File: perl.html

package info (click to toggle)
perl-doc-html 5.26.0-4
  • links: PTS, VCS
  • area: main
  • in suites: sid
  • size: 39,400 kB
  • sloc: xml: 36; makefile: 7
file content (612 lines) | stat: -rw-r--r-- 55,455 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
  <title>perl - perldoc.perl.org</title>
  <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
  <meta http-equiv="Content-Language" content="en-gb">
  <link rel="search" type="application/opensearchdescription+xml" title="Search perldoc.perl.org" href="/static/search.xml"/>
  <link href="static/css-20100830.css" rel="stylesheet" rev="stylesheet" type="text/css" media="screen">
  <link href="static/exploreperl.css" rel="stylesheet" rev="stylesheet" type="text/css">
</head>

<body onLoad="perldoc.startup();" onPageShow="if (event.persisted) perldoc.startup();">
    <div id="page">
      
      <div id="header">
	<div id="homepage_link">
	  <a href="index.html"></a>
	</div>
	<div id="strapline">
	  Perl Programming Documentation
	</div>
	<div id="download_link" class="download">
	  <a href="http://www.perl.org/get.html">Download Perl</a>
	</div>
	<div id="explore_link" class="download">
	  <a id="explore_anchor" href="#">Explore</a>
	</div>
      </div>
      
      <div id="body">
        <div id="left_column">
          <div class="side_group">
            
	    <div class="side_panel doc_panel">
              <p>Manual</p>
              <ul>
                <li><a href="index-overview.html">Overview</a>
                <li><a href="index-tutorials.html">Tutorials</a>
                <li><a href="index-faq.html">FAQs</a>
                <li><a href="index-history.html">History / Changes</a>
                <li><a href="index-licence.html">License</a>
              </ul>
            </div>
            <div class="side_panel doc_panel">
              <p>Reference</p>
              <ul>
                <li><a href="index-language.html">Language</a>
                <li><a href="index-functions.html">Functions</a>
                <li><a href="perlop.html">Operators</a>
                <li><a href="perlvar.html">Special Variables</a>
                <li><a href="index-pragmas.html">Pragmas</a>
                <li><a href="index-utilities.html">Utilities</a>
                <li><a href="index-internals.html">Internals</a>
                <li><a href="index-platforms.html">Platform Specific</a>
              </ul>
            </div>
            <div class="side_panel doc_panel">
              <p>Modules</p>
              <ul>
		<li>
		
                
                  
		    
		  
		
                  
		    
		  
		
                  
		    
		  
		
                  
		    
		  
		
                  
		    
		  
		
                  
		    
		  
		
                  
		    
		  
		
                  
		    
		  
		
                  
		    
		  
		
                  
		
                  
		
                  
		    
		  
		
                  
		    
		  
		
                  
		    
		  
		
                  
		    
		  
		
                  
		    
		  
		
                  
		
                  
		
                  
		    
		  
		
                  
		    
		  
		
                  
		    
		  
		
                  
		
                  
		
                  
		    
		  
		
                  
		
                  
		
		
                    <a href="index-modules-A.html">A</a>
                    
                      
                        &bull;
                      
                    
                
                    <a href="index-modules-B.html">B</a>
                    
                      
                        &bull;
                      
                    
                
                    <a href="index-modules-C.html">C</a>
                    
                      
                        &bull;
                      
                    
                
                    <a href="index-modules-D.html">D</a>
                    
                      
                        &bull;
                      
                    
                
                    <a href="index-modules-E.html">E</a>
                    
                      
                        <li>
                      
                    
                
                    <a href="index-modules-F.html">F</a>
                    
                      
                        &bull;
                      
                    
                
                    <a href="index-modules-G.html">G</a>
                    
                      
                        &bull;
                      
                    
                
                    <a href="index-modules-H.html">H</a>
                    
                      
                        &bull;
                      
                    
                
                    <a href="index-modules-I.html">I</a>
                    
                      
                        &bull;
                      
                    
                
                    <a href="index-modules-L.html">L</a>
                    
                      
                        <li>
                      
                    
                
                    <a href="index-modules-M.html">M</a>
                    
                      
                        &bull;
                      
                    
                
                    <a href="index-modules-N.html">N</a>
                    
                      
                        &bull;
                      
                    
                
                    <a href="index-modules-O.html">O</a>
                    
                      
                        &bull;
                      
                    
                
                    <a href="index-modules-P.html">P</a>
                    
                      
                        &bull;
                      
                    
                
                    <a href="index-modules-S.html">S</a>
                    
                      
                        <li>
                      
                    
                
                    <a href="index-modules-T.html">T</a>
                    
                      
                        &bull;
                      
                    
                
                    <a href="index-modules-U.html">U</a>
                    
                      
                        &bull;
                      
                    
                
                    <a href="index-modules-X.html">X</a>
                    
                
              </ul>
            </div>
            
	      <div class="side_panel doc_panel">
		<p>Tools</p>
		<ul>
		  <li><a href="preferences.html">Preferences</a>
		</ul>
	      </div>
            
          </div>
        </div>
        <div id="centre_column">
          <div id="content_header">
            <div id="title_bar">
              <div id="page_name">
                <h1>perl</h1>
              </div>
              <div id="perl_version">
                Perl 5 version 26.0 documentation
              </div>
              <div class="page_links" id="page_links_top">
                <a href="#" onClick="toolbar.goToTop();return false;">Go to top</a>
		
              </div>
	      <div class="page_links" id="page_links_bottom">
		
                  <a href="#" id="page_index_toggle">Show page index</a> &bull;
		
                <a href="#" id="recent_pages_toggle">Show recent pages</a>		
	      </div>
	      <div id="search_form">
		<form action="search.html" method="GET" id="search">
		  <input type="text" name="q" id="search_box" alt="Search">
		</form>
	      </div>
            </div>
            <div id="breadcrumbs">
                
    <a href="index.html">Home</a> &gt;
    
