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   1  # Term::ANSIColor -- Color screen output using ANSI escape sequences.
   2  # $Id: ANSIColor.pm 64 2007-03-23 17:58:18Z eagle $
   3  #
   4  # Copyright 1996, 1997, 1998, 2000, 2001, 2002, 2005, 2006
   5  #   by Russ Allbery <rra@stanford.edu> and Zenin
   6  #
   7  # This program is free software; you may redistribute it and/or modify it
   8  # under the same terms as Perl itself.
   9  #
  10  # Ah, September, when the sysadmins turn colors and fall off the trees....
  11  #                               -- Dave Van Domelen
  12  
  13  ##############################################################################
  14  # Modules and declarations
  15  ##############################################################################
  16  
  17  package Term::ANSIColor;
  18  require 5.001;
  19  
  20  use strict;
  21  use vars qw($AUTOLOAD $AUTORESET $EACHLINE @ISA @EXPORT @EXPORT_OK
  22              %EXPORT_TAGS $VERSION %attributes %attributes_r);
  23  
  24  use Exporter ();
  25  @ISA         = qw(Exporter);
  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
  32                                   ON_CYAN ON_WHITE)]);
  33  Exporter::export_ok_tags ('constants');
  34  
  35  $VERSION = '1.12';
  36  
  37  ##############################################################################
  38  # Internal data structures
  39  ##############################################################################
  40  
  41  %attributes = ('clear'      => 0,
  42                 'reset'      => 0,
  43                 'bold'       => 1,
  44                 'dark'       => 2,
  45                 'underline'  => 4,
  46                 'underscore' => 4,
  47                 'blink'      => 5,
  48                 'reverse'    => 7,
  49                 'concealed'  => 8,
  50  
  51                 'black'      => 30,   'on_black'   => 40,
  52                 'red'        => 31,   'on_red'     => 41,
  53                 'green'      => 32,   'on_green'   => 42,
  54                 'yellow'     => 33,   'on_yellow'  => 43,
  55                 'blue'       => 34,   'on_blue'    => 44,
  56                 'magenta'    => 35,   'on_magenta' => 45,
  57                 'cyan'       => 36,   'on_cyan'    => 46,
  58                 'white'      => 37,   'on_white'   => 47);
  59  
  60  # Reverse lookup.  Alphabetically first name for a sequence is preferred.
  61  for (reverse sort keys %attributes) {
  62      $attributes_r{$attributes{$_}} = $_;
  63  }
  64  
  65  ##############################################################################
  66  # Implementation (constant form)
  67  ##############################################################################
  68  
  69  # Time to have fun!  We now want to define the constant subs, which are named
  70  # the same as the attributes above but in all caps.  Each constant sub needs
  71  # to act differently depending on whether $AUTORESET is set.  Without
  72  # autoreset:
  73  #
  74  #     BLUE "text\n"  ==>  "\e[34mtext\n"
  75  #
  76  # If $AUTORESET is set, we should instead get:
  77  #
  78  #     BLUE "text\n"  ==>  "\e[34mtext\n\e[0m"
  79  #
  80  # The sub also needs to handle the case where it has no arguments correctly.
  81  # Maintaining all of this as separate subs would be a major nightmare, as well
  82  # as duplicate the %attributes hash, so instead we define an AUTOLOAD sub to
  83  # define the constant subs on demand.  To do that, we check the name of the
  84  # called sub against the list of attributes, and if it's an all-caps version
  85  # of one of them, we define the sub on the fly and then run it.
  86  #
  87  # If the environment variable ANSI_COLORS_DISABLED is set, turn all of the
  88  # generated subs into pass-through functions that don't add any escape
  89  # sequences.  This is to make it easier to write scripts that also work on
  90  # systems without any ANSI support, like Windows consoles.
