lib/perl5/5.6.1/Term/ANSIColor.pm

   1 # Term::ANSIColor -- Color screen output using ANSI escape sequences.
   2 # $Id: ANSIColor.pm,v 1.3 2000/08/06 18:28:10 eagle Exp $
   3 #
   4 # Copyright 1996, 1997, 1998, 2000
   5 #   by Russ Allbery <rra@stanford.edu> and Zenin <zenin@best.com>
   6 #
   7 # This program is free software; you can 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(@ISA @EXPORT %EXPORT_TAGS $VERSION $AUTOLOAD %attributes
  22             $AUTORESET $EACHLINE);
  23
  24 use Exporter ();
  25 @ISA         = qw(Exporter);
  26 @EXPORT      = qw(color colored);
  27 %EXPORT_TAGS = (constants => [qw(CLEAR RESET BOLD UNDERLINE UNDERSCORE BLINK
  28                                  REVERSE CONCEALED BLACK RED GREEN YELLOW
  29                                  BLUE MAGENTA CYAN WHITE ON_BLACK ON_RED
  30                                  ON_GREEN ON_YELLOW ON_BLUE ON_MAGENTA
  31                                  ON_CYAN ON_WHITE)]);
  32 Exporter::export_ok_tags ('constants');
  33
  34 # Don't use the CVS revision as the version, since this module is also in
  35 # Perl core and too many things could munge CVS magic revision strings.
  36 $VERSION = 1.03;
  37
  38
  39 ############################################################################
  40 # Internal data structures
  41 ############################################################################
  42
  43 %attributes = ('clear'      => 0,
  44                'reset'      => 0,
  45                'bold'       => 1,
  46                'dark'       => 2,
  47                'underline'  => 4,
  48                'underscore' => 4,
  49                'blink'      => 5,
  50                'reverse'    => 7,
  51                'concealed'  => 8,
  52
  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);
  61
  62
  63 ############################################################################
  64 # Implementation (constant form)
  65 ############################################################################
  66
  67 # Time to have fun!  We now want to define the constant subs, which are
  68 # named the same as the attributes above but in all caps.  Each constant sub
  69 # needs to act differently depending on whether $AUTORESET is set.  Without
  70 # autoreset:
  71 #
  72 #   BLUE "text\n"  ==>  "\e[34mtext\n"
  73 #
  74 # If $AUTORESET is set, we should instead get:
  75 #
  76 #   BLUE "text\n"  ==>  "\e[34mtext\n\e[0m"
  77 #
  78 # The sub also needs to handle the case where it has no arguments correctly.
  79 # Maintaining all of this as separate subs would be a major nightmare, as
  80 # well as duplicate the %attributes hash, so instead we define an AUTOLOAD
  81 # sub to define the constant subs on demand.  To do that, we check the name
  82 # of the called sub against the list of attributes, and if it's an all-caps
  83 # version of one of them, we define the sub on the fly and then run it.
  84 sub AUTOLOAD {
  85     my $sub;
  86     ($sub = $AUTOLOAD) =~ s/^.*:://;
  87     my $attr = $attributes{lc $sub};
  88     if ($sub =~ /^[A-Z_]+$/ && defined $attr) {
  89         $attr = "\e[" . $attr . 'm';
  90         eval qq {
  91             sub $AUTOLOAD {
  92                 if (\$AUTORESET && \@_) {
  93                     '$attr' . "\@_" . "\e[0m";
  94                 } else {
  95                     ('$attr' . "\@_");
  96                 }
  97             }
  98         };
  99         goto &$AUTOLOAD;
 100     } else {
 101         require Carp;
 102         Carp::croak ("undefined subroutine &$AUTOLOAD called");
 103     }
 104 }
 105
 106
 107 ############################################################################
 108 # Implementation (attribute string form)
 109 ############################################################################
 110
 111 # Return the escape code for a given set of color attributes.
 112 sub color {
 113     my @codes = map { split } @_;
 114     my $attribute = '';
 115     foreach (@codes) {
 116         $_ = lc $_;
 117         unless (defined $attributes{$_}) {
 118             require Carp;
 119             Carp::croak ("Invalid attribute name $_");
 120         }
 121         $attribute .= $attributes{$_} . ';';
 122     }
 123     chop $attribute;
 124     ($attribute ne '') ? "\e[${attribute}m" : undef;
 125 }
 126
 127 # Given a string and a set of attributes, returns the string surrounded by
 128 # escape codes to set those attributes and then clear them at the end of the
 129 # string.  The attributes can be given either as an array ref as the first
 130 # argument or as a list as the second and subsequent arguments.  If
 131 # $EACHLINE is set, insert a reset before each occurrence of the string
 132 # $EACHLINE and the starting attribute code after the string $EACHLINE, so
 133 # that no attribute crosses line delimiters (this is often desirable if the
 134 # output is to be piped to a pager or some other program).