      
        <a href="index-overview.html">Overview</a> &gt;
      
    
    perl
  

            </div>
          </div>
          <div id="content_body">
	    <!--[if lt IE 7]>
 <div class="noscript">
   <p>
     <strong>It looks like you're using Internet Explorer 6. This is a very old
     browser which does not offer full support for modern websites.</strong>
   </p>
   <p>
     Unfortunately this means that this website will not work on
     your computer.
   </p>
   <p>
     Don't miss out though! To view the site (and get a better experience from
     many other websites), simply upgrade to
     <a href="http://www.microsoft.com/windows/Internet-explorer/default.aspx">Internet
Explorer 8</a>
     or download an alternative browser such as
     <a href="http://www.mozilla.com/en-US/firefox/firefox.html">Firefox</a>,
     <a href="http://www.apple.com/safari/download/">Safari</a>, or
     <a href="http://www.google.co.uk/chrome">Google Chrome</a>.
   </p>
   <p>
     All of these browsers are free. If you're using a PC at work, you may
     need to contact your IT administrator.
   </p>
 </div>
<![endif]-->
	    <noscript>
	      <div class="noscript">
	      <p>
                <strong>Please note: Many features of this site require JavaScript. You appear to have JavaScript disabled,
	        or are running a non-JavaScript capable web browser.</strong>
	      </p>
	      <p>
		To get the best experience, please enable JavaScript or download a modern web browser such as <a href="http://www.microsoft.com/windows/Internet-explorer/default.aspx">Internet Explorer 8</a>, <a href="http://www.mozilla.com/en-US/firefox/firefox.html">Firefox</a>, <a href="http://www.apple.com/safari/download/">Safari</a>, or <a href="http://www.google.co.uk/chrome">Google Chrome</a>.
              </p>
	      </div>
	    </noscript>

	    <div id="recent_pages" class="hud_container">
	      <div id="recent_pages_header" class="hud_header">
		<div id="recent_pages_close" class="hud_close"><a href="#" onClick="recentPages.hide();return false;"></a></div>
		<div id="recent_pages_title" class="hud_title"><span class="hud_span_top">Recently read</span></div>
		<div id="recent_pages_topright" class="hud_topright"></div>
	      </div>
	      <div id="recent_pages_content" class="hud_content">
	      </div>
	      <div id="recent_pages_footer" class="hud_footer">
		<div id="recent_pages_bottomleft" class="hud_bottomleft"></div>
		<div id="recent_pages_bottom" class="hud_bottom"><span class="hud_span_bottom"></span></div>
		<div id="recent_pages_resize" class="hud_resize"></div>
	      </div>
	    </div>
  
