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1 : olson 1.1 package Tracer;
2 :    
3 :     require Exporter;
4 :     @ISA = ('Exporter');
5 : parrello 1.11 @EXPORT = qw(Trace T TSetup QTrace Confess Cluck Min Max Assert Open OpenDir);
6 : parrello 1.9 @EXPORT_OK = qw(GetFile GetOptions Merge MergeOptions ParseCommand ParseRecord UnEscape Escape);
7 : olson 1.1 use strict;
8 :     use Carp qw(longmess croak);
9 :     use CGI;
10 : parrello 1.7 use FIG_Config;
11 : parrello 1.9 use PageBuilder;
12 : olson 1.1
13 :     =head1 Tracing and Debugging Helpers
14 :    
15 :     =head2 Introduction
16 :    
17 :     This package provides simple tracing for debugging and reporting purposes. To use it simply call the
18 :     L</TSetup> method to set the options and call L</Trace> to write out trace messages. Each trace
19 : parrello 1.2 message has a I<trace level> and I<category> associated with it. In addition, the tracing package itself
20 :     has a list of categories and a single trace level set by the B<TSetup> method. Only messages whose trace
21 : olson 1.1 level is less than or equal to this package's trace level and whose category is activated will
22 : parrello 1.2 be written. Thus, a higher trace level on a message indicates that the message
23 : parrello 1.10 is less likely to be seen. A higher trace level passed to B<TSetup> means more trace messages will
24 : olson 1.1 appear. To generate a trace message, use the following syntax.
25 :    
26 :     C<< Trace($message) if T(errors => 4); >>
27 :    
28 : parrello 1.2 This statement will produce a trace message if the trace level is 4 or more and the C<errors>
29 : parrello 1.3 category is active. Note that the special category C<main> is always active, so
30 : olson 1.1
31 : parrello 1.3 C<< Trace($message) if T(main => 4); >>
32 : olson 1.1
33 :     will trace if the trace level is 4 or more.
34 :    
35 :     If the category name is the same as the package name, all you need is the number. So, if the
36 :     following call is made in the B<Sprout> package, it will appear if the C<Sprout> category is
37 :     active and the trace level is 2 or more.
38 :    
39 :     C<< Trace($message) if T(2); >>
40 :    
41 : parrello 1.10 To set up tracing, you call the L</TSetup> method. The method takes as input a trace level, a list
42 : olson 1.1 of category names, and a set of options. The trace level and list of category names are
43 :     specified as a space-delimited string. Thus
44 :    
45 :     C<< TSetup('3 errors Sprout ERDB', 'HTML'); >>
46 :    
47 : parrello 1.7 sets the trace level to 3, activates the C<errors>, C<Sprout>, and C<ERDB> categories, and
48 :     specifies that messages should be output as HTML paragraphs. The parameters are formatted
49 : parrello 1.10 a little clumsily, but it makes them easier to input on a web form or in a query URL.
50 : olson 1.1
51 :     In addition to HTML and file output for trace messages, you can specify that the trace messages
52 :     be queued. The messages can then be retrieved by calling the L</QTrace> method. This approach
53 :     is useful if you are building a web page. Instead of having the trace messages interspersed with
54 :     the page output, they can be gathered together and displayed at the end of the page. This makes
55 :     it easier to debug page formatting problems.
56 :    
57 : parrello 1.4 Finally, you can specify that all trace messages be emitted as warnings.
58 :    
59 : olson 1.1 The flexibility of tracing makes it superior to simple use of directives like C<die> and C<warn>.
60 :     Tracer calls can be left in the code with minimal overhead and then turned on only when needed.
61 :     Thus, debugging information is available and easily retrieved even when the application is
62 :     being used out in the field.
63 :    
64 : parrello 1.10 There is no hard and fast rule on how to use trace levels. The following is therefore only
65 :     a suggestion.
66 :    
67 :     =over 4
68 :    
69 :     =item 0 Error
70 :    
71 :     Message indicates an error that may lead to incorrect results or that has stopped the
72 :     application entirely.
73 :    
74 :     =item 1 Warning
75 :    
76 :     Message indicates something that is unexpected but that probably did not interfere
77 :     with program execution.
78 :    
79 :     =item 2 Notice
80 :    
81 :     Message indicates the beginning or end of a major task.
82 :    
83 :     =item 3 Information
84 :    
85 :     Message indicates a subtask. In the FIG system, a subtask generally relates to a single
86 :     genome. This would be a big loop that is not expected to execute more than 500 times or so.
87 :    
88 :     =item 4 Detail
89 :    
90 :     Message indicates a low-level loop iteration.
91 :    
92 :     =back
93 :    
94 : olson 1.1 =cut
95 : parrello 1.2
96 : olson 1.1 # Declare the configuration variables.
97 :    
98 :     my $Destination = "NONE"; # Description of where to send the trace output.
99 : parrello 1.10 my $TeeFlag = 0; # TRUE if output is going to a file and to the
100 :     # standard output
101 : parrello 1.3 my %Categories = ( main => 1 );
102 : olson 1.1 # hash of active category names
103 :     my $TraceLevel = 0; # trace level; a higher trace level produces more
104 :     # messages
105 :     my @Queue = (); # queued list of trace messages.
106 : parrello 1.7 my $LastCategory = "main"; # name of the last category interrogated
107 : parrello 1.11 my $SetupCount = 0; # number of times TSetup called
108 : olson 1.1
109 :     =head2 Public Methods
110 :    
111 :     =head3 TSetup
112 :    
113 :     C<< TSetup($categoryList, $target); >>
114 :    
115 :     This method is used to specify the trace options. The options are stored as package data
116 :     and interrogated by the L</Trace> and L</T> methods.
117 :    
118 :     =over 4
119 :    
120 :     =item categoryList
121 :    
122 :     A string specifying the trace level and the categories to be traced, separated by spaces.
123 :     The trace level must come first.