 135 sub colored {
 136     my ($string, @codes);
 137     if (ref $_[0]) {
 138         @codes = @{+shift};
 139         $string = join ('', @_);
 140     } else {
 141         $string = shift;
 142         @codes = @_;
 143     }
 144     if (defined $EACHLINE) {
 145         my $attr = color (@codes);
 146         join '',
 147             map { $_ && $_ ne $EACHLINE ? $attr . $_ . "\e[0m" : $_ }
 148                 split (/(\Q$EACHLINE\E)/, $string);
 149     } else {
 150         color (@codes) . $string . "\e[0m";
 151     }
 152 }
 153
 154
 155 ############################################################################
 156 # Module return value and documentation
 157 ############################################################################
 158
 159 # Ensure we evaluate to true.
 160 1;
 161 __END__
 162
 163 =head1 NAME
 164
 165 Term::ANSIColor - Color screen output using ANSI escape sequences
 166
 167 =head1 SYNOPSIS
 168
 169     use Term::ANSIColor;
 170     print color 'bold blue';
 171     print "This text is bold blue.\n";
 172     print color 'reset';
 173     print "This text is normal.\n";
 174     print colored ("Yellow on magenta.\n", 'yellow on_magenta');
 175     print "This text is normal.\n";
 176     print colored ['yellow on_magenta'], "Yellow on magenta.\n";
 177
 178     use Term::ANSIColor qw(:constants);
 179     print BOLD, BLUE, "This text is in bold blue.\n", RESET;
 180
 181     use Term::ANSIColor qw(:constants);
 182     $Term::ANSIColor::AUTORESET = 1;
 183     print BOLD BLUE "This text is in bold blue.\n";
 184     print "This text is normal.\n";
 185
 186 =head1 DESCRIPTION
 187
 188 This module has two interfaces, one through color() and colored() and the
 189 other through constants.
 190
 191 color() takes any number of strings as arguments and considers them to be
 192 space-separated lists of attributes.  It then forms and returns the escape
 193 sequence to set those attributes.  It doesn't print it out, just returns
 194 it, so you'll have to print it yourself if you want to (this is so that
 195 you can save it as a string, pass it to something else, send it to a file
 196 handle, or do anything else with it that you might care to).
 197
 198 The recognized attributes (all of which should be fairly intuitive) are
 199 clear, reset, dark, bold, underline, underscore, blink, reverse,
 200 concealed, black, red, green, yellow, blue, magenta, on_black, on_red,
 201 on_green, on_yellow, on_blue, on_magenta, on_cyan, and on_white.  Case is
 202 not significant.  Underline and underscore are equivalent, as are clear
 203 and reset, so use whichever is the most intuitive to you.  The color alone
 204 sets the foreground color, and on_color sets the background color.
 205
 206 Note that not all attributes are supported by all terminal types, and some
 207 terminals may not support any of these sequences.  Dark, blink, and
 208 concealed in particular are frequently not implemented.
 209
 210 Attributes, once set, last until they are unset (by sending the attribute
 211 "reset").  Be careful to do this, or otherwise your attribute will last
 212 after your script is done running, and people get very annoyed at having
 213 their prompt and typing changed to weird colors.
 214
 215 As an aid to help with this, colored() takes a scalar as the first
 216 argument and any number of attribute strings as the second argument and
 217 returns the scalar wrapped in escape codes so that the attributes will be
 218 set as requested before the string and reset to normal after the string.
 219 Alternately, you can pass a reference to an array as the first argument,
 220 and then the contents of that array will be taken as attributes and color
 221 codes and the remainder of the arguments as text to colorize.
 222
 223 Normally, colored() just puts attribute codes at the beginning and end of
 224 the string, but if you set $Term::ANSIColor::EACHLINE to some string,
 225 that string will be considered the line delimiter and the attribute will
 226 be set at the beginning of each line of the passed string and reset at the
 227 end of each line.  This is often desirable if the output is being sent to
 228 a program like a pager that can be confused by attributes that span lines.
 229 Normally you'll want to set $Term::ANSIColor::EACHLINE to C<"\n"> to use
 230 this feature.