	    <div id="from_search"></div>
            <h1>perl</h1>


  <!--    -->
<ul><li><a href="#NAME">NAME</a><li><a href="#SYNOPSIS">SYNOPSIS</a><li><a href="#GETTING-HELP">GETTING HELP</a><ul><li><a href="#Overview">Overview</a><li><a href="#Tutorials">Tutorials</a><li><a href="#Reference-Manual">Reference Manual</a><li><a href="#Internals-and-C-Language-Interface">Internals and C Language Interface</a><li><a href="#Miscellaneous">Miscellaneous</a><li><a href="#Language-Specific">Language-Specific</a><li><a href="#Platform-Specific">Platform-Specific</a><li><a href="#Stubs-for-Deleted-Documents">Stubs for Deleted Documents</a></ul><li><a href="#DESCRIPTION">DESCRIPTION</a><li><a href="#AVAILABILITY">AVAILABILITY</a><li><a href="#ENVIRONMENT">ENVIRONMENT</a><li><a href="#AUTHOR">AUTHOR</a><li><a href="#FILES">FILES</a><li><a href="#SEE-ALSO">SEE ALSO</a><li><a href="#DIAGNOSTICS">DIAGNOSTICS</a><li><a href="#BUGS">BUGS</a><li><a href="#NOTES">NOTES</a></ul><a name="NAME"></a><h1>NAME</h1>
<p>perl - The Perl 5 language interpreter</p>
<a name="SYNOPSIS"></a><h1>SYNOPSIS</h1>
<p><b>perl</b>	[ <b>-sTtuUWX</b> ]
	[ <b>-hv</b> ] [ <b>-V</b>[:<i>configvar</i>] ]
	[ <b>-cw</b> ] [ <b>-d</b>[<b>t</b>][:<i>debugger</i>] ] [ <b>-D</b>[<i>number/list</i>] ]
	[ <b>-pna</b> ] [ <b>-F</b><i>pattern</i> ] [ <b>-l</b>[<i>octal</i>] ] [ <b>-0</b>[<i>octal/hexadecimal</i>] ]
	[ <b>-I</b><i>dir</i> ] [ <b>-m</b>[<b>-</b>]<i>module</i> ] [ <b>-M</b>[<b>-</b>]<i>'module...'</i> ] [ <b>-f</b> ]
	[ <b>-C [<i>number/list</i>] </b>]
	[ <b>-S</b> ]
	[ <b>-x</b>[<i>dir</i>] ]
	[ <b>-i</b>[<i>extension</i>] ]
	[ [<b>-e</b>|<b>-E</b>] <i>'command'</i> ] [ <b>--</b> ] [ <i>programfile</i> ] [ <i>argument</i> ]...</p>
<p>For more information on these options, you can run <code class="inline"><span class="w">perldoc</span> <span class="w">perlrun</span></code>
.</p>
<a name="GETTING-HELP"></a><h1>GETTING HELP</h1>
<p>The <i>perldoc</i> program gives you access to all the documentation that comes
with Perl.  You can get more documentation, tutorials and community support
online at <a href="http://www.perl.org/">http://www.perl.org/</a>.</p>
<p>If you're new to Perl, you should start by running <code class="inline"><span class="w">perldoc</span> <span class="w">perlintro</span></code>
,
which is a general intro for beginners and provides some background to help
you navigate the rest of Perl's extensive documentation.  Run <code class="inline"><span class="w">perldoc</span>
<span class="w">perldoc</span></code>
 to learn more things you can do with <i>perldoc</i>.</p>
<p>For ease of access, the Perl manual has been split up into several sections.</p>
<a name="Overview"></a><h2>Overview</h2>
<pre class="verbatim"><ol><li>    <span class="w">perl</span>		<span class="w">Perl</span> <span class="w">overview</span> <span class="s">(</span><span class="w">this</span> <span class="w">section</span><span class="s">)</span></li><li>    <span class="w"><a href="perlintro.html">perlintro</a></span>		<span class="w">Perl</span> <span class="w">introduction</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">beginners</span></li><li>    <span class="w"><a href="perlrun.html">perlrun</a></span>		<span class="w">Perl</span> <span class="w">execution</span> <a class="l_k" href="functions/and.html">and</a> <span class="w">options</span></li><li>    <span class="w">perltoc</span>		<span class="w">Perl</span> <span class="w">documentation</span> <span class="w">table</span> <span class="w">of</span> <span class="w">contents</span></li></ol></pre><a name="Tutorials"></a><h2>Tutorials</h2>
<pre class="verbatim"><ol><li>    <span class="w"><a href="perlreftut.html">perlreftut</a></span>		<span class="w">Perl</span> <span class="w">references</span> <span class="w">short</span> <span class="w">introduction</span></li><li>    <span class="w"><a href="perldsc.html">perldsc</a></span>		<span class="w">Perl</span> <span class="w">data</span> <span class="w">structures</span> <span class="w">intro</span></li><li>    <span class="w"><a href="perllol.html">perllol</a></span>		<span class="w">Perl</span> <span class="w">data</span> <span class="w">structures</span><span class="co">:</span> <span class="w">arrays</span> <span class="w">of</span> <span class="w">arrays</span></li><li></li><li>    <span class="w"><a href="perlrequick.html">perlrequick</a></span> 	<span class="w">Perl</span> <span class="w">regular</span> <span class="w">expressions</span> <span class="w">quick</span> <span class="w">start</span></li><li>    <span class="w"><a href="perlretut.html">perlretut</a></span>		<span class="w">Perl</span> <span class="w">regular</span> <span class="w">expressions</span> <span class="w">tutorial</span></li><li></li><li>    <span class="w"><a href="perlootut.html">perlootut</a></span>		<span class="w">Perl</span> <span class="w">OO</span> <span class="w">tutorial</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">beginners</span></li><li></li><li>    <span class="w"><a href="perlperf.html">perlperf</a></span>		<span class="w">Perl</span> <span class="w">Performance</span> <a class="l_k" href="functions/and.html">and</a> <span class="w">Optimization</span> <span class="w">Techniques</span></li><li></li><li>    <span class="w"><a href="perlstyle.html">perlstyle</a></span>		<span class="w">Perl</span> <span class="w">style</span> <span class="w">guide</span></li><li></li><li>    <span class="w"><a href="perlcheat.html">perlcheat</a></span>		<span class="w">Perl</span> <span class="w">cheat</span> <span class="w">sheet</span></li><li>    <span class="w"><a href="perltrap.html">perltrap</a></span>		<span class="w">Perl</span> <span class="w">traps</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">the</span> <span class="w">unwary</span></li><li>    <span class="w"><a href="perldebtut.html">perldebtut</a></span>		<span class="w">Perl</span> <span class="w">debugging</span> <span class="w">tutorial</span></li><li></li><li>    <span class="w"><a href="perlfaq.html">perlfaq</a></span>		<span class="w">Perl</span> <span class="w">frequently</span> <span class="w">asked</span> <span class="w">questions</span></li><li>      <span class="w"><a href="perlfaq1.html">perlfaq1</a></span>		<span class="w">General</span> <span class="w">Questions</span> <span class="w">About</span> <span class="w">Perl</span></li><li>      <span class="w"><a href="perlfaq2.html">perlfaq2</a></span>		<span class="w">Obtaining</span> <a class="l_k" href="functions/and.html">and</a> <span class="w">Learning</span> <span class="w">about</span> <span class="w">Perl</span></li><li>      <span class="w"><a href="perlfaq3.html">perlfaq3</a></span>		<span class="w">Programming</span> <span class="w">Tools</span></li><li>      <span class="w"><a href="perlfaq4.html">perlfaq4</a></span>		<span class="w">Data</span> <span class="w">Manipulation</span></li><li>      <span class="w"><a href="perlfaq5.html">perlfaq5</a></span>		<span class="w">Files</span> <a class="l_k" href="functions/and.html">and</a> <span class="w">Formats</span></li><li>      <span class="w"><a href="perlfaq6.html">perlfaq6</a></span>		<span class="w">Regexes</span></li><li>      <span class="w"><a href="perlfaq7.html">perlfaq7</a></span>		<span class="w">Perl</span> <span class="w">Language</span> <span class="w">Issues</span></li><li>      <span class="w"><a href="perlfaq8.html">perlfaq8</a></span>		<span class="w">System</span> <span class="w">Interaction</span></li><li>      <span class="w"><a href="perlfaq9.html">perlfaq9</a></span>		<span class="w">Networking</span></li></ol></pre><a name="Reference-Manual"></a><h2>Reference Manual</h2>
<pre class="verbatim"><ol><li>    <span class="w"><a href="perlsyn.html">perlsyn</a></span>		<span class="w">Perl</span> <span class="w">syntax</span></li><li>    <span class="w"><a href="perldata.html">perldata</a></span>		<span class="w">Perl</span> <span class="w">data</span> <span class="w">structures</span></li><li>    <span class="w"><a href="perlop.html">perlop</a></span>		<span class="w">Perl</span> <span class="w">operators</span> <a class="l_k" href="functions/and.html">and</a> <span class="w">precedence</span></li><li>    <span class="w"><a href="perlsub.html">perlsub</a></span>		<span class="w">Perl</span> <span class="w">subroutines</span></li><li>    <span class="w"><a href="perlfunc.html">perlfunc</a></span>		<span class="w">Perl</span> <span class="w">built</span>-<span class="w">in</span> <span class="w">functions</span></li><li>      <span class="w"><a href="perlopentut.html">perlopentut</a></span>	<span class="w">Perl</span> <a class="l_k" href="functions/open.html">open</a><span class="s">(</span><span class="s">)</span> <span class="w">tutorial</span></li><li>      <span class="w"><a href="perlpacktut.html">perlpacktut</a></span>	<span class="w">Perl</span> <a class="l_k" href="functions/pack.html">pack</a><span class="s">(</span><span class="s">)</span> <a class="l_k" href="functions/and.html">and</a> <a class="l_k" href="functions/unpack.html">unpack</a><span class="s">(</span><span class="s">)</span> <span class="w">tutorial</span></li><li>    <span class="w"><a href="perlpod.html">perlpod</a></span>		<span class="w">Perl</span> <span class="w">plain</span> <span class="w">old</span> <span class="w">documentation</span></li><li>    <span class="w"><a href="perlpodspec.html">perlpodspec</a></span> 	<span class="w">Perl</span> <span class="w">plain</span> <span class="w">old</span> <span class="w">documentation</span> format specification</li><li><span class="hh">    <a href="perlpodstyle.html">perlpodstyle</a>	Perl POD style guide</span></li><li><span class="hh">    <a href="perldiag.html">perldiag</a>		Perl diagnostic messages</span></li><li><span class="hh">    <a href="perldeprecation.html">perldeprecation</a>     Perl deprecations</span></li><li><span class="hh">    <a href="perllexwarn.html">perllexwarn</a> 	Perl warnings and their control</span></li><li><span class="hh">    <a href="perldebug.html">perldebug</a>		Perl debugging</span></li><li><span class="hh">    <a href="perlvar.html">perlvar</a>		Perl predefined variables</span></li><li><span class="hh">    <a href="perlre.html">perlre</a>		Perl regular expressions, the rest of the story</span></li><li><span class="hh">    <a href="perlrebackslash.html">perlrebackslash</a>	Perl regular expression backslash sequences</span></li><li><span class="hh">    <a href="perlrecharclass.html">perlrecharclass</a>	Perl regular expression character classes</span></li><li><span class="hh">    <a href="perlreref.html">perlreref</a>		Perl regular expressions quick reference</span></li><li><span class="hh">    <a href="perlref.html">perlref</a>		Perl references, the rest of the story</span></li><li><span class="hh">    <a href="perlform.html">perlform</a>		Perl formats</span></li><li><span class="hh">    <a href="perlobj.html">perlobj</a>		Perl objects</span></li><li><span class="hh">    <a href="perltie.html">perltie</a>		Perl objects hidden behind simple variables</span></li><li><span class="hh">      <a href="perldbmfilter.html">perldbmfilter</a>	Perl DBM filters</span></li><li></li><li><span class="hh">    <a href="perlipc.html">perlipc</a>		Perl interprocess communication</span></li><li><span class="hh">    <a href="perlfork.html">perlfork</a>		Perl fork() information</span></li><li><span class="hh">    <a href="perlnumber.html">perlnumber</a>		Perl number semantics</span></li><li></li><li><span class="hh">    <a href="perlthrtut.html">perlthrtut</a>		Perl threads tutorial</span></li><li></li><li><span class="hh">    <a href="perlport.html">perlport</a>		Perl portability guide</span></li><li><span class="hh">    <a href="perllocale.html">perllocale</a>		Perl locale support</span></li><li><span class="hh">    <a href="perluniintro.html">perluniintro</a>	Perl Unicode introduction</span></li><li><span class="hh">    <a href="perlunicode.html">perlunicode</a> 	Perl Unicode support</span></li><li><span class="hh">    <a href="perlunicook.html">perlunicook</a> 	Perl Unicode cookbook</span></li><li><span class="hh">    <a href="perlunifaq.html">perlunifaq</a>		Perl Unicode FAQ</span></li><li><span class="hh">    <a href="perluniprops.html">perluniprops</a>	Index of Unicode properties in Perl</span></li><li><span class="hh">    <a href="perlunitut.html">perlunitut</a>		Perl Unicode tutorial</span></li><li><span class="hh">    <a href="perlebcdic.html">perlebcdic</a>		Considerations for running Perl on EBCDIC platforms</span></li><li></li><li><span class="hh">    <a href="perlsec.html">perlsec</a>		Perl security</span></li><li></li><li><span class="hh">    <a href="perlmod.html">perlmod</a>		Perl modules: how they work</span></li><li><span class="hh">    <a href="perlmodlib.html">perlmodlib</a>		Perl modules: how to write and use</span></li><li><span class="hh">    <a href="perlmodstyle.html">perlmodstyle</a>	Perl modules: how to write modules with style</span></li><li><span class="hh">    <a href="perlmodinstall.html">perlmodinstall</a>	Perl modules: how to install from CPAN</span></li><li><span class="hh">    <a href="perlnewmod.html">perlnewmod</a>		Perl modules: preparing a new module for distribution</span></li><li><span class="hh">    <a href="perlpragma.html">perlpragma</a>		Perl modules: writing a user pragma</span></li><li></li><li><span class="hh">    <a href="perlutil.html">perlutil</a>		utilities packaged with the Perl distribution</span></li><li></li><li><span class="hh">    <a href="perlfilter.html">perlfilter</a>		Perl source filters</span></li><li></li><li><span class="hh">    <a href="perldtrace.html">perldtrace</a>		Perl&#39;s support for DTrace</span></li><li></li><li><span class="hh">    <a href="perlglossary.html">perlglossary</a>	Perl Glossary</span></li></ol></pre><a name="Internals-and-C-Language-Interface"></a><h2>Internals and C Language Interface</h2>
<pre class="verbatim"><ol><li>    <span class="w"><a href="perlembed.html">perlembed</a></span>		<span class="w">Perl</span> <span class="w">ways</span> <span class="w">to</span> <span class="w">embed</span> <span class="w">perl</span> <span class="w">in</span> <span class="w">your</span> <span class="w">C</span> <a class="l_k" href="functions/or.html">or</a> <span class="w">C</span>++ <span class="w">application</span></li><li>    <span class="w"><a href="perldebguts.html">perldebguts</a></span> 	<span class="w">Perl</span> <span class="w">debugging</span> <span class="w">guts</span> <a class="l_k" href="functions/and.html">and</a> <span class="w">tips</span></li><li>    <span class="w"><a href="perlxstut.html">perlxstut</a></span>		<span class="w">Perl</span> <span class="w">XS</span> <span class="w">tutorial</span></li><li>    <span class="w"><a href="perlxs.html">perlxs</a></span>		<span class="w">Perl</span> <span class="w">XS</span> <span class="w">application</span> <span class="w">programming</span> <span class="w">interface</span></li><li>    <span class="w"><a href="perlxstypemap.html">perlxstypemap</a></span>	<span class="w">Perl</span> <span class="w">XS</span> <span class="w">C</span>/<span class="w">Perl</span> <span class="w">type</span> <span class="w">conversion</span> <span class="w">tools</span></li><li>    <span class="w"><a href="perlclib.html">perlclib</a></span>		<span class="w">Internal</span> <span class="w">replacements</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">standard</span> <span class="w">C</span> <span class="w">library</span> <span class="w">functions</span></li><li>    <span class="w"><a href="perlguts.html">perlguts</a></span>		<span class="w">Perl</span> <span class="w">internal</span> <span class="w">functions</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">those</span> <span class="w">doing</span> <span class="w">extensions</span></li><li>    <span class="w"><a href="perlcall.html">perlcall</a></span>		<span class="w">Perl</span> <span class="w">calling</span> <span class="w">conventions</span> <span class="w">from</span> <span class="w">C</span></li><li>    <span class="w"><a href="perlmroapi.html">perlmroapi</a></span>		<span class="w">Perl</span> <span class="w">method</span> <span class="w">resolution</span> <span class="w">plugin</span> <span class="w">interface</span></li><li>    <span class="w"><a href="perlreapi.html">perlreapi</a></span>		<span class="w">Perl</span> <span class="w">regular</span> <span class="w">expression</span> <span class="w">plugin</span> <span class="w">interface</span></li><li>    <span class="w"><a href="perlreguts.html">perlreguts</a></span>		<span class="w">Perl</span> <span class="w">regular</span> <span class="w">expression</span> <span class="w">engine</span> <span class="w">internals</span></li><li></li><li>    <span class="w"><a href="perlapi.html">perlapi</a></span>		<span class="w">Perl</span> <span class="w">API</span> <span class="w">listing</span> <span class="s">(</span><span class="w">autogenerated</span><span class="s">)</span></li><li>    <span class="w"><a href="perlintern.html">perlintern</a></span>		<span class="w">Perl</span> <span class="w">internal</span> <span class="w">functions</span> <span class="s">(</span><span class="w">autogenerated</span><span class="s">)</span></li><li>    <span class="w"><a href="perliol.html">perliol</a></span>		<span class="w">C</span> <span class="w">API</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">Perl&#39;s</span> <span class="w">implementation</span> <span class="w">of</span> <span class="w">IO</span> <span class="w">in</span> <span class="w">Layers</span></li><li>    <span class="w"><a href="perlapio.html">perlapio</a></span>		<span class="w">Perl</span> <span class="w">internal</span> <span class="w">IO</span> <span class="w">abstraction</span> <span class="w">interface</span></li><li></li><li>    <span class="w"><a href="perlhack.html">perlhack</a></span>		<span class="w">Perl</span> <span class="w">hackers</span> <span class="w">guide</span></li><li>    <span class="w"><a href="perlsource.html">perlsource</a></span>		<span class="w">Guide</span> <span class="w">to</span> <span class="w">the</span> <span class="w">Perl</span> <span class="w">source</span> <span class="w">tree</span></li><li>    <span class="w"><a href="perlinterp.html">perlinterp</a></span>		<span class="w">Overview</span> <span class="w">of</span> <span class="w">the</span> <span class="w">Perl</span> <span class="w">interpreter</span> <span class="w">source</span> <a class="l_k" href="functions/and.html">and</a> <span class="w">how</span> <span class="w">it</span> <span class="w">works</span></li><li>    <span class="w"><a href="perlhacktut.html">perlhacktut</a></span> 	<span class="w">Walk</span> <span class="w">through</span> <span class="w">the</span> <span class="w">creation</span> <span class="w">of</span> <span class="w">a</span> <span class="w">simple</span> <span class="w">C</span> <span class="w">code</span> <span class="w">patch</span></li><li>    <span class="w"><a href="perlhacktips.html">perlhacktips</a></span>	<span class="w">Tips</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">Perl</span> <span class="w">core</span> <span class="w">C</span> <span class="w">code</span> <span class="w">hacking</span></li><li>    <span class="w"><a href="perlpolicy.html">perlpolicy</a></span>		<span class="w">Perl</span> <span class="w">development</span> <span class="w">policies</span></li><li>    <span class="w"><a href="perlgit.html">perlgit</a></span>		<span class="w">Using</span> <span class="w">git</span> <span class="w">with</span> <span class="w">the</span> <span class="w">Perl</span> <span class="w">repository</span></li></ol></pre><a name="Miscellaneous"></a><h2>Miscellaneous</h2>
