642 color" for the color codes). The non-color control codes (bold, dark,
643 italic, underline, and reverse) are part of the earlier ANSI X3.64
644 standard for control sequences for video terminals and peripherals.
645 Note that not all displays are ISO 6429-compliant, or even
647 X3.64-compliant (or are even attempting to be so). This module will
648 not work as expected on displays that do not honor these escape
649 sequences, such as cmd.exe, 4nt.exe, and command.com under either
650 Windows NT or Windows 2000. They may just be ignored, or they may
651 display as an ESC character followed by some apparent garbage.
652 Jean Delvare provided the following table of different common terminal
654 emulators and their support for the various attributes and others have
655 helped me flesh it out:
656 clear bold faint under blink reverse conceal
658 ------------------------------------------------------------------------
659 xterm yes yes no yes yes yes yes
660 linux yes yes yes bold yes yes no
661 rxvt yes yes no yes bold/black yes no
662 dtterm yes yes yes yes reverse yes yes
663 teraterm yes reverse no yes rev/red yes no
664 aixterm kinda normal no yes no yes yes
665 PuTTY yes color no yes no yes no
666 Windows yes no no no no yes no
667 Cygwin SSH yes yes no color color color yes
668 Terminal.app yes yes no yes yes yes yes
669 Windows is Windows telnet, Cygwin SSH is the OpenSSH implementation
671 under Cygwin on Windows NT, and Mac Terminal is the Terminal
672 application in Mac OS X. Where the entry is other than yes or no, that
673 emulator displays the given attribute as something else instead. Note
674 that on an aixterm, clear doesn't reset colors; you have to explicitly
675 set the colors back to what you want. More entries in this table are
676 welcome.
677 Support for code 3 (italic) is rare and therefore not mentioned in that
679 table. It is not believed to be fully supported by any of the
680 terminals listed, although it's displayed as green in the Linux
681 console, but it is reportedly supported by urxvt.
682 Note that codes 6 (rapid blink) and 9 (strike-through) are specified in
684 ANSI X3.64 and ECMA-048 but are not commonly supported by most displays
685 and emulators and therefore aren't supported by this module. ECMA-048
686 also specifies a large number of other attributes, including a sequence
687 of attributes for font changes, Fraktur characters, double-underlining,
688 framing, circling, and overlining. As none of these attributes are
689 widely supported or useful, they also aren't currently supported by
690 this module.
691 Most modern X terminal emulators support 256 colors. Known to not
693 support those colors are aterm, rxvt, Terminal.app, and TTY/VC.
694 For information on true color support in various terminal emulators,
696 see True Colour support <https://gist.github.com/XVilka/8346728>.
697
699 Original idea (using constants) by Zenin, reimplemented using subs by
700 Russ Allbery <rra@cpan.org>, and then combined with the original idea
701 by Russ with input from Zenin. 256-color support is based on work by
702 Kurt Starsinic. Russ Allbery now maintains this module.
703 PUSHCOLOR, POPCOLOR, and LOCALCOLOR were contributed by openmethods.com
705 voice solutions.
706
708 Copyright 1996-1998, 2000-2002, 2005-2006, 2008-2018, 2020 Russ Allbery
709 <rra@cpan.org>
710 Copyright 1996 Zenin
712 Copyright 2012 Kurt Starsinic <kstarsinic@gmail.com>
714 This program is free software; you may redistribute it and/or modify it
716 under the same terms as Perl itself.
717
719 The CPAN module Term::ExtendedColor provides a different and more
720 comprehensive interface for 256-color emulators that may be more
721 convenient. The CPAN module Win32::Console::ANSI provides ANSI color
722 (and other escape sequence) support in the Win32 Console environment.
723 The CPAN module Term::Chrome provides a different interface using
724 objects and operator overloading.
725 ECMA-048 is available on-line (at least at the time of this writing) at
727 <https://www.ecma-international.org/publications/standards/Ecma-048.htm>.
728 ISO 6429 is available from ISO for a charge; the author of this module
730 does not own a copy of it. Since the source material for ISO 6429 was
731 ECMA-048 and the latter is available for free, there seems little
732 reason to obtain the ISO standard.
733 The 256-color control sequences are documented at
735 <https://invisible-island.net/xterm/ctlseqs/ctlseqs.html> (search for
736 256-color).
737 Information about true color support in various terminal emulators and
739 test programs you can run to check the true color support in your
740 terminal emulator are available at
741 <https://gist.github.com/XVilka/8346728>.
742 CLICOLORS <https://bixense.com/clicolors/> and NO_COLOR <https://no-
744 color.org/> are useful standards to be aware of, and ideally follow,
745 for any application using color. Term::ANSIColor complies with the
746 latter.
747 The current version of this module is always available from its web
749 site at <https://www.eyrie.org/~eagle/software/ansicolor/>. It is also
750 part of the Perl core distribution as of 5.6.0.
751perl v5.30.1 2020-01-30 Term::ANSIColor(3)