 231
 232 Alternately, if you import C<:constants>, you can use the constants CLEAR,
 233 RESET, BOLD, DARK, UNDERLINE, UNDERSCORE, BLINK, REVERSE, CONCEALED,
 234 BLACK, RED, GREEN, YELLOW, BLUE, MAGENTA, ON_BLACK, ON_RED, ON_GREEN,
 235 ON_YELLOW, ON_BLUE, ON_MAGENTA, ON_CYAN, and ON_WHITE directly.  These are
 236 the same as color('attribute') and can be used if you prefer typing:
 237
 238     print BOLD BLUE ON_WHITE "Text\n", RESET;
 239
 240 to
 241
 242     print colored ("Text\n", 'bold blue on_white');
 243
 244 When using the constants, if you don't want to have to remember to add the
 245 C<, RESET> at the end of each print line, you can set
 246 $Term::ANSIColor::AUTORESET to a true value.  Then, the display mode will
 247 automatically be reset if there is no comma after the constant.  In other
 248 words, with that variable set:
 249
 250     print BOLD BLUE "Text\n";
 251
 252 will reset the display mode afterwards, whereas:
 253
 254     print BOLD, BLUE, "Text\n";
 255
 256 will not.
 257
 258 The subroutine interface has the advantage over the constants interface in
 259 that only two subroutines are exported into your namespace, versus
 260 twenty-two in the constants interface.  On the flip side, the constants
 261 interface has the advantage of better compile time error checking, since
 262 misspelled names of colors or attributes in calls to color() and colored()
 263 won't be caught until runtime whereas misspelled names of constants will
 264 be caught at compile time.  So, polute your namespace with almost two
 265 dozen subroutines that you may not even use that often, or risk a silly
 266 bug by mistyping an attribute.  Your choice, TMTOWTDI after all.
 267
 268 =head1 DIAGNOSTICS
 269
 270 =over 4
 271
 272 =item Invalid attribute name %s
 273
 274 (F) You passed an invalid attribute name to either color() or colored().
 275
 276 =item Name "%s" used only once: possible typo
 277
 278 (W) You probably mistyped a constant color name such as:
 279
 280     print FOOBAR "This text is color FOOBAR\n";
 281
 282 It's probably better to always use commas after constant names in order to
 283 force the next error.
 284
 285 =item No comma allowed after filehandle
 286
 287 (F) You probably mistyped a constant color name such as:
 288
 289     print FOOBAR, "This text is color FOOBAR\n";
 290
 291 Generating this fatal compile error is one of the main advantages of using
 292 the constants interface, since you'll immediately know if you mistype a
 293 color name.
 294
 295 =item Bareword "%s" not allowed while "strict subs" in use
 296
 297 (F) You probably mistyped a constant color name such as:
 298
 299     $Foobar = FOOBAR . "This line should be blue\n";
 300
 301 or:
 302
 303     @Foobar = FOOBAR, "This line should be blue\n";
 304
 305 This will only show up under use strict (another good reason to run under
 306 use strict).
 307
 308 =back
 309
 310 =head1 RESTRICTIONS
 311
 312 It would be nice if one could leave off the commas around the constants
 313 entirely and just say:
 314
 315     print BOLD BLUE ON_WHITE "Text\n" RESET;
 316
 317 but the syntax of Perl doesn't allow this.  You need a comma after the
 318 string.  (Of course, you may consider it a bug that commas between all the
 319 constants aren't required, in which case you may feel free to insert
 320 commas unless you're using $Term::ANSIColor::AUTORESET.)
 321
 322 For easier debuging, you may prefer to always use the commas when not
 323 setting $Term::ANSIColor::AUTORESET so that you'll get a fatal compile
 324 error rather than a warning.
 325
 326 =head1 NOTES
 327
 328 Jean Delvare provided the following table of different common terminal
 329 emulators and their support for the various attributes:
 330
 331               clear    bold     dark    under    blink   reverse  conceal
 332  ------------------------------------------------------------------------
 333  xterm         yes      yes      no      yes     bold      yes      yes
 334  linux         yes      yes      yes    bold      yes      yes      no
 335  rxvt          yes      yes      no      yes  bold/black   yes      no
 336  dtterm        yes      yes      yes     yes    reverse    yes      yes
 337  teraterm      yes    reverse    no      yes    rev/red    yes      no
 338  aixterm      kinda   normal     no      yes      no       yes      yes
 339
 340 Where the entry is other than yes or no, that emulator interpret the given
 341 attribute as something else instead.  Note that on an aixterm, clear
 342 doesn't reset colors; you have to explicitly set the colors back to what
 343 you want.  More entries in this table are welcome.
 344
 345 =head1 AUTHORS
 346
 347 Original idea (using constants) by Zenin (zenin@best.com), reimplemented
 348 using subs by Russ Allbery (rra@stanford.edu), and then combined with the
 349 original idea by Russ with input from Zenin.
 350
 351 =cut