<pre class="verbatim"><ol><li>    <span class="w"><a href="perlbook.html">perlbook</a></span>		<span class="w">Perl</span> <span class="w">book</span> <span class="w">information</span></li><li>    <span class="w"><a href="perlcommunity.html">perlcommunity</a></span>	<span class="w">Perl</span> <span class="w">community</span> <span class="w">information</span></li><li></li><li>    <span class="w"><a href="perldoc.html">perldoc</a></span>		<span class="w">Look</span> <span class="w">up</span> <span class="w">Perl</span> <span class="w">documentation</span> <span class="w">in</span> <span class="w">Pod</span> <a class="l_k" href="functions/format.html">format</a></li><li></li><li><span class="hh">    <a href="perlhist.html">perlhist</a>		Perl history records</span></li><li><span class="hh">    <a href="perldelta.html">perldelta</a>		Perl changes since previous version</span></li><li><span class="hh">    <a href="perl5241delta.html">perl5241delta</a>	Perl changes in version 5.24.1</span></li><li><span class="hh">    <a href="perl5240delta.html">perl5240delta</a>	Perl changes in version 5.24.0</span></li><li><span class="hh">    <a href="perl5223delta.html">perl5223delta</a>	Perl changes in version 5.22.3</span></li><li><span class="hh">    <a href="perl5222delta.html">perl5222delta</a>	Perl changes in version 5.22.2</span></li><li><span class="hh">    <a href="perl5221delta.html">perl5221delta</a>	Perl changes in version 5.22.1</span></li><li><span class="hh">    <a href="perl5220delta.html">perl5220delta</a>	Perl changes in version 5.22.0</span></li><li><span class="hh">    <a href="perl5203delta.html">perl5203delta</a>	Perl changes in version 5.20.3</span></li><li><span class="hh">    <a href="perl5202delta.html">perl5202delta</a>	Perl changes in version 5.20.2</span></li><li><span class="hh">    <a href="perl5201delta.html">perl5201delta</a>	Perl changes in version 5.20.1</span></li><li><span class="hh">    <a href="perl5200delta.html">perl5200delta</a>	Perl changes in version 5.20.0</span></li><li><span class="hh">    <a href="perl5184delta.html">perl5184delta</a>	Perl changes in version 5.18.4</span></li><li><span class="hh">    <a href="perl5182delta.html">perl5182delta</a>	Perl changes in version 5.18.2</span></li><li><span class="hh">    <a href="perl5181delta.html">perl5181delta</a>	Perl changes in version 5.18.1</span></li><li><span class="hh">    <a href="perl5180delta.html">perl5180delta</a>	Perl changes in version 5.18.0</span></li><li><span class="hh">    <a href="perl5163delta.html">perl5163delta</a>	Perl changes in version 5.16.3</span></li><li><span class="hh">    <a href="perl5162delta.html">perl5162delta</a>	Perl changes in version 5.16.2</span></li><li><span class="hh">    <a href="perl5161delta.html">perl5161delta</a>	Perl changes in version 5.16.1</span></li><li><span class="hh">    <a href="perl5160delta.html">perl5160delta</a>	Perl changes in version 5.16.0</span></li><li><span class="hh">    <a href="perl5144delta.html">perl5144delta</a>	Perl changes in version 5.14.4</span></li><li><span class="hh">    <a href="perl5143delta.html">perl5143delta</a>	Perl changes in version 5.14.3</span></li><li><span class="hh">    <a href="perl5142delta.html">perl5142delta</a>	Perl changes in version 5.14.2</span></li><li><span class="hh">    <a href="perl5141delta.html">perl5141delta</a>	Perl changes in version 5.14.1</span></li><li><span class="hh">    <a href="perl5140delta.html">perl5140delta</a>	Perl changes in version 5.14.0</span></li><li><span class="hh">    <a href="perl5125delta.html">perl5125delta</a>	Perl changes in version 5.12.5</span></li><li><span class="hh">    <a href="perl5124delta.html">perl5124delta</a>	Perl changes in version 5.12.4</span></li><li><span class="hh">    <a href="perl5123delta.html">perl5123delta</a>	Perl changes in version 5.12.3</span></li><li><span class="hh">    <a href="perl5122delta.html">perl5122delta</a>	Perl changes in version 5.12.2</span></li><li><span class="hh">    <a href="perl5121delta.html">perl5121delta</a>	Perl changes in version 5.12.1</span></li><li><span class="hh">    <a href="perl5120delta.html">perl5120delta</a>	Perl changes in version 5.12.0</span></li><li><span class="hh">    <a href="perl5101delta.html">perl5101delta</a>	Perl changes in version 5.10.1</span></li><li><span class="hh">    <a href="perl5100delta.html">perl5100delta</a>	Perl changes in version 5.10.0</span></li><li><span class="hh">    <a href="perl589delta.html">perl589delta</a>	Perl changes in version 5.8.9</span></li><li><span class="hh">    <a href="perl588delta.html">perl588delta</a>	Perl changes in version 5.8.8</span></li><li><span class="hh">    <a href="perl587delta.html">perl587delta</a>	Perl changes in version 5.8.7</span></li><li><span class="hh">    <a href="perl586delta.html">perl586delta</a>	Perl changes in version 5.8.6</span></li><li><span class="hh">    <a href="perl585delta.html">perl585delta</a>	Perl changes in version 5.8.5</span></li><li><span class="hh">    <a href="perl584delta.html">perl584delta</a>	Perl changes in version 5.8.4</span></li><li><span class="hh">    <a href="perl583delta.html">perl583delta</a>	Perl changes in version 5.8.3</span></li><li><span class="hh">    <a href="perl582delta.html">perl582delta</a>	Perl changes in version 5.8.2</span></li><li><span class="hh">    <a href="perl581delta.html">perl581delta</a>	Perl changes in version 5.8.1</span></li><li><span class="hh">    <a href="perl58delta.html">perl58delta</a> 	Perl changes in version 5.8.0</span></li><li><span class="hh">    <a href="perl561delta.html">perl561delta</a>	Perl changes in version 5.6.1</span></li><li><span class="hh">    <a href="perl56delta.html">perl56delta</a> 	Perl changes in version 5.6</span></li><li><span class="hh">    <a href="perl5005delta.html">perl5005delta</a>	Perl changes in version 5.005</span></li><li><span class="hh">    <a href="perl5004delta.html">perl5004delta</a>	Perl changes in version 5.004</span></li><li></li><li><span class="hh">    <a href="perlexperiment.html">perlexperiment</a>	A listing of experimental features in Perl</span></li><li></li><li><span class="hh">    <a href="perlartistic.html">perlartistic</a>	Perl Artistic License</span></li><li><span class="hh">    <a href="perlgpl.html">perlgpl</a>		GNU General Public License</span></li></ol></pre><a name="Language-Specific"></a><h2>Language-Specific</h2>
<pre class="verbatim"><ol><li>    perlcn		Perl for Simplified Chinese (in EUC-CN)</li><li>    perljp		Perl for Japanese (in EUC-JP)</li><li>    perlko		Perl for Korean (in EUC-KR)</li><li>    perltw		Perl for Traditional Chinese (in Big5)</li></ol></pre><a name="Platform-Specific"></a><h2>Platform-Specific</h2>
<pre class="verbatim"><ol><li>    <span class="w"><a href="perlaix.html">perlaix</a></span>		<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">AIX</span></li><li>    <span class="w"><a href="perlamiga.html">perlamiga</a></span>		<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">AmigaOS</span></li><li>    <span class="w"><a href="perlandroid.html">perlandroid</a></span>		<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">Android</span></li><li>    <span class="w"><a href="perlbs2000.html">perlbs2000</a></span>		<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">POSIX</span>-<span class="w">BC</span> <span class="w">BS2000</span></li><li>    <span class="w"><a href="perlce.html">perlce</a></span>		<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">WinCE</span></li><li>    <span class="w"><a href="perlcygwin.html">perlcygwin</a></span>		<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">Cygwin</span></li><li>    <span class="w"><a href="perldos.html">perldos</a></span>		<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">DOS</span></li><li>    <span class="w"><a href="perlfreebsd.html">perlfreebsd</a></span> 	<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">FreeBSD</span></li><li>    <span class="w"><a href="perlhaiku.html">perlhaiku</a></span>		<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">Haiku</span></li><li>    <span class="w"><a href="perlhpux.html">perlhpux</a></span>		<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">HP</span>-<span class="w">UX</span></li><li>    <span class="w"><a href="perlhurd.html">perlhurd</a></span>		<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">Hurd</span></li><li>    <span class="w"><a href="perlirix.html">perlirix</a></span>		<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">Irix</span></li><li>    <span class="w"><a href="perllinux.html">perllinux</a></span>		<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">Linux</span></li><li>    <span class="w"><a href="perlmacos.html">perlmacos</a></span>		<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">Mac</span> <span class="w">OS</span> <span class="s">(</span><span class="w">Classic</span><span class="s">)</span></li><li>    <span class="w"><a href="perlmacosx.html">perlmacosx</a></span>		<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">Mac</span> <span class="w">OS</span> <span class="w">X</span></li><li>    <span class="w"><a href="perlnetware.html">perlnetware</a></span> 	<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">NetWare</span></li><li>    <span class="w"><a