124 :    
125 :     =item target
126 :    
127 :     The destination for the trace output. To send the trace output to a file, specify the file
128 :     name preceded by a ">" symbol. If a double symbol is used (">>"), then the data is appended
129 : parrello 1.10 to the file. Otherwise the file is cleared before tracing begins. Precede the first ">"
130 :     symbol with a C<+> to echo output to a file AND to the standard output. In addition to
131 :     sending the trace messages to a file, you can specify a special destination. C<HTML> will
132 :     cause tracing to the standard output with each line formatted as an HTML paragraph. C<TEXT>
133 : parrello 1.5 will cause tracing to the standard output as ordinary text. C<ERROR> will cause trace
134 : parrello 1.9 messages to be sent to the standard error output as ordinary text. C<QUEUE> will cause trace
135 : parrello 1.6 messages to be stored in a queue for later retrieval by the L</QTrace> method. C<WARN> will
136 : parrello 1.9 cause trace messages to be emitted as warnings using the B<warn> directive. C<NONE> will
137 : parrello 1.6 cause tracing to be suppressed.
138 : olson 1.1
139 :     =back
140 :    
141 :     =cut
142 :    
143 :     sub TSetup {
144 :     # Get the parameters.
145 :     my ($categoryList, $target) = @_;
146 :     # Parse the category list.
147 :     my @categoryData = split /\s+/, $categoryList;
148 :     # Extract the trace level.
149 :     $TraceLevel = shift @categoryData;
150 :     # Build the category hash.
151 :     for my $category (@categoryData) {
152 :     $Categories{$category} = 1;
153 :     }
154 :     # Now we need to process the destination information. The most important special
155 : parrello 1.10 # cases are the single ">", which requires we clear the file first, and the
156 :     # "+" prefix which indicates a double echo.
157 :     if ($target =~ m/^\+?>>?/) {
158 :     if ($target =~ m/^\+/) {
159 :     $TeeFlag = 1;
160 :     $target = substr($target, 1);
161 :     }
162 :     if ($target =~ m/^>[^>]/) {
163 :     open TRACEFILE, $target;
164 :     print TRACEFILE Now() . " Tracing initialized.\n";
165 :     close TRACEFILE;
166 :     $Destination = ">$target";
167 :     } else {
168 :     $Destination = $target;
169 :     }
170 : olson 1.1 } else {
171 :     $Destination = uc($target);
172 :     }
173 : parrello 1.11 # Increment the setup counter.
174 :     $SetupCount++;
175 :     }
176 :    
177 :     =head3 Setups
178 :    
179 :     C<< my $count = Tracer::Setups(); >>
180 :    
181 :     Return the number of times L</TSetup> has been called.
182 :    
183 :     This method allows for the creation of conditional tracing setups where, for example, we
184 :     may want to set up tracing if nobody else has done it before us.
185 :    
186 :     =cut
187 :    
188 :     sub Setups {
189 :     return $SetupCount;
190 : olson 1.1 }
191 :    
192 : parrello 1.10 =head3 Open
193 :    
194 :     C<< my $handle = Open($fileHandle, $fileSpec, $message); >>
195 :    
196 : parrello 1.11 Open a file.
197 : parrello 1.10
198 :     The I<$fileSpec> is essentially the second argument of the PERL C<open>
199 :     function. The mode is specified using Unix-like shell information. So, for
200 :     example,
201 :    
202 :     Open(\*LOGFILE, '>>/usr/spool/news/twitlog', "Could not open twit log.");
203 :    
204 :     would open for output appended to the specified file, and
205 :    
206 :     Open(\*DATASTREAM, "| sort -u >$outputFile", "Could not open $outputFile.");
207 :    
208 :     would open a pipe that sorts the records written and removes duplicates. Note
209 : parrello 1.11 the use of file handle syntax in the Open call. To use anonymous file handles,
210 :     code as follows.
211 : parrello 1.10
212 :     my $logFile = Open(undef, '>>/usr/spool/news/twitlog', "Could not open twit log.");
213 :    
214 : parrello 1.11 The I<$message> parameter is used if the open fails. If it is set to C<0>, then
215 :     the open returns TRUE if successful and FALSE if an error occurred. Otherwise, a
216 :     failed open will throw an exception and the third parameter will be used to construct
217 :     an error message. If the parameter is omitted, a standard message is constructed
218 :     using the file spec.
219 : parrello 1.10
220 :     Could not open "/usr/spool/news/twitlog"
221 :    
222 :     Note that the mode characters are automatically cleaned from the file name.
223 :     The actual error message from the file system will be captured and appended to the
224 :     message in any case.
225 :    
226 :     Could not open "/usr/spool/news/twitlog": file not found.
227 :    
228 :     In some versions of PERL the only error message we get is a number, which
229 :     corresponds to the C++ C<errno> value.
230 :    
231 :     Could not open "/usr/spool/news/twitlog": 6.
232 :    
233 :     =over 4
234 :    
235 :     =item fileHandle
236 :    
237 :     File handle. If this parameter is C<undef>, a file handle will be generated
238 :     and returned as the value of this method.
239 :    
240 :     =item fileSpec
241 :    
242 :     File name and mode, as per the PERL C<open> function.
243 :    
244 :     =item message (optional)
245 :    
246 :     Error message to use if the open fails. If omitted, a standard error message
247 :     will be generated. In either case, the error information from the file system
248 : parrello 1.11 is appended to the message. To specify a conditional open that does not throw
249 :     an error if it fails, use C<0>.
250 : parrello 1.10
251 :     =item RETURN
252 :    
253 : parrello 1.11 Returns the name of the file handle assigned to the file, or C<undef> if the
254 :     open failed.
255 : parrello 1.10
256 :     =back
257 :    
258 :     =cut
259 :    
260 :     sub Open {
261 :     # Get the parameters.
262 :     my ($fileHandle, $fileSpec, $message) = @_;
263 :     # Attempt to open the file.
264 :     my $rv = open $fileHandle, $fileSpec;
265 :     # If the open failed, generate an error message.
266 :     if (! $rv) {
267 :     # Save the system error message.
268 :     my $sysMessage = $!;
269 : parrello 1.11 # See if we need a default message.
270 : parrello 1.10 if (!$message) {
271 : parrello 1.11 # Clean any obvious mode characters and leading spaces from the
272 :     # filename.
273 :     my ($fileName) = FindNamePart($fileSpec);
274 :     $message = "Could not open \"$fileName\"";
275 : parrello 1.10 }
276 :     # Terminate with an error using the supplied message and the
277 :     # error message from the file system.
