mingw/html/lib/Term/ANSIColor.html

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  13 <big><strong><span class="block">&nbsp;Term::ANSIColor - Color screen output using ANSI escape sequences</span></strong></big>
  14 </td></tr>
  15 </table>
  16
  17 <p><a name="__index__"></a></p>
  18 <!-- INDEX BEGIN -->
  19
  20 <ul>
  21
  22         <li><a href="#name">NAME</a></li>
  23         <li><a href="#synopsis">SYNOPSIS</a></li>
  24         <li><a href="#description">DESCRIPTION</a></li>
  25         <li><a href="#diagnostics">DIAGNOSTICS</a></li>
  26         <li><a href="#environment">ENVIRONMENT</a></li>
  27         <li><a href="#restrictions">RESTRICTIONS</a></li>
  28         <li><a href="#notes">NOTES</a></li>
  29         <li><a href="#see_also">SEE ALSO</a></li>
  30         <li><a href="#authors">AUTHORS</a></li>
  31         <li><a href="#copyright_and_license">COPYRIGHT AND LICENSE</a></li>
  32 </ul>
  33 <!-- INDEX END -->
  34
  35 <hr />
  36 <p>
  37 </p>
  38 <h1><a name="name">NAME</a></h1>
  39 <p>Term::ANSIColor - Color screen output using ANSI escape sequences</p>
  40 <p>
  41 </p>
  42 <hr />
  43 <h1><a name="synopsis">SYNOPSIS</a></h1>
  44 <pre>
  45     use Term::ANSIColor;
  46     print color 'bold blue';
  47     print &quot;This text is bold blue.\n&quot;;
  48     print color 'reset';
  49     print &quot;This text is normal.\n&quot;;
  50     print colored (&quot;Yellow on magenta.\n&quot;, 'yellow on_magenta');
  51     print &quot;This text is normal.\n&quot;;
  52     print colored ['yellow on_magenta'], &quot;Yellow on magenta.\n&quot;;</pre>
  53 <pre>
  54     use Term::ANSIColor qw(uncolor);
  55     print uncolor '01;31', &quot;\n&quot;;</pre>
  56 <pre>
  57     use Term::ANSIColor qw(:constants);
  58     print BOLD, BLUE, &quot;This text is in bold blue.\n&quot;, RESET;</pre>
  59 <pre>
  60     use Term::ANSIColor qw(:constants);
  61     $Term::ANSIColor::AUTORESET = 1;
  62     print BOLD BLUE &quot;This text is in bold blue.\n&quot;;
  63     print &quot;This text is normal.\n&quot;;</pre>
  64 <p>
  65 </p>
  66 <hr />
  67 <h1><a name="description">DESCRIPTION</a></h1>
  68 <p>This module has two interfaces, one through <code>color()</code> and <code>colored()</code> and the
  69 other through constants.  It also offers the utility function uncolor(),
  70 which has to be explicitly imported to be used (see <em>SYNOPSIS</em>).</p>
  71 <p><code>color()</code> takes any number of strings as arguments and considers them to be
  72 space-separated lists of attributes.  It then forms and returns the escape
  73 sequence to set those attributes.  It doesn't print it out, just returns it,
  74 so you'll have to print it yourself if you want to (this is so that you can
  75 save it as a string, pass it to something else, send it to a file handle, or
  76 do anything else with it that you might care to).</p>
  77 <p><code>uncolor()</code> performs the opposite translation, turning escape sequences
  78 into a list of strings.</p>
  79 <p>The recognized attributes (all of which should be fairly intuitive) are
  80 clear, reset, dark, bold, underline, underscore, blink, reverse, concealed,
  81 black, red, green, yellow, blue, magenta, on_black, on_red, on_green,
  82 on_yellow, on_blue, on_magenta, on_cyan, and on_white.  Case is not
  83 significant.  Underline and underscore are equivalent, as are clear and
  84 reset, so use whichever is the most intuitive to you.  The color alone sets
  85 the foreground color, and on_color sets the background color.</p>
  86 <p>Note that not all attributes are supported by all terminal types, and some
  87 terminals may not support any of these sequences.  Dark, blink, and
  88 concealed in particular are frequently not implemented.</p>
  89 <p>Attributes, once set, last until they are unset (by sending the attribute
  90 ``reset'').  Be careful to do this, or otherwise your attribute will last
  91 after your script is done running, and people get very annoyed at having
  92 their prompt and typing changed to weird colors.</p>
  93 <p>As an aid to help with this, <code>colored()</code> takes a scalar as the first argument
  94 and any number of attribute strings as the second argument and returns the
  95 scalar wrapped in escape codes so that the attributes will be set as
  96 requested before the string and reset to normal after the string.