href="perlopenbsd.html">perlopenbsd</a></span> 	<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">OpenBSD</span></li><li>    <span class="w"><a href="perlos2.html">perlos2</a></span>		<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">OS</span>/<span class="n">2</span></li><li>    <span class="w"><a href="perlos390.html">perlos390</a></span>		<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">OS</span>/<span class="n">390</span></li><li>    <span class="w"><a href="perlos400.html">perlos400</a></span>		<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">OS</span>/<span class="n">400</span></li><li>    <span class="w"><a href="perlplan9.html">perlplan9</a></span>		<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">Plan</span> <span class="n">9</span></li><li>    <span class="w"><a href="perlqnx.html">perlqnx</a></span>		<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">QNX</span></li><li>    <span class="w"><a href="perlriscos.html">perlriscos</a></span>		<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">RISC</span> <span class="w">OS</span></li><li>    <span class="w"><a href="perlsolaris.html">perlsolaris</a></span> 	<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">Solaris</span></li><li>    <span class="w"><a href="perlsymbian.html">perlsymbian</a></span> 	<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">Symbian</span></li><li>    <span class="w"><a href="perlsynology.html">perlsynology</a></span> 	<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">Synology</span></li><li>    <span class="w"><a href="perltru64.html">perltru64</a></span>		<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">Tru64</span></li><li>    <span class="w"><a href="perlvms.html">perlvms</a></span>		<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">VMS</span></li><li>    <span class="w"><a href="perlvos.html">perlvos</a></span>		<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">Stratus</span> <span class="w">VOS</span></li><li>    <span class="w"><a href="perlwin32.html">perlwin32</a></span>		<span class="w">Perl</span> <span class="w">notes</span> <a class="l_k" href="functions/for.html">for</a> <span class="w">Windows</span></li></ol></pre><a name="Stubs-for-Deleted-Documents"></a><h2>Stubs for Deleted Documents</h2>
<pre class="verbatim"><ol><li>    <span class="w"><a href="perlboot.html">perlboot</a></span>		</li><li>    <span class="w"><a href="perlbot.html">perlbot</a></span>		</li><li>    <span class="w"><a href="perlrepository.html">perlrepository</a></span></li><li>    <span class="w"><a href="perltodo.html">perltodo</a></span></li><li>    <span class="w"><a href="perltooc.html">perltooc</a></span>		</li><li>    <span class="w"><a href="perltoot.html">perltoot</a></span></li></ol></pre><p>On a Unix-like system, these documentation files will usually also be
available as manpages for use with the <i>man</i> program.</p>
<p>Some documentation is not available as man pages, so if a
cross-reference is not found by man, try it with <a href="perldoc.html">perldoc</a>.  Perldoc can
also take you directly to documentation for functions (with the <b>-f</b>
switch). See <code class="inline"><span class="w">perldoc</span> --<span class="w">help</span></code>
 (or <code class="inline"><span class="w">perldoc</span> <span class="w">perldoc</span></code>
 or <code class="inline"><span class="w">man</span> <span class="w">perldoc</span></code>
)
for other helpful options <a href="perldoc.html">perldoc</a> has to offer.</p>
<p>In general, if something strange has gone wrong with your program and you're
not sure where you should look for help, try making your code comply with
<b>use strict</b> and <b>use warnings</b>.  These will often point out exactly
where the trouble is.</p>
<a name="DESCRIPTION"></a><h1>DESCRIPTION</h1>
<p>Perl officially stands for Practical Extraction and Report Language,
except when it doesn't.</p>
<p>Perl was originally a language optimized for scanning arbitrary
text files, extracting information from those text files, and printing
reports based on that information.  It quickly became a good language
for many system management tasks. Over the years, Perl has grown into
a general-purpose programming language. It's widely used for everything
from quick "one-liners" to full-scale application development.</p>
<p>The language is intended to be practical (easy to use, efficient,
complete) rather than beautiful (tiny, elegant, minimal).  It combines
(in the author's opinion, anyway) some of the best features of <b>sed</b>,
<b>awk</b>, and <b>sh</b>, making it familiar and easy to use for Unix users to
whip up quick solutions to annoying problems.  Its general-purpose
programming facilities support procedural, functional, and
object-oriented programming paradigms, making Perl a comfortable
language for the long haul on major projects, whatever your bent.</p>
<p>Perl's roots in text processing haven't been forgotten over the years.
It still boasts some of the most powerful regular expressions to be
found anywhere, and its support for Unicode text is world-class.  It
handles all kinds of structured text, too, through an extensive
collection of extensions.  Those libraries, collected in the CPAN,
provide ready-made solutions to an astounding array of problems.  When
they haven't set the standard themselves, they steal from the best
-- just like Perl itself.</p>
<a name="AVAILABILITY"></a><h1>AVAILABILITY</h1>
<p>Perl is available for most operating systems, including virtually
all Unix-like platforms.  See <a href="perlport.html#Supported-Platforms">Supported Platforms in perlport</a>
for a listing.</p>
<a name="ENVIRONMENT"></a><h1>ENVIRONMENT</h1>
<p>See <a href="perlrun.html">perlrun</a>.</p>
<a name="AUTHOR"></a><h1>AUTHOR</h1>
<p>Larry Wall &lt;larry@wall.org&gt;, with the help of oodles of other folks.</p>
<p>If your Perl success stories and testimonials may be of help to others 
who wish to advocate the use of Perl in their applications, 
or if you wish to simply express your gratitude to Larry and the 
Perl developers, please write to perl-thanks@perl.org .</p>
<a name="FILES"></a><h1>FILES</h1>
<pre class="verbatim"><ol><li> "@INC"			locations of perl libraries</li></ol></pre><p>"@INC" above is a reference to the built-in variable of the same name;
see <a href="perlvar.html">perlvar</a> for more information.</p>
<a name="SEE-ALSO"></a><h1>SEE ALSO</h1>
<pre class="verbatim"><ol><li> http://www.perl.org/       the Perl homepage</li><li> http://www.perl.com/       Perl articles (O'Reilly)</li><li> http://www.cpan.org/       the Comprehensive Perl Archive</li><li> http://www.pm.org/         the Perl Mongers</li></ol></pre><a name="DIAGNOSTICS"></a><h1>DIAGNOSTICS</h1>
<p>Using the <code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="w">strict</span></code>
 pragma ensures that all variables are properly
declared and prevents other misuses of legacy Perl features.</p>
<p>The <code class="inline"><a class="l_k" href="functions/use.html">use</a> <span class="w">warnings</span></code>
 pragma produces some lovely diagnostics. One can
also use the <b>-w</b> flag, but its use is normally discouraged, because
it gets applied to all executed Perl code, including that not under
your control.</p>
<p>See <a href="perldiag.html">perldiag</a> for explanations of all Perl's diagnostics.  The <code class="inline"><a class="l_k" href="functions/use.html">use</a>
<span class="w">diagnostics</span></code>
 pragma automatically turns Perl's normally terse warnings
and errors into these longer forms.</p>
<p>Compilation errors will tell you the line number of the error, with an
indication of the next token or token type that was to be examined.
(In a script passed to Perl via <b>-e</b> switches, each
<b>-e</b> is counted as one line.)</p>
<p>Setuid scripts have additional constraints that can produce error
messages such as "Insecure dependency".  See <a href="perlsec.html">perlsec</a>.</p>
<p>Did we mention that you should definitely consider using the <b>use warnings</b>
pragma?</p>
<a name="BUGS"></a><h1>BUGS</h1>
<p>The behavior implied by the <b>use warnings</b> pragma is not mandatory.</p>
<p>Perl is at the mercy of your machine's definitions of various
operations such as type casting, atof(), and floating-point
output with sprintf().</p>
<p>If your stdio requires a seek or eof between reads and writes on a
particular stream, so does Perl.  (This doesn't apply to sysread()
and syswrite().)</p>
<p>While none of the built-in data types have any arbitrary size limits
(apart from memory size), there are still a few arbitrary limits:  a
given variable name may not be longer than 251 characters.  Line numbers
displayed by diagnostics are internally stored as short integers,
so they are limited to a maximum of 65535 (higher numbers usually being
affected by wraparound).</p>
<p>You may mail your bug reports (be sure to include full configuration
information as output by the myconfig program in the perl source
tree, or by <code class="inline"><span class="w">perl</span> -<span class="w">V</span></code>
) to perlbug@perl.org .  If you've succeeded
in compiling perl, the <a href="perlbug.html">perlbug</a> script in the <i>utils/</i> subdirectory
can be used to help mail in a bug report.</p>
<p>Perl actually stands for Pathologically Eclectic Rubbish Lister, but
don't tell anyone I said that.</p>
<a name="NOTES"></a><h1>NOTES</h1>
<p>The Perl motto is "There's more than one way to do it."  Divining
how many more is left as an exercise to the reader.</p>
<p>The three principal virtues of a programmer are Laziness,
Impatience, and Hubris.  See the Camel Book for why.</p>