278 :     Confess("$message: $!");
279 :     }
280 :     # Return the file handle.
281 :     return $fileHandle;
282 :     }
283 :    
284 : parrello 1.11 =head3 FindNamePart
285 :    
286 :     C<< my ($fileName, $start, $len) = Tracer::FindNamePart($fileSpec); >>
287 :    
288 :     Extract the portion of a file specification that contains the file name.
289 :    
290 :     A file specification is the string passed to an C<open> call. It specifies the file
291 :     mode and name. In a truly complex situation, it can specify a pipe sequence. This
292 :     method assumes that the file name is whatever follows the first angle bracket
293 :     sequence. So, for example, in the following strings the file name is
294 :     C</usr/fig/myfile.txt>.
295 :    
296 :     >>/usr/fig/myfile.txt
297 :     </usr/fig/myfile.txt
298 :     | sort -u > /usr/fig/myfile.txt
299 :    
300 :     If the method cannot find a file name using its normal methods, it will return the
301 :     whole incoming string.
302 :    
303 :     =over 4
304 :    
305 :     =item fileSpec
306 :    
307 :     File specification string from which the file name is to be extracted.
308 :    
309 :     =item RETURN
310 :    
311 :     Returns a three-element list. The first element contains the file name portion of
312 :     the specified string, or the whole string if a file name cannot be found via normal
313 :     methods. The second element contains the start position of the file name portion and
314 :     the third element contains the length.
315 :    
316 :     =back
317 :    
318 :     =cut
319 :     #: Return Type $;
320 :     sub FindNamePart {
321 :     # Get the parameters.
322 :     my ($fileSpec) = @_;
323 :     # Default to the whole input string.
324 :     my ($retVal, $pos, $len) = ($fileSpec, 0, length $fileSpec);
325 :     # Parse out the file name if we can.
326 :     if ($fileSpec =~ m/(<|>>?)(.+?)(\s*)$/) {
327 :     $retVal = $2;
328 :     $len = length $retVal;
329 :     $pos = (length $fileSpec) - (length $3) - $len;
330 :     }
331 :     # Return the result.
332 :     return ($retVal, $pos, $len);
333 :     }
334 :    
335 :     =head3 OpenDir
336 :    
337 :     C<< my @files = OpenDir($dirName, $filtered); >>
338 :    
339 :     Open a directory and return all the file names. This function essentially performs
340 :     the functions of an C<opendir> and C<readdir>. If the I<$filtered> parameter is
341 :     set to TRUE, all filenames beginning with a period (C<.>) will be filtered out of
342 :     the return list. If the directory does not open, an exception is thrown. So,
343 :     for example,
344 :    
345 :     my @files = OpenDir("/Volumes/fig/contigs", 1);
346 :    
347 :     is effectively the same as
348 :    
349 :     opendir(TMP, "/Volumes/fig/contigs") || Confess("Could not open /Volumes/fig/contigs.");
350 :     my @files = grep { $_ !~ /^\./ } readdir(TMP);
351 :    
352 :     Similarly, the following code
353 :    
354 :     my @files = grep { $_ =~ /^\d/ } OpenDir("/Volumes/fig/orgs");
355 :    
356 :     Returns the names of all files in C</Volumes/fig/orgs> that begin with digits and
357 :     automatically throws an error if the directory fails to open.
358 :    
359 :     =over 4
360 :    
361 :     =item dirName
362 :    
363 :     Name of the directory to open.
364 :    
365 :     =item filtered
366 :    
367 :     TRUE if files whose names begin with a period (C<.>) should be automatically removed
368 :     from the list, else FALSE.
369 :    
370 :     =back
371 :    
372 :     =cut
373 :     #: Return Type @;
374 :     sub OpenDir {
375 :     # Get the parameters.
376 :     my ($dirName, $filtered) = @_;
377 :     # Declare the return variable.
378 :     my @retVal;
379 :     # Open the directory.
380 :     if (opendir(my $dirHandle, $dirName)) {
381 :     # The directory opened successfully. Get the appropriate list according to the
382 :     # strictures of the filter parameter.
383 :     if ($filtered) {
384 :     @retVal = grep { $_ !~ /^\./ } readdir $dirHandle;
385 :     } else {
386 :     @retVal = readdir $dirHandle;
387 :     }
388 :     } else {
389 :     # Here the directory would not open.
390 :     Confess("Could not open directory $dirName.");
391 :     }
392 :     # Return the result.
393 :     return @retVal;
394 :     }
395 :    
396 : parrello 1.6 =head3 SetLevel
397 :    
398 :     C<< Tracer::SetLevel($newLevel); >>
399 :    
400 :     Modify the trace level. A higher trace level will cause more messages to appear.
401 :    
402 :     =over 4
403 :    
404 :     =item newLevel
405 :    
406 :     Proposed new trace level.
407 :    
408 :     =back
409 :    
410 :     =cut
411 :    
412 :     sub SetLevel {
413 :     $TraceLevel = $_[0];
414 :     }
415 :    
416 : olson 1.1 =head3 Now
417 :    
418 :     C<< my $string = Tracer::Now(); >>
419 :    
420 :     Return a displayable time stamp containing the local time.
421 :    
422 :     =cut
423 :    
424 :     sub Now {
425 :     my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime(time);
426 :     my $retVal = _p2($mon+1) . "/" . _p2($mday) . "/" . ($year + 1900) . " " .
427 :     _p2($hour) . ":" . _p2($min) . ":" . _p2($sec);
428 : parrello 1.2 return $retVal;
429 : olson 1.1 }
430 :    
431 :     # Pad a number to 2 digits.
432 :     sub _p2 {
433 :     my ($value) = @_;
434 :     $value = "0$value" if ($value < 10);
435 :     return $value;
436 :     }
437 :    
438 :     =head3 LogErrors
439 :    
440 :     C<< Tracer::LogErrors($fileName); >>
441 :    
442 :     Route the standard error output to a log file.
443 :    
444 :     =over 4
445 :    
446 :     =item fileName
447 :    
448 :     Name of the file to receive the error output.
