|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 doesnt print it out, just returns it, so youll 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(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 youre 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 youll want to set $Term::ANSIColor::EACHLINE to "\n" to use this feature.
|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.|
|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.|
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";
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.)
Support for ITALIC was added in Term::ANSIColor 3.02.
When using the constants, if you dont 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 print the newline with a separate print statement to avoid confusing the terminal.
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. 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() wont 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.
As of Term::ANSIColor 2.0, 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.
When using PUSHCOLOR, POPCOLOR, and LOCALCOLOR, its 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 wont restore the correct attributes. PUSHCOLOR pushes the attributes set by its argument, which is normally a string of color constants. It cant ask the terminal what the current attributes are.
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";
@Foobar = FOOBAR, "This line should be blue\n";
Invalid attribute name %s (F) You passed an invalid attribute name to either color() or colored(). 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";
Its 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";
No name for escape sequence %s (F) The ANSI escape sequence passed to uncolor() contains escapes which arent recognized and cant be translated to names.
ANSI_COLORS_DISABLED If this environment variable is set, all of the functions defined by this module (color(), colored(), and all of the constants not previously used in the program) 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 dont support ANSI escape sequences.
For it to have its proper effect, this environment variable must be set before any color constants are used in the program.
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 doesnt allow this. You need a comma after the string. (Of course, you may consider it a bug that commas between all the constants arent required, in which case you may feel free to insert commas unless youre 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 youll get a fatal compile error rather than a warning.
Its 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 doesnt 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.
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 Mac Terminal 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 doesnt 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 its 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 arent supported by this module at the present time. 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 arent currently supported by this module.
ECMA-048 is available on-line (at least at the time of this writing) at <http://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.
Original idea (using constants) by Zenin, reimplemented using subs by Russ Allbery <email@example.com>, and then combined with the original idea by Russ with input from Zenin. Russ Allbery now maintains this module.
Copyright 1996, 1997, 1998, 2000, 2001, 2002, 2005, 2006, 2008, 2009, 2010, 2011, 2012 Russ Allbery <firstname.lastname@example.org> and Zenin. This program is free software; you may redistribute it and/or modify it under the same terms as Perl itself.
PUSHCOLOR, POPCOLOR, and LOCALCOLOR were contributed by openmethods.com voice solutions.
|perl v5.20.3||ANSICOLOR (3)||2012-03-18|