1Term::ANSIColor(3pm) Perl Programmers Reference Guide Term::ANSIColor(3pm)
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.';
17 print "\n";
18 use Term::ANSIColor qw(uncolor);
20 print uncolor '01;31', "\n";
21 use Term::ANSIColor qw(:constants);
23 print BOLD, BLUE, "This text is in bold blue.\n", RESET;
24 use Term::ANSIColor qw(:constants);
26 {
27 local $Term::ANSIColor::AUTORESET = 1;
28 print BOLD BLUE "This text is in bold blue.\n";
29 print "This text is normal.\n";
30 }
31 use Term::ANSIColor qw(:pushpop);
33 print PUSHCOLOR RED ON_GREEN "This text is red on green.\n";
34 print PUSHCOLOR BLUE "This text is blue on green.\n";
35 print RESET BLUE "This text is just blue.\n";
36 print POPCOLOR "Back to red on green.\n";
37 print LOCALCOLOR GREEN ON_BLUE "This text is green on blue.\n";
38 print "This text is red on green.\n";
39 {
40 local $Term::ANSIColor::AUTOLOCAL = 1;
41 print ON_BLUE "This text is red on blue.\n";
42 print "This text is red on green.\n";
43 }
44 print POPCOLOR "Back to whatever we started as.\n";
45
47 This module has two interfaces, one through color() and colored() and
48 the other through constants. It also offers the utility function
49 uncolor(), which has to be explicitly imported to be used (see
50 "SYNOPSIS").
51 color() takes any number of strings as arguments and considers them to
53 be space-separated lists of attributes. It then forms and returns the
54 escape sequence to set those attributes. It doesn't print it out, just
55 returns it, so you'll have to print it yourself if you want to (this is
56 so that you can save it as a string, pass it to something else, send it
57 to a file handle, or do anything else with it that you might care to).
58 uncolor() performs the opposite translation, turning escape sequences
60 into a list of strings.
61 The recognized non-color attributes are clear, reset, bold, dark,
63 faint, underline, underscore, blink, reverse, and concealed. Clear and
64 reset (reset to default attributes), dark and faint (dim and
65 saturated), and underline and underscore are equivalent, so use
66 whichever is the most intuitive to you. The recognized foreground
67 color attributes are black, red, green, yellow, blue, magenta, cyan,
68 and white. The recognized background color attributes are on_black,
69 on_red, on_green, on_yellow, on_blue, on_magenta, on_cyan, and
70 on_white. Case is not significant.
71 Note that not all attributes are supported by all terminal types, and
73 some terminals may not support any of these sequences. Dark and faint,
74 blink, and concealed in particular are frequently not implemented.
75 Attributes, once set, last until they are unset (by sending the
77 attribute "clear" or "reset"). Be careful to do this, or otherwise
78 your attribute will last after your script is done running, and people
79 get very annoyed at having their prompt and typing changed to weird
80 colors.
81 As an aid to help with this, colored() takes a scalar as the first
83 argument and any number of attribute strings as the second argument and
84 returns the scalar wrapped in escape codes so that the attributes will
85 be set as requested before the string and reset to normal after the
86 string. Alternately, you can pass a reference to an array as the first
87 argument, and then the contents of that array will be taken as
88 attributes and color codes and the remainder of the arguments as text
89 to colorize.
90 Normally, colored() just puts attribute codes at the beginning and end
92 of the string, but if you set $Term::ANSIColor::EACHLINE to some
93 string, that string will be considered the line delimiter and the
94 attribute will be set at the beginning of each line of the passed
95 string and reset at the end of each line. This is often desirable if
96 the output contains newlines and you're using background colors, since
97 a background color that persists across a newline is often interpreted
98 by the terminal as providing the default background color for the next
99 line. Programs like pagers can also be confused by attributes that
100 span lines. Normally you'll want to set $Term::ANSIColor::EACHLINE to
101 "\n" to use this feature.