449 :    
450 :     =back
451 :    
452 :     =cut
453 :    
454 :     sub LogErrors {
455 :     # Get the file name.
456 :     my ($fileName) = @_;
457 :     # Open the file as the standard error output.
458 :     open STDERR, '>', $fileName;
459 :     }
460 :    
461 : parrello 1.5 =head3 ReadOptions
462 :    
463 :     C<< my %options = Tracer::ReadOptions($fileName); >>
464 :    
465 :     Read a set of options from a file. Each option is encoded in a line of text that has the
466 :     format
467 :    
468 :     I<optionName>C<=>I<optionValue>C<; >I<comment>
469 :    
470 :     The option name must consist entirely of letters, digits, and the punctuation characters
471 : parrello 1.9 C<.> and C<_>, and is case sensitive. Blank lines and lines in which the first nonblank
472 :     character is a semi-colon will be ignored. The return hash will map each option name to
473 : parrello 1.5 the corresponding option value.
474 :    
475 :     =over 4
476 :    
477 :     =item fileName
478 :    
479 :     Name of the file containing the option data.
480 :    
481 :     =item RETURN
482 :    
483 :     Returns a hash mapping the option names specified in the file to their corresponding option
484 :     value.
485 :    
486 :     =back
487 :    
488 :     =cut
489 :    
490 :     sub ReadOptions {
491 :     # Get the parameters.
492 :     my ($fileName) = @_;
493 :     # Open the file.
494 :     (open CONFIGFILE, "<$fileName") || Confess("Could not open option file $fileName.");
495 :     # Count the number of records read.
496 :     my ($records, $comments) = 0;
497 :     # Create the return hash.
498 :     my %retVal = ();
499 :     # Loop through the file, accumulating key-value pairs.
500 :     while (my $line = <CONFIGFILE>) {
501 :     # Denote we've read a line.
502 :     $records++;
503 :     # Determine the line type.
504 :     if ($line =~ /^\s*[\n\r]/) {
505 :     # A blank line is a comment.
506 :     $comments++;
507 :     } elsif ($line =~ /^\s*([A-Za-z0-9_\.]+)=([^;]*);/) {
508 :     # Here we have an option assignment.
509 :     retVal{$1} = $2;
510 :     } elsif ($line =~ /^\s*;/) {
511 :     # Here we have a text comment.
512 :     $comments++;
513 :     } else {
514 :     # Here we have an invalid line.
515 :     Trace("Invalid option statement in record $records.") if T(0);
516 :     }
517 :     }
518 :     # Return the hash created.
519 :     return %retVal;
520 :     }
521 :    
522 : olson 1.1 =head3 GetOptions
523 :    
524 :     C<< Tracer::GetOptions(\%defaults, \%options); >>
525 :    
526 :     Merge a specified set of options into a table of defaults. This method takes two hash references
527 :     as input and uses the data from the second to update the first. If the second does not exist,
528 :     there will be no effect. An error will be thrown if one of the entries in the second hash does not
529 :     exist in the first.
530 :    
531 :     Consider the following example.
532 :    
533 :     C<< my $optionTable = GetOptions({ dbType => 'mySQL', trace => 0 }, $options); >>
534 :    
535 :     In this example, the variable B<$options> is expected to contain at most two options-- B<dbType> and
536 :     B<trace>. The default database type is C<mySQL> and the default trace level is C<0>. If the value of
537 :     B<$options> is C<< {dbType => 'Oracle'} >>, then the database type will be changed to C<Oracle> and
538 :     the trace level will remain at 0. If B<$options> is undefined, then the database type and trace level
539 :     will remain C<mySQL> and C<0>. If, on the other hand, B<$options> is defined as
540 :    
541 :     C<< {databaseType => 'Oracle'} >>
542 :    
543 :     an error will occur because the B<databaseType> option does not exist.
544 :    
545 :     =over 4
546 :    
547 :     =item defaults
548 :    
549 :     Table of default option values.
550 :    
551 :     =item options
552 :    
553 :     Table of overrides, if any.
554 :    
555 :     =item RETURN
556 :    
557 :     Returns a reference to the default table passed in as the first parameter.
558 :    
559 :     =back
560 :    
561 :     =cut
562 :    
563 :     sub GetOptions {
564 :     # Get the parameters.
565 :     my ($defaults, $options) = @_;
566 :     # Check for overrides.
567 :     if ($options) {
568 :     # Loop through the overrides.
569 :     while (my ($option, $setting) = each %{$options}) {
570 :     # Insure this override exists.
571 :     if (!exists $defaults->{$option}) {
572 :     croak "Unrecognized option $option encountered.";
573 :     } else {
574 :     # Apply the override.
575 :     $defaults->{$option} = $setting;
576 :     }
577 :     }
578 :     }
579 :     # Return the merged table.
580 :     return $defaults;
581 :     }
582 :    
583 :     =head3 MergeOptions
584 :    
585 :     C<< Tracer::MergeOptions(\%table, \%defaults); >>
586 :    
587 :     Merge default values into a hash table. This method looks at the key-value pairs in the
588 :     second (default) hash, and if a matching key is not found in the first hash, the default
589 :     pair is copied in. The process is similar to L</GetOptions>, but there is no error-
590 :     checking and no return value.
591 :    
592 :     =over 4
593 :    
594 :     =item table
595 :    
596 :     Hash table to be updated with the default values.
597 :    
598 :     =item defaults
599 :    
600 :     Default values to be merged into the first hash table if they are not already present.
601 :    
602 :     =back
603 :    
604 :     =cut
605 :    
606 :     sub MergeOptions {
607 :     # Get the parameters.
608 :     my ($table, $defaults) = @_;
609 :     # Loop through the defaults.
610 :     while (my ($key, $value) = each %{$defaults}) {
611 :     if (!exists $table->{$key}) {
612 :     $table->{$key} = $value;
613 :     }
614 :     }
615 :     }
616 :    
617 :     =head3 Trace
618 :    
619 :     C<< Trace($message); >>
620 :    
621 :     Write a trace message to the target location specified in L</TSetup>. If there has not been
622 :     any prior call to B<TSetup>.
623 :    
624 :     =over 4
625 :    
626 :     =item message
627 :    
628 :     Message to write.