  <div id="page_index" class="hud_container">
    <div id="page_index_header" class="hud_header">
      <div id="page_index_close" class="hud_close"><a href="#" onClick="pageIndex.hide();return false;"></a></div>
      <div id="page_index_title" class="hud_title"><span class="hud_span_top">Page index</span></div>
      <div id="page_index_topright" class="hud_topright"></div>
    </div>
    <div id="page_index_content" class="hud_content">
      <ul><li><a href="#NAME">NAME</a><li><a href="#SYNOPSIS">SYNOPSIS</a><li><a href="#GETTING-HELP">GETTING HELP</a><ul><li><a href="#Overview">Overview</a><li><a href="#Tutorials">Tutorials</a><li><a href="#Reference-Manual">Reference Manual</a><li><a href="#Internals-and-C-Language-Interface">Internals and C Language Interface</a><li><a href="#Miscellaneous">Miscellaneous</a><li><a href="#Language-Specific">Language-Specific</a><li><a href="#Platform-Specific">Platform-Specific</a><li><a href="#Stubs-for-Deleted-Documents">Stubs for Deleted Documents</a></ul><li><a href="#DESCRIPTION">DESCRIPTION</a><li><a href="#AVAILABILITY">AVAILABILITY</a><li><a href="#ENVIRONMENT">ENVIRONMENT</a><li><a href="#AUTHOR">AUTHOR</a><li><a href="#FILES">FILES</a><li><a href="#SEE-ALSO">SEE ALSO</a><li><a href="#DIAGNOSTICS">DIAGNOSTICS</a><li><a href="#BUGS">BUGS</a><li><a href="#NOTES">NOTES</a></ul>
    </div>
    <div id="page_index_footer" class="hud_footer">
      <div id="page_index_bottomleft" class="hud_bottomleft"></div>
      <div id="page_index_bottom" class="hud_bottom"><span class="hud_span_bottom"></span></div>
      <div id="page_index_resize" class="hud_resize"></div>
    </div>
  </div>