  97 Alternately, you can pass a reference to an array as the first argument, and
  98 then the contents of that array will be taken as attributes and color codes
  99 and the remainder of the arguments as text to colorize.</p>
 100 <p>Normally, <code>colored()</code> just puts attribute codes at the beginning and end of
 101 the string, but if you set $Term::ANSIColor::EACHLINE to some string, that
 102 string will be considered the line delimiter and the attribute will be set
 103 at the beginning of each line of the passed string and reset at the end of
 104 each line.  This is often desirable if the output is being sent to a program
 105 like a pager that can be confused by attributes that span lines.  Normally
 106 you'll want to set $Term::ANSIColor::EACHLINE to <code>&quot;\n&quot;</code> to use this
 107 feature.</p>
 108 <p>Alternately, if you import <code>:constants</code>, you can use the constants CLEAR,
 109 RESET, BOLD, DARK, UNDERLINE, UNDERSCORE, BLINK, REVERSE, CONCEALED, BLACK,
 110 RED, GREEN, YELLOW, BLUE, MAGENTA, CYAN, WHITE, ON_BLACK, ON_RED, ON_GREEN,
 111 ON_YELLOW, ON_BLUE, ON_MAGENTA, ON_CYAN, and ON_WHITE directly.  These are
 112 the same as <code>color('attribute')</code> and can be used if you prefer typing:</p>
 113 <pre>
 114     print BOLD BLUE ON_WHITE &quot;Text\n&quot;, RESET;</pre>
 115 <p>to</p>
 116 <pre>
 117     print colored (&quot;Text\n&quot;, 'bold blue on_white');</pre>
 118 <p>When using the constants, if you don't want to have to remember to add the
 119 <code>, RESET</code> at the end of each print line, you can set
 120 $Term::ANSIColor::AUTORESET to a true value.  Then, the display mode will
 121 automatically be reset if there is no comma after the constant.  In other
 122 words, with that variable set:</p>
 123 <pre>
 124     print BOLD BLUE &quot;Text\n&quot;;</pre>
 125 <p>will reset the display mode afterwards, whereas:</p>
 126 <pre>
 127     print BOLD, BLUE, &quot;Text\n&quot;;</pre>
 128 <p>will not.</p>
 129 <p>The subroutine interface has the advantage over the constants interface in
 130 that only two subroutines are exported into your namespace, versus
 131 twenty-two in the constants interface.  On the flip side, the constants
 132 interface has the advantage of better compile time error checking, since
 133 misspelled names of colors or attributes in calls to <code>color()</code> and <code>colored()</code>
 134 won't be caught until runtime whereas misspelled names of constants will be
 135 caught at compile time.  So, polute your namespace with almost two dozen
 136 subroutines that you may not even use that often, or risk a silly bug by
 137 mistyping an attribute.  Your choice, TMTOWTDI after all.</p>
 138 <p>
 139 </p>
 140 <hr />
 141 <h1><a name="diagnostics">DIAGNOSTICS</a></h1>
 142 <dl>
 143 <dt><strong><a name="item_bad_escape_sequence__25s">Bad escape sequence %s</a></strong>
 144
 145 <dd>
 146 <p>(F) You passed an invalid ANSI escape sequence to uncolor().</p>
 147 </dd>
 148 </li>
 149 <dt><strong><a name="item_bareword__22_25s_22_not_allowed_while__22strict_su">Bareword ``%s'' not allowed while ``strict subs'' in use</a></strong>
 150
 151 <dd>
 152 <p>(F) You probably mistyped a constant color name such as:</p>
 153 </dd>
 154 <dd>
 155 <pre>
 156     $Foobar = FOOBAR . &quot;This line should be blue\n&quot;;</pre>
 157 </dd>
 158 <dd>
 159 <p>or:</p>
 160 </dd>
 161 <dd>
 162 <pre>
 163     @Foobar = FOOBAR, &quot;This line should be blue\n&quot;;</pre>
 164 </dd>
 165 <dd>
 166 <p>This will only show up under use strict (another good reason to run under
 167 use strict).</p>
 168 </dd>
 169 </li>
 170 <dt><strong><a name="item_invalid_attribute_name__25s">Invalid attribute name %s</a></strong>
 171
 172 <dd>
 173 <p>(F) You passed an invalid attribute name to either <code>color()</code> or colored().</p>
 174 </dd>
 175 </li>