629 :    
630 :     =back
631 :    
632 :     =cut
633 :    
634 :     sub Trace {
635 :     # Get the parameters.
636 :     my ($message) = @_;
637 :     # Get the timestamp.
638 :     my $timeStamp = Now();
639 : parrello 1.9 # Format the message. Note we strip off any line terminators at the end.
640 :     my $formatted = "$timeStamp <$LastCategory>: " . Strip($message);
641 : olson 1.1 # Process according to the destination.
642 :     if ($Destination eq "TEXT") {
643 :     # Write the message to the standard output.
644 : parrello 1.5 print "$formatted\n";
645 :     } elsif ($Destination eq "ERROR") {
646 :     # Write the message to the error output.
647 :     print STDERR "$formatted\n";
648 : olson 1.1 } elsif ($Destination eq "QUEUE") {
649 :     # Push the message into the queue.
650 : parrello 1.5 push @Queue, "$formatted";
651 : olson 1.1 } elsif ($Destination eq "HTML") {
652 :     # Convert the message to HTML and write it to the standard output.
653 :     my $escapedMessage = CGI::escapeHTML($message);
654 : parrello 1.5 print "<p>$formatted</p>\n";
655 : parrello 1.4 } elsif ($Destination eq "WARN") {
656 :     # Emit the message as a warning.
657 :     warn $message;
658 : olson 1.1 } elsif ($Destination =~ m/^>>/) {
659 :     # Write the trace message to an output file.
660 :     open TRACING, $Destination;
661 : parrello 1.5 print TRACING "$formatted\n";
662 : olson 1.1 close TRACING;
663 : parrello 1.10 # If the Tee flag is on, echo it to the standard output.
664 :     if ($TeeFlag) {
665 :     print "$formatted\n";
666 :     }
667 : olson 1.1 }
668 :     }
669 :    
670 :     =head3 T
671 :    
672 : parrello 1.2 C<< my $switch = T($category, $traceLevel); >>
673 : olson 1.1
674 :     or
675 : parrello 1.2
676 : olson 1.1 C<< my $switch = T($traceLevel); >>
677 :    
678 :     Return TRUE if the trace level is at or above a specified value and the specified category
679 :     is active, else FALSE. If no category is specified, the caller's package name is used.
680 :    
681 :     =over 4
682 :    
683 :     =item category
684 :    
685 :     Category to which the message belongs. If not specified, the caller's package name is
686 :     used.
687 :    
688 :     =item traceLevel
689 :    
690 :     Relevant tracing level.
691 :    
692 :     =item RETURN
693 :    
694 :     TRUE if a message at the specified trace level would appear in the trace, else FALSE.
695 :    
696 :     =back
697 :    
698 :     =cut
699 :    
700 :     sub T {
701 :     # Declare the return variable.
702 :     my $retVal = 0;
703 :     # Only proceed if tracing is turned on.
704 :     if ($Destination ne "NONE") {
705 :     # Get the parameters.
706 :     my ($category, $traceLevel) = @_;
707 :     if (!defined $traceLevel) {
708 :     # Here we have no category, so we need to get the calling package.
709 :     $traceLevel = $category;
710 :     my ($package, $fileName, $line) = caller;
711 : parrello 1.3 # If there is no calling package, we default to "main".
712 : olson 1.1 if (!$package) {
713 : parrello 1.3 $category = "main";
714 : olson 1.1 } else {
715 :     $category = $package;
716 :     }
717 :     }
718 : parrello 1.7 # Save the category name.
719 :     $LastCategory = $category;
720 :     # Use the category and tracelevel to compute the result.
721 : olson 1.1 $retVal = ($traceLevel <= $TraceLevel && exists $Categories{$category});
722 : parrello 1.3 }
723 : olson 1.1 # Return the computed result.
724 : parrello 1.3 return $retVal;
725 : olson 1.1 }
726 :    
727 :     =head3 ParseCommand
728 :    
729 :     C<< my ($options, @arguments) = Tracer::ParseCommand(\%optionTable, @inputList); >>
730 :    
731 :     Parse a command line consisting of a list of parameters. The initial parameters may be option
732 : parrello 1.2 specifiers of the form C<->I<option> or C<->I<option>C<=>I<value>. The options are stripped
733 :     off and merged into a table of default options. The remainder of the command line is
734 : olson 1.1 returned as a list of positional arguments. For example, consider the following invocation.
735 :    
736 :     C<< my ($options, @arguments) = ParseCommand({ errors => 0, logFile => 'trace.log'}, @words); >>
737 :    
738 :     In this case, the list @words will be treated as a command line. There are two options available,
739 :     B<errors> and B<logFile>. If @words has the following format
740 :    
741 :     C<< -logFile=error.log apple orange rutabaga >>
742 :    
743 :     then at the end of the invocation, C<$options> will be
744 :    
745 :     C<< { errors => 0, logFile => 'error.log' } >>
746 :    
747 :     and C<@arguments> will contain
748 :    
749 :     C<< apple orange rutabaga >>
750 :    
751 : parrello 1.2 The parser allows for some escape sequences. See L</UnEscape> for a description. There is no
752 : olson 1.1 support for quote characters.
753 :    
754 :     =over 4
755 :    
756 :     =item optionTable
757 :    
758 :     Table of default options.
759 :    
760 :     =item inputList
761 :    
762 :     List of words on the command line.
763 :    
764 :     =item RETURN
765 :    
766 :     Returns a reference to the option table and a list of the positional arguments.
767 :    
768 :     =back
769 :    
770 :     =cut
771 :    
772 :     sub ParseCommand {
773 :     # Get the parameters.
774 :     my ($optionTable, @inputList) = @_;
775 :     # Process any options in the input list.
776 :     my %overrides = ();
777 :     while ((@inputList > 0) && ($inputList[0] =~ /^-/)) {
778 :     # Get the current option.
779 :     my $arg = shift @inputList;
780 :     # Pull out the option name.
781 :     $arg =~ /^-([^=]*)/g;
782 :     my $name = $1;
783 :     # Check for an option value.
784 :     if ($arg =~ /\G=(.*)$/g) {
785 :     # Here we have a value for the option.