102 Alternately, if you import ":constants", you can use the constants
104 CLEAR, RESET, BOLD, DARK, UNDERLINE, UNDERSCORE, BLINK, REVERSE,
105 CONCEALED, BLACK, RED, GREEN, YELLOW, BLUE, MAGENTA, CYAN, WHITE,
106 ON_BLACK, ON_RED, ON_GREEN, ON_YELLOW, ON_BLUE, ON_MAGENTA, ON_CYAN,
107 and ON_WHITE directly. These are the same as color('attribute') and
108 can be used if you prefer typing:
109 print BOLD BLUE ON_WHITE "Text", RESET, "\n";
111 to
113 print colored ("Text", 'bold blue on_white'), "\n";
115 (Note that the newline is kept separate to avoid confusing the terminal
117 as described above since a background color is being used.)
118 When using the constants, if you don't want to have to remember to add
120 the ", RESET" at the end of each print line, you can set
121 $Term::ANSIColor::AUTORESET to a true value. Then, the display mode
122 will automatically be reset if there is no comma after the constant.
123 In other words, with that variable set:
124 print BOLD BLUE "Text\n";
126 will reset the display mode afterward, whereas:
128 print BOLD, BLUE, "Text\n";
130 will not. If you are using background colors, you will probably want
132 to print the newline with a separate print statement to avoid confusing
133 the terminal.
134 The subroutine interface has the advantage over the constants interface
136 in that only two subroutines are exported into your namespace, versus
137 twenty-two in the constants interface. On the flip side, the constants
138 interface has the advantage of better compile time error checking,
139 since misspelled names of colors or attributes in calls to color() and
140 colored() won't be caught until runtime whereas misspelled names of
141 constants will be caught at compile time. So, pollute your namespace
142 with almost two dozen subroutines that you may not even use that often,
143 or risk a silly bug by mistyping an attribute. Your choice, TMTOWTDI
144 after all.
145 As of Term::ANSIColor 2.0, you can import ":pushpop" and maintain a
147 stack of colors using PUSHCOLOR, POPCOLOR, and LOCALCOLOR. PUSHCOLOR
148 takes the attribute string that starts its argument and pushes it onto
149 a stack of attributes. POPCOLOR removes the top of the stack and
150 restores the previous attributes set by the argument of a prior
151 PUSHCOLOR. LOCALCOLOR surrounds its argument in a PUSHCOLOR and
152 POPCOLOR so that the color resets afterward.
153 When using PUSHCOLOR, POPCOLOR, and LOCALCOLOR, it's particularly
155 important to not put commas between the constants.
156 print PUSHCOLOR BLUE "Text\n";
158 will correctly push BLUE onto the top of the stack.
160 print PUSHCOLOR, BLUE, "Text\n"; # wrong!
162 will not, and a subsequent pop won't restore the correct attributes.
164 PUSHCOLOR pushes the attributes set by its argument, which is normally
165 a string of color constants. It can't ask the terminal what the
166 current attributes are.
167
169 Bad escape sequence %s
170 (F) You passed an invalid ANSI escape sequence to uncolor().
171 Bareword "%s" not allowed while "strict subs" in use
173 (F) You probably mistyped a constant color name such as:
174 $Foobar = FOOBAR . "This line should be blue\n";
176 or:
178 @Foobar = FOOBAR, "This line should be blue\n";
180 This will only show up under use strict (another good reason to run
182 under use strict).
183 Invalid attribute name %s
185 (F) You passed an invalid attribute name to either color() or
186 colored().
187 Name "%s" used only once: possible typo
189 (W) You probably mistyped a constant color name such as:
190 print FOOBAR "This text is color FOOBAR\n";
192 It's probably better to always use commas after constant names in
194 order to force the next error.
195 No comma allowed after filehandle
197 (F) You probably mistyped a constant color name such as:
198 print FOOBAR, "This text is color FOOBAR\n";
200 Generating this fatal compile error is one of the main advantages
202 of using the constants interface, since you'll immediately know if
203 you mistype a color name.
204 No name for escape sequence %s
206 (F) The ANSI escape sequence passed to uncolor() contains escapes
207 which aren't recognized and can't be translated to names.
208
210 ANSI_COLORS_DISABLED
211 If this environment variable is set, all of the functions defined
212 by this module (color(), colored(), and all of the constants not
213 previously used in the program) will not output any escape
214 sequences and instead will just return the empty string or pass
215 through the original text as appropriate. This is intended to
216 support easy use of scripts using this module on platforms that
217 don't support ANSI escape sequences.
218 For it to have its proper effect, this environment variable must be
220 set before any color constants are used in the program.