 176 <dt><strong><a name="item_name__22_25s_22_used_only_once_3a_possible_typo">Name ``%s'' used only once: possible typo</a></strong>
 177
 178 <dd>
 179 <p>(W) You probably mistyped a constant color name such as:</p>
 180 </dd>
 181 <dd>
 182 <pre>
 183     print FOOBAR &quot;This text is color FOOBAR\n&quot;;</pre>
 184 </dd>
 185 <dd>
 186 <p>It's probably better to always use commas after constant names in order to
 187 force the next error.</p>
 188 </dd>
 189 </li>
 190 <dt><strong><a name="item_no_comma_allowed_after_filehandle">No comma allowed after filehandle</a></strong>
 191
 192 <dd>
 193 <p>(F) You probably mistyped a constant color name such as:</p>
 194 </dd>
 195 <dd>
 196 <pre>
 197     print FOOBAR, &quot;This text is color FOOBAR\n&quot;;</pre>
 198 </dd>
 199 <dd>
 200 <p>Generating this fatal compile error is one of the main advantages of using
 201 the constants interface, since you'll immediately know if you mistype a
 202 color name.</p>
 203 </dd>
 204 </li>
 205 <dt><strong><a name="item_no_name_for_escape_sequence__25s">No name for escape sequence %s</a></strong>
 206
 207 <dd>
 208 <p>(F) The ANSI escape sequence passed to <code>uncolor()</code> contains escapes which
 209 aren't recognized and can't be translated to names.</p>
 210 </dd>
 211 </li>
 212 </dl>
 213 <p>
 214 </p>
 215 <hr />
 216 <h1><a name="environment">ENVIRONMENT</a></h1>
 217 <dl>
 218 <dt><strong><a name="item_ansi_colors_disabled">ANSI_COLORS_DISABLED</a></strong>
 219
 220 <dd>
 221 <p>If this environment variable is set, all of the functions defined by this
 222 module (color(), colored(), and all of the constants not previously used in
 223 the program) will not output any escape sequences and instead will just
 224 return the empty string or pass through the original text as appropriate.
 225 This is intended to support easy use of scripts using this module on
 226 platforms that don't support ANSI escape sequences.</p>
 227 </dd>
 228 <dd>
 229 <p>For it to have its proper effect, this environment variable must be set
 230 before any color constants are used in the program.</p>
 231 </dd>
 232 </li>
 233 </dl>
 234 <p>
 235 </p>
 236 <hr />
 237 <h1><a name="restrictions">RESTRICTIONS</a></h1>
 238 <p>It would be nice if one could leave off the commas around the constants
 239 entirely and just say:</p>
 240 <pre>
 241     print BOLD BLUE ON_WHITE &quot;Text\n&quot; RESET;</pre>
 242 <p>but the syntax of Perl doesn't allow this.  You need a comma after the
 243 string.  (Of course, you may consider it a bug that commas between all the
 244 constants aren't required, in which case you may feel free to insert commas
 245 unless you're using $Term::ANSIColor::AUTORESET.)</p>
 246 <p>For easier debuging, you may prefer to always use the commas when not
 247 setting $Term::ANSIColor::AUTORESET so that you'll get a fatal compile error
 248 rather than a warning.</p>
 249 <p>
 250 </p>
 251 <hr />
 252 <h1><a name="notes">NOTES</a></h1>
 253 <p>The codes generated by this module are standard terminal control codes,
 254 complying with ECMA-48 and ISO 6429 (generally referred to as ``ANSI color''
 255 for the color codes).  The non-color control codes (bold, dark, italic,
 256 underline, and reverse) are part of the earlier ANSI X3.64 standard for
 257 control sequences for video terminals and peripherals.</p>
 258 <p>Note that not all displays are ISO 6429-compliant, or even X3.64-compliant
 259 (or are even attempting to be so).  This module will not work as expected on
 260 displays that do not honor these escape sequences, such as cmd.exe, 4nt.exe,
 261 and command.com under either Windows NT or Windows 2000.  They may just be
 262 ignored, or they may display as an ESC character followed by some apparent
 263 garbage.</p>
 264 <p>Jean Delvare provided the following table of different common terminal
 265 emulators and their support for the various attributes and others have helped
 266 me flesh it out:</p>