786 :     $overrides{$name} = UnEscape($1);
787 :     } else {
788 :     # Here there is no value, so we use 1.
789 :     $overrides{$name} = 1;
790 :     }
791 :     }
792 :     # Merge the options into the defaults.
793 :     GetOptions($optionTable, \%overrides);
794 :     # Translate the remaining parameters.
795 :     my @retVal = ();
796 :     for my $inputParm (@inputList) {
797 :     push @retVal, UnEscape($inputParm);
798 :     }
799 :     # Return the results.
800 :     return ($optionTable, @retVal);
801 :     }
802 :    
803 : parrello 1.9 =head3 Escape
804 :    
805 :     C<< my $codedString = Tracer::Escape($realString); >>
806 :    
807 :     Escape a string for use in a command length. Spaces will be replaced by C<\b>,
808 :     tabs replaced by C<\t>, new-lines replaced by C<\n>, and backslashes will be
809 :     doubled. The effect is to exactly reverse the effect of L</UnEscape>.
810 :    
811 :     =over 4
812 :    
813 :     =item realString
814 :    
815 :     String to escape.
816 :    
817 :     =item RETURN
818 :    
819 :     Escaped equivalent of the real string.
820 :    
821 :     =back
822 :    
823 :     =cut
824 :    
825 :     sub Escape {
826 :     # Get the parameter.
827 :     my ($realString) = @_;
828 :     # Initialize the return variable.
829 :     my $retVal = "";
830 :     # Loop through the parameter string, looking for sequences to escape.
831 :     while (length $realString > 0) {
832 :     # Look for the first sequence to escape.
833 :     if ($realString =~ /^(.*?)([ \n\t\\])/) {
834 :     # Here we found it. The text preceding the sequence is in $1. The sequence
835 :     # itself is in $2. First, move the clear text to the return variable.
836 :     $retVal .= $1;
837 :     $realString = substr $realString, (length $2 + length $1);
838 :     # Encode the escape sequence.
839 :     my $char = $2;
840 :     $char =~ tr/ \t\n/btn/;
841 :     $retVal .= "\\" . $char;
842 :     } else {
843 :     # Here there are no more escape sequences. The rest of the string is
844 :     # transferred unmodified.
845 :     $retVal .= $realString;
846 :     $realString = "";
847 :     }
848 :     }
849 :     # Return the result.
850 :     return $retVal;
851 :     }
852 :    
853 : olson 1.1 =head3 UnEscape
854 :    
855 :     C<< my $realString = Tracer::UnEscape($codedString); >>
856 :    
857 :     Replace escape sequences with their actual equivalents. C<\b> will be replaced by a space,
858 :     C<\t> by a tab, C<\n> by a new-line character, and C<\\> by a back-slash.
859 :    
860 :     =over 4
861 :    
862 :     =item codedString
863 :    
864 :     String to un-escape.
865 :    
866 :     =item RETURN
867 :    
868 :     Returns a copy of the original string with the escape sequences converted to their actual
869 :     values.
870 :    
871 :     =back
872 :    
873 :     =cut
874 :    
875 :     sub UnEscape {
876 :     # Get the parameter.
877 :     my ($codedString) = @_;
878 :     # Initialize the return variable.
879 :     my $retVal = "";
880 : parrello 1.9 # Only proceed if the incoming string is nonempty.
881 :     if (defined $codedString) {
882 :     # Loop through the parameter string, looking for escape sequences. We can't do
883 :     # translating because it causes problems with the escaped slash. ("\\b" becomes
884 :     # "\ " no matter what we do.)
885 :     while (length $codedString > 0) {
886 :     # Look for the first escape sequence.
887 :     if ($codedString =~ /^(.*?)\\(\\|b|n|t)/) {
888 :     # Here we found it. The text preceding the sequence is in $1. The sequence
889 :     # itself is in $2. First, move the clear text to the return variable.
890 :     $retVal .= $1;
891 :     $codedString = substr $codedString, (2 + length $1);
892 :     # Decode the escape sequence.
893 :     my $char = $2;
894 :     $char =~ tr/\\btn/\\ \t\n/;
895 :     $retVal .= $char;
896 :     } else {
897 :     # Here there are no more escape sequences. The rest of the string is
898 :     # transferred unmodified.
899 :     $retVal .= $codedString;
900 :     $codedString = "";
901 :     }
902 : olson 1.1 }
903 :     }
904 :     # Return the result.
905 : parrello 1.2 return $retVal;
906 : olson 1.1 }
907 :    
908 :     =head3 ParseRecord
909 :    
910 :     C<< my @fields = Tracer::ParseRecord($line); >>
911 :    
912 :     Parse a tab-delimited data line. The data line is split into field values. Embedded tab
913 :     and new-line characters in the data line must be represented as C<\t> and C<\n>, respectively.
914 :     These will automatically be converted.
915 :    
916 :     =over 4
917 :    
918 :     =item line
919 :    
920 :     Line of data containing the tab-delimited fields.
921 :    
922 :     =item RETURN
923 :    
924 :     Returns a list of the fields found in the data line.
925 :    
926 :     =back
927 :    
928 :     =cut
929 :    
930 :     sub ParseRecord {
931 :     # Get the parameter.
932 :     my ($line) = @_;
933 :     # Remove the trailing new-line, if any.
934 :     chomp $line;
935 :     # Split the line read into pieces using the tab character.
936 :     my @retVal = split /\t/, $line;
937 :     # Trim and fix the escapes in each piece.
938 :     for my $value (@retVal) {
939 :     # Trim leading whitespace.
940 :     $value =~ s/^\s+//;
941 :     # Trim trailing whitespace.
942 :     $value =~ s/\s+$//;
943 :     # Delete the carriage returns.
944 :     $value =~ s/\r//g;
945 :     # Convert the escapes into their real values.
946 :     $value =~ s/\\t/"\t"/ge;
947 :     $value =~ s/\\n/"\n"/ge;
948 :     }
949 :     # Return the result.
950 :     return @retVal;
951 :     }
952 :    
953 :     =head3 Merge
954 :    
955 :     C<< my @mergedList = Tracer::Merge(@inputList); >>
956 :    
957 :     Sort a list of strings and remove duplicates.