  91  sub AUTOLOAD {
  92      my $enable_colors = !defined $ENV{ANSI_COLORS_DISABLED};
  93      my $sub;
  94      ($sub = $AUTOLOAD) =~ s/^.*:://;
  95      my $attr = $attributes{lc $sub};
  96      if ($sub =~ /^[A-Z_]+$/ && defined $attr) {
  97          $attr = $enable_colors ? "\e[" . $attr . 'm' : '';
  98          eval qq {
  99              sub $AUTOLOAD {
 100                  if (\$AUTORESET && \@_) {
 101                      '$attr' . "\@_" . "\e[0m";
 102                  } else {
 103                      ('$attr' . "\@_");
 104                  }
 105              }
 106          };
 107          goto &$AUTOLOAD;
 108      } else {
 109          require Carp;
 110          Carp::croak ("undefined subroutine &$AUTOLOAD called");
 111      }
 112  }
 113  
 114  ##############################################################################
 115  # Implementation (attribute string form)
 116  ##############################################################################
 117  
 118  # Return the escape code for a given set of color attributes.
 119  sub color {
 120      return '' if defined $ENV{ANSI_COLORS_DISABLED};
 121      my @codes = map { split } @_;
 122      my $attribute = '';
 123      foreach (@codes) {
 124          $_ = lc $_;
 125          unless (defined $attributes{$_}) {
 126              require Carp;
 127              Carp::croak ("Invalid attribute name $_");
 128          }
 129          $attribute .= $attributes{$_} . ';';
 130      }
 131      chop $attribute;
 132      ($attribute ne '') ? "\e[$attribute}m" : undef;
 133  }
 134  
 135  # Return a list of named color attributes for a given set of escape codes.
 136  # Escape sequences can be given with or without enclosing "\e[" and "m".  The
 137  # empty escape sequence '' or "\e[m" gives an empty list of attrs.
 138  sub uncolor {
 139      my (@nums, @result);
 140      for (@_) {
 141          my $escape = $_;
 142          $escape =~ s/^\e\[//;
 143          $escape =~ s/m$//;
 144          unless ($escape =~ /^((?:\d+;)*\d*)$/) {
 145              require Carp;
 146              Carp::croak ("Bad escape sequence $_");
 147          }
 148          push (@nums, split (/;/, $1));
 149      }
 150      for (@nums) {
 151      $_ += 0; # Strip leading zeroes
 152      my $name = $attributes_r{$_};
 153      if (!defined $name) {
 154          require Carp;
 155          Carp::croak ("No name for escape sequence $_" );
 156      }
 157      push (@result, $name);
 158      }
 159      @result;
 160  }
 161  
 162  # Given a string and a set of attributes, returns the string surrounded by
 163  # escape codes to set those attributes and then clear them at the end of the
 164  # string.  The attributes can be given either as an array ref as the first
 165  # argument or as a list as the second and subsequent arguments.  If $EACHLINE
 166  # is set, insert a reset before each occurrence of the string $EACHLINE and
 167  # the starting attribute code after the string $EACHLINE, so that no attribute
 168  # crosses line delimiters (this is often desirable if the output is to be
 169  # piped to a pager or some other program).
 170  sub colored {
 171      my ($string, @codes);
 172      if (ref $_[0]) {
 173          @codes = @{+shift};
 174          $string = join ('', @_);
 175      } else {
 176          $string = shift;
 177          @codes = @_;
 178      }
 179      return $string if defined $ENV{ANSI_COLORS_DISABLED};
 180      if (defined $EACHLINE) {
 181          my $attr = color (@codes);
 182          join '',
 183              map { $_ ne $EACHLINE ? $attr . $_ . "\e[0m" : $_ }
 184                  grep { length ($_) > 0 }
 185                      split (/(\Q$EACHLINE\E)/, $string);
 186      } else {
 187          color (@codes) . $string . "\e[0m";
 188      }
 189  }
 190  
 191  ##############################################################################
 192  # Module return value and documentation
 193  ##############################################################################
 194  
 195  # Ensure we evaluate to true.