221
223 It would be nice if one could leave off the commas around the constants
224 entirely and just say:
225 print BOLD BLUE ON_WHITE "Text\n" RESET;
227 but the syntax of Perl doesn't allow this. You need a comma after the
229 string. (Of course, you may consider it a bug that commas between all
230 the constants aren't required, in which case you may feel free to
231 insert commas unless you're using $Term::ANSIColor::AUTORESET or
232 PUSHCOLOR/POPCOLOR.)
233 For easier debugging, you may prefer to always use the commas when not
235 setting $Term::ANSIColor::AUTORESET or PUSHCOLOR/POPCOLOR so that
236 you'll get a fatal compile error rather than a warning.
237
239 The codes generated by this module are standard terminal control codes,
240 complying with ECMA-048 and ISO 6429 (generally referred to as "ANSI
241 color" for the color codes). The non-color control codes (bold, dark,
242 italic, underline, and reverse) are part of the earlier ANSI X3.64
243 standard for control sequences for video terminals and peripherals.
244 Note that not all displays are ISO 6429-compliant, or even
246 X3.64-compliant (or are even attempting to be so). This module will
247 not work as expected on displays that do not honor these escape
248 sequences, such as cmd.exe, 4nt.exe, and command.com under either
249 Windows NT or Windows 2000. They may just be ignored, or they may
250 display as an ESC character followed by some apparent garbage.
251 Jean Delvare provided the following table of different common terminal
253 emulators and their support for the various attributes and others have
254 helped me flesh it out:
255 clear bold faint under blink reverse conceal
257 ------------------------------------------------------------------------
258 xterm yes yes no yes bold yes yes
259 linux yes yes yes bold yes yes no
260 rxvt yes yes no yes bold/black yes no
261 dtterm yes yes yes yes reverse yes yes
262 teraterm yes reverse no yes rev/red yes no
263 aixterm kinda normal no yes no yes yes
264 PuTTY yes color no yes no yes no
265 Windows yes no no no no yes no
266 Cygwin SSH yes yes no color color color yes
267 Mac Terminal yes yes no yes yes yes yes
268 Windows is Windows telnet, Cygwin SSH is the OpenSSH implementation
270 under Cygwin on Windows NT, and Mac Terminal is the Terminal
271 application in Mac OS X. Where the entry is other than yes or no, that
272 emulator displays the given attribute as something else instead. Note
273 that on an aixterm, clear doesn't reset colors; you have to explicitly
274 set the colors back to what you want. More entries in this table are
275 welcome.
276 Note that codes 3 (italic), 6 (rapid blink), and 9 (strike-through) are
278 specified in ANSI X3.64 and ECMA-048 but are not commonly supported by
279 most displays and emulators and therefore aren't supported by this
280 module at the present time. ECMA-048 also specifies a large number of
281 other attributes, including a sequence of attributes for font changes,
282 Fraktur characters, double-underlining, framing, circling, and
283 overlining. As none of these attributes are widely supported or
284 useful, they also aren't currently supported by this module.
285
287 ECMA-048 is available on-line (at least at the time of this writing) at
288 <http://www.ecma-international.org/publications/standards/ECMA-048.HTM>.
289 ISO 6429 is available from ISO for a charge; the author of this module
291 does not own a copy of it. Since the source material for ISO 6429 was
292 ECMA-048 and the latter is available for free, there seems little
293 reason to obtain the ISO standard.
294 The current version of this module is always available from its web
296 site at <http://www.eyrie.org/~eagle/software/ansicolor/>. It is also
297 part of the Perl core distribution as of 5.6.0.
298
300 Original idea (using constants) by Zenin, reimplemented using subs by
301 Russ Allbery <rra@stanford.edu>, and then combined with the original
302 idea by Russ with input from Zenin. Russ Allbery now maintains this
303 module.
304
306 Copyright 1996, 1997, 1998, 2000, 2001, 2002, 2005, 2006, 2008, 2009
307 Russ Allbery <rra@stanford.edu> and Zenin. This program is free
308 software; you may redistribute it and/or modify it under the same terms
309 as Perl itself.
310 PUSHCOLOR, POPCOLOR, and LOCALCOLOR were contributed by openmethods.com
312 voice solutions.
313perl v5.10.1 2009-04-15 Term::ANSIColor(3pm)