-
Notifications
You must be signed in to change notification settings - Fork 0
/
features.error-handling.html
736 lines (718 loc) · 12.6 KB
/
features.error-handling.html
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
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
<HTML
><HEAD
><TITLE
>Error Handling</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.57"><LINK
REL="HOME"
TITLE="PHP Manual"
HREF="manual.html"><LINK
REL="UP"
TITLE="Features"
HREF="features.html"><LINK
REL="PREVIOUS"
TITLE="Features"
HREF="features.html"><LINK
REL="NEXT"
TITLE="Creating and manipulating images"
HREF="features.images.html"><META
NAME="HTTP_EQUIV"
CONTENT="text/html; charset=ISO-8859-1"></HEAD
><BODY
CLASS="chapter"
BGCOLOR="#FFFFFF"
TEXT="#000000"
LINK="#0000FF"
VLINK="#840084"
ALINK="#0000FF"
><DIV
CLASS="NAVHEADER"
><TABLE
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="3"
ALIGN="center"
>PHP Manual</TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="bottom"
><A
HREF="features.html"
>Prev</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
></TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="features.images.html"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="chapter"
><H1
><A
NAME="features.error-handling"
>Chapter 15. Error Handling</A
></H1
><P
> There are several types of errors and warnings in PHP. They are:
<DIV
CLASS="table"
><A
NAME="AEN3984"
></A
><P
><B
>Table 15-1. PHP error types</B
></P
><TABLE
BORDER="1"
CLASS="CALSTABLE"
><THEAD
><TR
><TH
ALIGN="LEFT"
VALIGN="MIDDLE"
>Value</TH
><TH
ALIGN="LEFT"
VALIGN="MIDDLE"
>Constant</TH
><TH
ALIGN="LEFT"
VALIGN="MIDDLE"
>Description</TH
><TH
ALIGN="LEFT"
VALIGN="MIDDLE"
>Note</TH
></TR
></THEAD
><TBODY
><TR
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>1</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>E_ERROR</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>fatal run-time errors</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
> </TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>2</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>E_WARNING</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>run-time warnings (non fatal errors)</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
> </TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>4</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>E_PARSE</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>compile-time parse errors</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
> </TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>8</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>E_NOTICE </TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
> run-time notices (less serious than warnings)
</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
> </TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>16</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>E_CORE_ERROR</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>fatal errors that occur during PHP's initial startup</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>PHP 4 only</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>32</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>E_CORE_WARNING</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
> warnings (non fatal errors) that occur during PHP's initial
startup
</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>PHP 4 only</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>64</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>E_COMPILE_ERROR</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>fatal compile-time errors</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>PHP 4 only</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>128</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>E_COMPILE_WARNING</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>compile-time warnings (non fatal errors)</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>PHP 4 only</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>256</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>E_USER_ERROR</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>user-generated error message</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>PHP 4 only</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>512</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>E_USER_WARNING</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>user-generated warning message</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>PHP 4 only</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>1024</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>E_USER_NOTICE </TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>user-generated notice message</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>PHP 4 only</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
> </TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>E_ALL</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
>all of the above, as supported</TD
><TD
ALIGN="LEFT"
VALIGN="MIDDLE"
> </TD
></TR
></TBODY
></TABLE
></DIV
>
</P
><P
> The above values (either numerical or symbolic) are used to build
up a bitmask that specifies which errors to report. You can use the
<A
HREF="language.operators.bitwise.html"
>bitwise operators</A
>
to combine these values or mask out certain types of errors. Note
that only '|', '~', '!', and '&' will be understood within
<TT
CLASS="filename"
>php.ini</TT
>, however, and that no bitwise
operators will be understood within <TT
CLASS="filename"
>php3.ini</TT
>.
</P
><P
> In PHP 4, the default <A
HREF="configuration.html#ini.error-reporting"
>error_reporting</A
> setting is
<TT
CLASS="literal"
>E_ALL & ~E_NOTICE</TT
>, meaning to display all errors
and warnings which are not E_NOTICE-level. In PHP 3, the default
setting is <TT
CLASS="literal"
>(E_ERROR | E_WARNING | E_PARSE)</TT
>,
meaning the same thing. Note, however, that since constants are not
supported in PHP 3's <TT
CLASS="filename"
>php3.ini</TT
>, the <A
HREF="configuration.html#ini.error-reporting"
>error_reporting</A
> setting there
must be numeric; hence, it is <TT
CLASS="literal"
>7</TT
>.
</P
><P
> The initial setting can be changed in the ini file with the <A
HREF="configuration.html#ini.error-reporting"
>error_reporting</A
> directive, in
your Apache <TT
CLASS="filename"
>httpd.conf</TT
> file with the
php_error_reporting (php3_error_reporting for PHP 3) directive, and
lastly it may be set at runtime within a script by using the
<A
HREF="function.error-reporting.html"
><B
CLASS="function"
>error_reporting()</B
></A
> function.
</P
><DIV
CLASS="warning"
><P
></P
><TABLE
CLASS="warning"
BORDER="1"
WIDTH="100%"
><TR
><TD
ALIGN="CENTER"
><B
>Warning</B
></TD
></TR
><TR
><TD
ALIGN="LEFT"
><P
> When upgrading code or servers from PHP 3 to PHP 4 you should
check these settings and calls to
<A
HREF="function.error-reporting.html"
><B
CLASS="function"
>error_reporting()</B
></A
> or you might disable
reporting the new error types, especially E_COMPILE_ERROR. This
may lead to empty documents without any feedback of what happened
or where to look for the problem.