958 :    
959 :     =over 4
960 :    
961 :     =item inputList
962 :    
963 :     List of scalars to sort and merge.
964 :    
965 :     =item RETURN
966 :    
967 :     Returns a list containing the same elements sorted in ascending order with duplicates
968 :     removed.
969 :    
970 :     =back
971 :    
972 :     =cut
973 :    
974 :     sub Merge {
975 :     # Get the input list in sort order.
976 :     my @inputList = sort @_;
977 :     # Only proceed if the list has at least two elements.
978 :     if (@inputList > 1) {
979 :     # Now we want to move through the list splicing out duplicates.
980 :     my $i = 0;
981 :     while ($i < @inputList) {
982 :     # Get the current entry.
983 :     my $thisEntry = $inputList[$i];
984 :     # Find out how many elements duplicate the current entry.
985 :     my $j = $i + 1;
986 :     my $dup1 = $i + 1;
987 :     while ($j < @inputList && $inputList[$j] eq $thisEntry) { $j++; };
988 :     # If the number is nonzero, splice out the duplicates found.
989 :     if ($j > $dup1) {
990 :     splice @inputList, $dup1, $j - $dup1;
991 :     }
992 :     # Now the element at position $dup1 is different from the element before it
993 :     # at position $i. We push $i forward one position and start again.
994 :     $i++;
995 :     }
996 :     }
997 :     # Return the merged list.
998 :     return @inputList;
999 :     }
1000 :    
1001 :     =head3 GetFile
1002 :    
1003 : parrello 1.6 C<< my @fileContents = Tracer::GetFile($fileName); >>
1004 : olson 1.1
1005 :     Return the entire contents of a file.
1006 :    
1007 :     =over 4
1008 :    
1009 :     =item fileName
1010 :    
1011 :     Name of the file to read.
1012 :    
1013 :     =item RETURN
1014 :    
1015 : parrello 1.6 In a list context, returns the entire file as a list with the line terminators removed.
1016 :     In a scalar context, returns the entire file as a string.
1017 : olson 1.1
1018 :     =back
1019 :    
1020 :     =cut
1021 :    
1022 :     sub GetFile {
1023 :     # Get the parameters.
1024 :     my ($fileName) = @_;
1025 :     # Declare the return variable.
1026 : parrello 1.6 my @retVal = ();
1027 : olson 1.1 # Open the file for input.
1028 :     my $ok = open INPUTFILE, "<$fileName";
1029 :     if (!$ok) {
1030 : parrello 1.6 # If we had an error, trace it. We will automatically return a null value.
1031 :     Trace("Could not open \"$fileName\" for input.") if T(0);
1032 : olson 1.1 } else {
1033 : parrello 1.9 # Read the whole file into the return variable, stripping off any terminator
1034 : parrello 1.6 # characters.
1035 :     my $lineCount = 0;
1036 :     while (my $line = <INPUTFILE>) {
1037 :     $lineCount++;
1038 : parrello 1.9 $line = Strip($line);
1039 : parrello 1.6 push @retVal, $line;
1040 : olson 1.1 }
1041 :     # Close it.
1042 :     close INPUTFILE;
1043 : parrello 1.6 my $actualLines = @retVal;
1044 : olson 1.1 }
1045 : parrello 1.6 # Return the file's contents in the desired format.
1046 : parrello 1.9 if (wantarray) {
1047 : parrello 1.6 return @retVal;
1048 :     } else {
1049 :     return join "\n", @retVal;
1050 :     }
1051 : olson 1.1 }
1052 :    
1053 :     =head3 QTrace
1054 :    
1055 :     C<< my $data = QTrace($format); >>
1056 :    
1057 :     Return the queued trace data in the specified format.
1058 :    
1059 :     =over 4
1060 :    
1061 :     =item format
1062 :    
1063 :     C<html> to format the data as an HTML list, C<text> to format it as straight text.
1064 :    
1065 :     =back
1066 :    
1067 :     =cut
1068 :    
1069 :     sub QTrace {
1070 :     # Get the parameter.
1071 :     my ($format) = @_;
1072 :     # Create the return variable.
1073 :     my $retVal = "";
1074 :     # Process according to the format.
1075 :     if ($format =~ m/^HTML$/i) {
1076 :     # Convert the queue into an HTML list.
1077 :     $retVal = "<ul>\n";
1078 :     for my $line (@Queue) {
1079 :     my $escapedLine = CGI::escapeHTML($line);
1080 :     $retVal .= "<li>$escapedLine</li>\n";
1081 :     }
1082 :     $retVal .= "</ul>\n";
1083 :     } elsif ($format =~ m/^TEXT$/i) {
1084 :     # Convert the queue into a list of text lines.
1085 :     $retVal = join("\n", @Queue) . "\n";
1086 :     }
1087 :     # Clear the queue.
1088 :     @Queue = ();
1089 :     # Return the formatted list.
1090 :     return $retVal;
1091 :     }
1092 :    
1093 :     =head3 Confess
1094 :    
1095 :     C<< Confess($message); >>
1096 :    
1097 :     Trace the call stack and abort the program with the specified message. The stack
1098 :     trace will only appear if the trace level for this package is 1 or more. When used with
1099 : parrello 1.9 the OR operator and the L</Assert> method, B<Confess> can function as a debugging assert.
1100 : parrello 1.6 So, for example
1101 : olson 1.1
1102 : parrello 1.6 C<< Assert($recNum >= 0) || Confess("Invalid record number $recNum."); >>
1103 : olson 1.1
1104 :     Will abort the program with a stack trace if the value of C<$recNum> is negative.
1105 :    
1106 :     =over 4
1107 :    
1108 :     =item message
1109 :    
1110 :     Message to include in the trace.
1111 :    
1112 :     =back
1113 :    
1114 :     =cut
1115 :    
1116 :     sub Confess {
1117 :     # Get the parameters.
1118 :     my ($message) = @_;
1119 :     # Trace the call stack.
1120 :     Cluck($message) if T(1);
1121 :     # Abort the program.