	    &nbsp;
          </div>
          <div id="content_footer">
          </div>
        </div>
        <div class="clear"></div>
      </div>
      
    <div id="footer">
      <div id="footer_content">
        <div id="footer_strapline">
          perldoc.perl.org - Official documentation for the Perl programming language
        </div>
        <div id="footer_links">
          <div id="address">
            <p class="name">Contact details</p>
            <p class="address">
	      Site maintained by <a href="mailto:jj@jonallen.info">Jon Allen (JJ)</a><br>
	    </p>
            <p class="contact">
              Documentation maintained by the <a href="http://lists.cpan.org/showlist.cgi?name=perl5-porters">Perl 5 Porters</a>
            </p>
          </div>
          <ul class="f1">
            <li>Manual
              <ul class="f2">
                <li><a href="index-overview.html">Overview</a>
                <li><a href="index-tutorials.html">Tutorials</a>
                <li><a href="index-faq.html">FAQs</a>
                <li><a href="index-history.html">Changes</a>
              </ul>
            <li>Reference
              <ul class="f2">
                <li><a href="index-language.html">Language</a>
                <li><a href="index-functions.html">Functions</a>
                <li><a href="perlop.html">Operators</a>
                <li><a href="perlvar.html">Variables</a>
              </ul>
            <li>Modules
              <ul class="f2">
                <li><a href="index-modules-A.html">Modules</a>
                <li><a href="index-pragmas.html">Pragmas</a>
                <li><a href="index-utilities.html">Utilities</a>
              </ul>
            <li>Misc
              <ul class="f2">
                <li><a href="index-licence.html">License</a>
                <li><a href="index-internals.html">Internals</a>
                <li><a href="index-platforms.html">Platforms</a>
              </ul>          </ul>
          <div class="clear"></div>
        </div>
      </div>
      <div id="footer_end">
      </div>
    </div>
      
    </div>
      <script language="JavaScript" type="text/javascript" src="static/exploreperl.js"></script>
      <script language="JavaScript" src="static/combined-20100403.js" type="text/javascript"></script>
<script language="JavaScript" type="text/javascript">
  perldoc.setPath(0);
  perldoc.pageName    = 'perl';
  perldoc.pageAddress = 'perl.html';
  perldoc.contentPage = 1;
  explorePerl.render();
  explorePerl.addEvents('explore_anchor');
</script>
    
  </body>
</html>