 196  1;
 197  __END__
 198  
 199  =head1 NAME
 200  
 201  Term::ANSIColor - Color screen output using ANSI escape sequences
 202  
 203  =head1 SYNOPSIS
 204  
 205      use Term::ANSIColor;
 206      print color 'bold blue';
 207      print "This text is bold blue.\n";
 208      print color 'reset';
 209      print "This text is normal.\n";
 210      print colored ("Yellow on magenta.", 'yellow on_magenta'), "\n";
 211      print "This text is normal.\n";
 212      print colored ['yellow on_magenta'], 'Yellow on magenta.';
 213      print "\n";
 214  
 215      use Term::ANSIColor qw(uncolor);
 216      print uncolor '01;31', "\n";
 217  
 218      use Term::ANSIColor qw(:constants);
 219      print BOLD, BLUE, "This text is in bold blue.\n", RESET;
 220  
 221      use Term::ANSIColor qw(:constants);
 222      $Term::ANSIColor::AUTORESET = 1;
 223      print BOLD BLUE "This text is in bold blue.\n";
 224      print "This text is normal.\n";
 225  
 226  =head1 DESCRIPTION
 227  
 228  This module has two interfaces, one through color() and colored() and the
 229  other through constants.  It also offers the utility function uncolor(),
 230  which has to be explicitly imported to be used (see L</SYNOPSIS>).
 231  
 232  color() takes any number of strings as arguments and considers them to be
 233  space-separated lists of attributes.  It then forms and returns the escape
 234  sequence to set those attributes.  It doesn't print it out, just returns it,
 235  so you'll have to print it yourself if you want to (this is so that you can
 236  save it as a string, pass it to something else, send it to a file handle, or
 237  do anything else with it that you might care to).
 238  
 239  uncolor() performs the opposite translation, turning escape sequences
 240  into a list of strings.
 241  
 242  The recognized attributes (all of which should be fairly intuitive) are clear,
 243  reset, dark, bold, underline, underscore, blink, reverse, concealed, black,
 244  red, green, yellow, blue, magenta, cyan, white, on_black, on_red, on_green,
 245  on_yellow, on_blue, on_magenta, on_cyan, and on_white.  Case is not
 246  significant.  Underline and underscore are equivalent, as are clear and reset,
 247  so use whichever is the most intuitive to you.  The color alone sets the
 248  foreground color, and on_color sets the background color.
 249  
 250  Note that not all attributes are supported by all terminal types, and some
 251  terminals may not support any of these sequences.  Dark, blink, and
 252  concealed in particular are frequently not implemented.
 253  
 254  Attributes, once set, last until they are unset (by sending the attribute
 255  "reset").  Be careful to do this, or otherwise your attribute will last
 256  after your script is done running, and people get very annoyed at having
 257  their prompt and typing changed to weird colors.
 258  
 259  As an aid to help with this, colored() takes a scalar as the first argument
 260  and any number of attribute strings as the second argument and returns the
 261  scalar wrapped in escape codes so that the attributes will be set as
 262  requested before the string and reset to normal after the string.
 263  Alternately, you can pass a reference to an array as the first argument, and
 264  then the contents of that array will be taken as attributes and color codes
 265  and the remainder of the arguments as text to colorize.
 266  
 267  Normally, colored() just puts attribute codes at the beginning and end of
 268  the string, but if you set $Term::ANSIColor::EACHLINE to some string, that
 269  string will be considered the line delimiter and the attribute will be set
 270  at the beginning of each line of the passed string and reset at the end of
 271  each line.  This is often desirable if the output contains newlines and
 272  you're using background colors, since a background color that persists
 273  across a newline is often interpreted by the terminal as providing the
 274  default background color for the next line.  Programs like pagers can also
 275  be confused by attributes that span lines.  Normally you'll want to set
 276  $Term::ANSIColor::EACHLINE to C<"\n"> to use this feature.
 277  
 278  Alternately, if you import C<:constants>, you can use the constants CLEAR,
 279  RESET, BOLD, DARK, UNDERLINE, UNDERSCORE, BLINK, REVERSE, CONCEALED, BLACK,
 280  RED, GREEN, YELLOW, BLUE, MAGENTA, CYAN, WHITE, ON_BLACK, ON_RED, ON_GREEN,
 281  ON_YELLOW, ON_BLUE, ON_MAGENTA, ON_CYAN, and ON_WHITE directly.  These are
 282  the same as color('attribute') and can be used if you prefer typing:
 283  
 284      print BOLD BLUE ON_WHITE "Text", RESET, "\n";
 285  
 286  to
 287  
 288      print colored ("Text", 'bold blue on_white'), "\n";
 289  
 290  (Note that the newline is kept separate to avoid confusing the terminal as
 291  described above since a background color is being used.)