</P
></TD
></TR
></TABLE
></DIV
><P
> All <A
HREF="language.expressions.html"
>PHP expressions</A
> can
also be called with the "@" prefix, which turns off error reporting
for that particular expression. If an error occurred during such
an expression and the <A
HREF="configuration.html#ini.track-errors"
>track_errors</A
> feature is enabled,
you can find the error message in the global variable
$php_errormsg.
</P
><DIV
CLASS="warning"
><P
></P
><TABLE
CLASS="warning"
BORDER="1"
WIDTH="100%"
><TR
><TD
ALIGN="CENTER"
><B
>Warning</B
></TD
></TR
><TR
><TD
ALIGN="LEFT"
><P
> Currently the <A
HREF="language.operators.errorcontrol.html"
>@
error-control operator</A
> prefix will even disable error
reporting for critical errors that will terminate script
execution. Among other things, this means that if you use <A
HREF="language.operators.errorcontrol.html"
>@</A
> to suppress
errors from a certain function and either it isn't available or
has been mistyped, the script will die right there with no
indication as to why.
</P
></TD
></TR
></TABLE
></DIV
><P
> Below we can see an example of using the error handling capabilities in
PHP. We define a error handling function which logs the information into
a file (using an XML format), and e-mails the developer in case a critical
error in the logic happens.
<TABLE
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
CLASS="EXAMPLE"
><TR
><TD
><DIV
CLASS="example"
><A
NAME="AEN4080"
></A
><P
><B
>Example 15-1. Using error handling in a script</B
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="programlisting"
> <?php
// we will do our own error handling
error_reporting(0);
// user defined error handling function
function userErrorHandler ($errno, $errmsg, $filename, $linenum, $vars) {
// timestamp for the error entry
$dt = date("Y-m-d H:i:s (T)");
// define an assoc array of error string
// in reality the only entries we should
// consider are 2,8,256,512 and 1024
$errortype = array (
1 => "Error",
2 => "Warning",
4 => "Parsing Error",
8 => "Notice",
16 => "Core Error",
32 => "Core Warning",
64 => "Compile Error",
128 => "Compile Warning",
256 => "User Error",
512 => "User Warning",
1024=> "User Notice"
);
// set of errors for which a var trace will be saved
$user_errors = array(E_USER_ERROR, E_USER_WARNING, E_USER_NOTICE);
$err = "<errorentry>\n";
$err .= "\t<datetime>".$dt."</datetime>\n";
$err .= "\t<errornum>".$errno."</errnumber>\n";
$err .= "\t<errortype>".$errortype[$errno]."</errortype>\n";
$err .= "\t<errormsg>".$errmsg."</errormsg>\n";
$err .= "\t<scriptname>".$filename."</scriptname>\n";
$err .= "\t<scriptlinenum>".$linenum."</scriptlinenum>\n";
if (in_array($errno, $user_errors))
$err .= "\t<vartrace>".wddx_serialize_value($vars,"Variables")."</vartrace>\n";
$err .= "</errorentry>\n\n";
// for testing
// echo $err;
// save to the error log, and e-mail me if there is a critical user error
error_log($err, 3, "/usr/local/php4/error.log");
if ($errno == E_USER_ERROR)
mail("[email protected]","Critical User Error",$err);
}
function distance ($vect1, $vect2) {
if (!is_array($vect1) || !is_array($vect2)) {
trigger_error("Incorrect parameters, arrays expected", E_USER_ERROR);
return NULL;
}
if (count($vect1) != count($vect2)) {
trigger_error("Vectors need to be of the same size", E_USER_ERROR);
return NULL;
}
for ($i=0; $i<count($vect1); $i++) {
$c1 = $vect1[$i]; $c2 = $vect2[$i];
$d = 0.0;
if (!is_numeric($c1)) {
trigger_error("Coordinate $i in vector 1 is not a number, using zero",
E_USER_WARNING);
$c1 = 0.0;
}
if (!is_numeric($c2)) {
trigger_error("Coordinate $i in vector 2 is not a number, using zero",
E_USER_WARNING);
$c2 = 0.0;
}
$d += $c2*$c2 - $c1*$c1;
}
return sqrt($d);
}
$old_error_handler = set_error_handler("userErrorHandler");
// undefined constant, generates a warning
$t = I_AM_NOT_DEFINED;
// define some "vectors"
$a = array(2,3,"foo");
$b = array(5.5, 4.3, -1.6);
$c = array (1,-3);
// generate a user error
$t1 = distance($c,$b)."\n";
// generate another user error
$t2 = distance($b,"i am not an array")."\n";
// generate a warning
$t3 = distance($a,$b)."\n";
?>
</PRE
></TD
></TR
></TABLE
></DIV
></TD
></TR
></TABLE
>
This is just a simple example showing how to use the
<A
HREF="ref.errorfunc.html"
>Error Handling and Logging
functions</A
>.
</P
><P
> See also <A
HREF="function.error-reporting.html"
><B
CLASS="function"
>error_reporting()</B
></A
>,
<A
HREF="function.error-log.html"
><B
CLASS="function"
>error_log()</B
></A
>,
<A
HREF="function.set-error-handler.html"
><B
CLASS="function"
>set_error_handler()</B
></A
>,
<A
HREF="function.restore-error-handler.html"
><B
CLASS="function"
>restore_error_handler()</B
></A
>,
<A
HREF="function.trigger-error.html"
><B
CLASS="function"
>trigger_error()</B
></A
>,
<A
HREF="function.user-error.html"
><B
CLASS="function"
>user_error()</B
></A
>
</P
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="features.html"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="manual.html"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="features.images.html"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>Features</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="features.html"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>Creating and manipulating images</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>