 267 <pre>
 268               clear    bold     dark    under    blink   reverse  conceal
 269  ------------------------------------------------------------------------
 270  xterm         yes      yes      no      yes     bold      yes      yes
 271  linux         yes      yes      yes    bold      yes      yes      no
 272  rxvt          yes      yes      no      yes  bold/black   yes      no
 273  dtterm        yes      yes      yes     yes    reverse    yes      yes
 274  teraterm      yes    reverse    no      yes    rev/red    yes      no
 275  aixterm      kinda   normal     no      yes      no       yes      yes
 276  PuTTY         yes     color     no      yes      no       yes      no
 277  Windows       yes      no       no      no       no       yes      no
 278  Cygwin SSH    yes      yes      no     color    color    color     yes
 279  Mac Terminal  yes      yes      no      yes      yes      yes      yes</pre>
 280 <p>Windows is Windows telnet, Cygwin SSH is the OpenSSH implementation under
 281 Cygwin on Windows NT, and Mac Terminal is the Terminal application in Mac OS
 282 X.  Where the entry is other than yes or no, that emulator displays the
 283 given attribute as something else instead.  Note that on an aixterm, clear
 284 doesn't reset colors; you have to explicitly set the colors back to what you
 285 want.  More entries in this table are welcome.</p>
 286 <p>Note that codes 3 (italic), 6 (rapid blink), and 9 (strikethrough) are
 287 specified in ANSI X3.64 and ECMA-048 but are not commonly supported by most
 288 displays and emulators and therefore aren't supported by this module at the
 289 present time.  ECMA-048 also specifies a large number of other attributes,
 290 including a sequence of attributes for font changes, Fraktur characters,
 291 double-underlining, framing, circling, and overlining.  As none of these
 292 attributes are widely supported or useful, they also aren't currently
 293 supported by this module.</p>
 294 <p>
 295 </p>
 296 <hr />
 297 <h1><a name="see_also">SEE ALSO</a></h1>
 298 <p>ECMA-048 is available on-line (at least at the time of this writing) at
 299 <a href="http://www.ecma-international.org/publications/standards/ECMA-048.HTM">http://www.ecma-international.org/publications/standards/ECMA-048.HTM</a>.</p>
 300 <p>ISO 6429 is available from ISO for a charge; the author of this module does
 301 not own a copy of it.  Since the source material for ISO 6429 was ECMA-048
 302 and the latter is available for free, there seems little reason to obtain
 303 the ISO standard.</p>
 304 <p>The current version of this module is always available from its web site at
 305 <a href="http://www.eyrie.org/~eagle/software/ansicolor/">http://www.eyrie.org/~eagle/software/ansicolor/</a>.  It is also part of the
 306 Perl core distribution as of 5.6.0.</p>
 307 <p>
 308 </p>
 309 <hr />
 310 <h1><a name="authors">AUTHORS</a></h1>
 311 <p>Original idea (using constants) by Zenin, reimplemented using subs by Russ
 312 Allbery &lt;<a href="mailto:rra@stanford.edu">rra@stanford.edu</a>&gt;, and then combined with the original idea by Russ
 313 with input from Zenin.  Russ Allbery now maintains this module.</p>
 314 <p>
 315 </p>
 316 <hr />
 317 <h1><a name="copyright_and_license">COPYRIGHT AND LICENSE</a></h1>
 318 <p>Copyright 1996, 1997, 1998, 2000, 2001, 2002 Russ Allbery &lt;<a href="mailto:rra@stanford.edu">rra@stanford.edu</a>&gt;
 319 and Zenin.  This program is free software; you may redistribute it and/or
 320 modify it under the same terms as Perl itself.</p>
 321 <table border="0" width="100%" cellspacing="0" cellpadding="3">
 322 <tr><td class="block" style="background-color: #cccccc" valign="middle">
 323 <big><strong><span class="block">&nbsp;Term::ANSIColor - Color screen output using ANSI escape sequences</span></strong></big>
 324 </td></tr>
 325 </table>
 326
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