 292  
 293  When using the constants, if you don't want to have to remember to add the
 294  C<, RESET> at the end of each print line, you can set
 295  $Term::ANSIColor::AUTORESET to a true value.  Then, the display mode will
 296  automatically be reset if there is no comma after the constant.  In other
 297  words, with that variable set:
 298  
 299      print BOLD BLUE "Text\n";
 300  
 301  will reset the display mode afterwards, whereas:
 302  
 303      print BOLD, BLUE, "Text\n";
 304  
 305  will not.  If you are using background colors, you will probably want to
 306  print the newline with a separate print statement to avoid confusing the
 307  terminal.
 308  
 309  The subroutine interface has the advantage over the constants interface in
 310  that only two subroutines are exported into your namespace, versus
 311  twenty-two in the constants interface.  On the flip side, the constants
 312  interface has the advantage of better compile time error checking, since
 313  misspelled names of colors or attributes in calls to color() and colored()
 314  won't be caught until runtime whereas misspelled names of constants will be
 315  caught at compile time.  So, pollute your namespace with almost two dozen
 316  subroutines that you may not even use that often, or risk a silly bug by
 317  mistyping an attribute.  Your choice, TMTOWTDI after all.
 318  
 319  =head1 DIAGNOSTICS
 320  
 321  =over 4
 322  
 323  =item Bad escape sequence %s
 324  
 325  (F) You passed an invalid ANSI escape sequence to uncolor().
 326  
 327  =item Bareword "%s" not allowed while "strict subs" in use
 328  
 329  (F) You probably mistyped a constant color name such as:
 330  
 331      $Foobar = FOOBAR . "This line should be blue\n";
 332  
 333  or:
 334  
 335      @Foobar = FOOBAR, "This line should be blue\n";
 336  
 337  This will only show up under use strict (another good reason to run under
 338  use strict).
 339  
 340  =item Invalid attribute name %s
 341  
 342  (F) You passed an invalid attribute name to either color() or colored().
 343  
 344  =item Name "%s" used only once: possible typo
 345  
 346  (W) You probably mistyped a constant color name such as:
 347  
 348      print FOOBAR "This text is color FOOBAR\n";
 349  
 350  It's probably better to always use commas after constant names in order to
 351  force the next error.
 352  
 353  =item No comma allowed after filehandle
 354  
 355  (F) You probably mistyped a constant color name such as:
 356  
 357      print FOOBAR, "This text is color FOOBAR\n";
 358  
 359  Generating this fatal compile error is one of the main advantages of using
 360  the constants interface, since you'll immediately know if you mistype a
 361  color name.
 362  
 363  =item No name for escape sequence %s
 364  
 365  (F) The ANSI escape sequence passed to uncolor() contains escapes which
 366  aren't recognized and can't be translated to names.
 367  
 368  =back
 369  
 370  =head1 ENVIRONMENT
 371  
 372  =over 4
 373  
 374  =item ANSI_COLORS_DISABLED
 375  
 376  If this environment variable is set, all of the functions defined by this
 377  module (color(), colored(), and all of the constants not previously used in
 378  the program) will not output any escape sequences and instead will just
 379  return the empty string or pass through the original text as appropriate.
 380  This is intended to support easy use of scripts using this module on
 381  platforms that don't support ANSI escape sequences.
 382  
 383  For it to have its proper effect, this environment variable must be set
 384  before any color constants are used in the program.
 385  
 386  =back
 387  
 388  =head1 RESTRICTIONS
 389  
 390  It would be nice if one could leave off the commas around the constants
 391  entirely and just say:
 392  
 393      print BOLD BLUE ON_WHITE "Text\n" RESET;
 394  
 395  but the syntax of Perl doesn't allow this.  You need a comma after the
 396  string.  (Of course, you may consider it a bug that commas between all the
 397  constants aren't required, in which case you may feel free to insert commas
 398  unless you're using $Term::ANSIColor::AUTORESET.)
 399  
 400  For easier debugging, you may prefer to always use the commas when not
 401  setting $Term::ANSIColor::AUTORESET so that you'll get a fatal compile error
 402  rather than a warning.
 403  
 404  =head1 NOTES
 405  
 406  The codes generated by this module are standard terminal control codes,
 407  complying with ECMA-48 and ISO 6429 (generally referred to as "ANSI color"
 408  for the color codes).  The non-color control codes (bold, dark, italic,
 409  underline, and reverse) are part of the earlier ANSI X3.64 standard for
 410  control sequences for video terminals and peripherals.
 411  
 412  Note that not all displays are ISO 6429-compliant, or even X3.64-compliant
 413  (or are even attempting to be so).  This module will not work as expected on
 414  displays that do not honor these escape sequences, such as cmd.exe, 4nt.exe,
 415  and command.com under either Windows NT or Windows 2000.  They may just be
 416  ignored, or they may display as an ESC character followed by some apparent
 417  garbage.
 418  
 419  Jean Delvare provided the following table of different common terminal
 420  emulators and their support for the various attributes and others have helped
 421  me flesh it out:
 422  
 423                clear    bold     dark    under    blink   reverse  conceal
 424   ------------------------------------------------------------------------
 425   xterm         yes      yes      no      yes     bold      yes      yes
 426   linux         yes      yes      yes    bold      yes      yes      no
 427   rxvt          yes      yes      no      yes  bold/black   yes      no
 428   dtterm        yes      yes      yes     yes    reverse    yes      yes
 429   teraterm      yes    reverse    no      yes    rev/red    yes      no
 430   aixterm      kinda   normal     no      yes      no       yes      yes
 431   PuTTY         yes     color     no      yes      no       yes      no
 432   Windows       yes      no       no      no       no       yes      no
 433   Cygwin SSH    yes      yes      no     color    color    color     yes
 434   Mac Terminal  yes      yes      no      yes      yes      yes      yes
 435  
 436  Windows is Windows telnet, Cygwin SSH is the OpenSSH implementation under
 437  Cygwin on Windows NT, and Mac Terminal is the Terminal application in Mac OS
 438  X.  Where the entry is other than yes or no, that emulator displays the
 439  given attribute as something else instead.  Note that on an aixterm, clear
 440  doesn't reset colors; you have to explicitly set the colors back to what you
 441  want.  More entries in this table are welcome.
 442  
 443  Note that codes 3 (italic), 6 (rapid blink), and 9 (strikethrough) are
 444  specified in ANSI X3.64 and ECMA-048 but are not commonly supported by most
 445  displays and emulators and therefore aren't supported by this module at the
 446  present time.  ECMA-048 also specifies a large number of other attributes,
 447  including a sequence of attributes for font changes, Fraktur characters,
 448  double-underlining, framing, circling, and overlining.  As none of these
 449  attributes are widely supported or useful, they also aren't currently
 450  supported by this module.
 451  
 452  =head1 SEE ALSO
 453  
 454  ECMA-048 is available on-line (at least at the time of this writing) at
 455  L<http://www.ecma-international.org/publications/standards/ECMA-048.HTM>.
 456  
 457  ISO 6429 is available from ISO for a charge; the author of this module does
 458  not own a copy of it.  Since the source material for ISO 6429 was ECMA-048
 459  and the latter is available for free, there seems little reason to obtain
 460  the ISO standard.
 461  
 462  The current version of this module is always available from its web site at
 463  L<http://www.eyrie.org/~eagle/software/ansicolor/>.  It is also part of the
 464  Perl core distribution as of 5.6.0.
 465  
 466  =head1 AUTHORS
 467  
 468  Original idea (using constants) by Zenin, reimplemented using subs by Russ
 469  Allbery <rra@stanford.edu>, and then combined with the original idea by Russ
 470  with input from Zenin.  Russ Allbery now maintains this module.
 471  
 472  =head1 COPYRIGHT AND LICENSE
 473  
 474  Copyright 1996, 1997, 1998, 2000, 2001, 2002, 2005, 2006 Russ Allbery
 475  <rra@stanford.edu> and Zenin.  This program is free software; you may
 476  redistribute it and/or modify it under the same terms as Perl itself.
 477  
 478  =cut