1122 : parrello 1.5 croak(">>> $message");
1123 : olson 1.1 }
1124 :    
1125 : parrello 1.6 =head3 Assert
1126 :    
1127 :     C<< Assert($condition1, $condition2, ... $conditionN); >>
1128 :    
1129 :     Return TRUE if all the conditions are true. This method can be used in conjunction with
1130 :     the OR operator and the L</Confess> method, B<Assert> can function as a debugging assert.
1131 :     So, for example
1132 :    
1133 :     C<< Assert($recNum >= 0) || Confess("Invalid record number $recNum."); >>
1134 :    
1135 :     Will abort the program with a stack trace if the value of C<$recNum> is negative.
1136 :    
1137 :     =cut
1138 :     sub Assert {
1139 :     my $retVal = 1;
1140 :     LOOP: for my $condition (@_) {
1141 :     if (! $condition) {
1142 :     $retVal = 0;
1143 :     last LOOP;
1144 :     }
1145 :     }
1146 :     return $retVal;
1147 :     }
1148 :    
1149 : olson 1.1 =head3 Cluck
1150 :    
1151 :     C<< Cluck($message); >>
1152 :    
1153 :     Trace the call stack. Note that for best results, you should qualify the call with a
1154 :     trace condition. For example,
1155 :    
1156 :     C<< Cluck("Starting record parse.") if T(3); >>
1157 :    
1158 :     will only trace the stack if the trace level for the package is 3 or more.
1159 :    
1160 :     =over 4
1161 :    
1162 :     =item message
1163 :    
1164 :     Message to include in the trace.
1165 :    
1166 :     =back
1167 :    
1168 :     =cut
1169 :    
1170 :     sub Cluck {
1171 :     # Get the parameters.
1172 :     my ($message) = @_;
1173 : parrello 1.5 # Trace what's happening.
1174 :     Trace("Stack trace for event: $message");
1175 : olson 1.1 my $confession = longmess($message);
1176 : parrello 1.5 # Convert the confession to a series of trace messages. Note we skip any
1177 :     # messages relating to calls into Tracer.
1178 : olson 1.1 for my $line (split /\s*\n/, $confession) {
1179 : parrello 1.5 Trace($line) if ($line !~ /Tracer\.pm/);
1180 : olson 1.1 }
1181 :     }
1182 :    
1183 : parrello 1.5 =head3 Min
1184 :    
1185 :     C<< my $min = Min($value1, $value2, ... $valueN); >>
1186 :    
1187 :     Return the minimum argument. The arguments are treated as numbers.
1188 :    
1189 :     =over 4
1190 :    
1191 :     =item $value1, $value2, ... $valueN
1192 :    
1193 :     List of numbers to compare.
1194 :    
1195 :     =item RETURN
1196 :    
1197 :     Returns the lowest number in the list.
1198 :    
1199 :     =back
1200 :    
1201 :     =cut
1202 :    
1203 :     sub Min {
1204 :     # Get the parameters. Note that we prime the return value with the first parameter.
1205 :     my ($retVal, @values) = @_;
1206 :     # Loop through the remaining parameters, looking for the lowest.
1207 :     for my $value (@values) {
1208 :     if ($value < $retVal) {
1209 :     $retVal = $value;
1210 :     }
1211 :     }
1212 :     # Return the minimum found.
1213 :     return $retVal;
1214 :     }
1215 :    
1216 :     =head3 Max
1217 :    
1218 :     C<< my $max = Max($value1, $value2, ... $valueN); >>
1219 :    
1220 :     Return the maximum argument. The arguments are treated as numbers.
1221 :    
1222 :     =over 4
1223 :    
1224 :     =item $value1, $value2, ... $valueN
1225 :    
1226 :     List of numbers to compare.
1227 :    
1228 :     =item RETURN
1229 :    
1230 :     Returns the highest number in the list.
1231 :    
1232 :     =back
1233 :    
1234 :     =cut
1235 :    
1236 :     sub Max {
1237 :     # Get the parameters. Note that we prime the return value with the first parameter.
1238 :     my ($retVal, @values) = @_;
1239 :     # Loop through the remaining parameters, looking for the highest.
1240 :     for my $value (@values) {
1241 :     if ($value > $retVal) {
1242 :     $retVal = $value;
1243 :     }
1244 :     }
1245 :     # Return the maximum found.
1246 :     return $retVal;
1247 :     }
1248 :    
1249 :     =head3 AddToListMap
1250 :    
1251 :     C<< Tracer::AddToListMap(\%hash, $key, $value); >>
1252 :    
1253 :     Add a key-value pair to a hash of lists. If no value exists for the key, a singleton list
1254 :     is created for the key. Otherwise, the new value is pushed onto the list.
1255 :    
1256 :     =over 4
1257 :    
1258 :     =item hash
1259 :    
1260 :     Reference to the target hash.
1261 :    
1262 :     =item key
1263 :    
1264 :     Key for which the value is to be added.
1265 :    
1266 :     =item value
1267 :    
1268 :     Value to add to the key's value list.
1269 :    
1270 :     =back
1271 :    
1272 :     =cut
1273 :    
1274 :     sub AddToListMap {
1275 :     # Get the parameters.
1276 :     my ($hash, $key, $value) = @_;
1277 :     # Process according to whether or not the key already has a value.
1278 :     if (! exists $hash->{$key}) {
1279 :     $hash->{$key} = [$value];
1280 :     } else {
1281 :     push @{$hash->{$key}}, $value;
1282 :     }
1283 :     }
1284 : olson 1.1
1285 : parrello 1.7 =head3 DebugMode
1286 :    
1287 :     C<< if (Tracer::DebugMode) { ...code... } >>
1288 :    
1289 :     Return TRUE if debug mode has been turned on in FIG_Config, else output
1290 :     an error page and return FALSE.
1291 :    
1292 :     Certain CGI scripts are too dangerous to exist in the production
1293 :     environment. This method provides a simple way to prevent them
1294 :     from working unless they are explicitly turned on in the configuration
1295 :     file by setting C<$FIG_Config::debug_mode> to 1. If debugging mode
1296 :     is not turned on, an error web page will be output.
1297 :    
1298 :     =cut
1299 :    
1300 :     sub DebugMode {
1301 :     # Declare the return variable.
1302 :     my $retVal;
1303 :     # Check the debug configuration.
1304 :     if ($FIG_Config::debug_mode) {
1305 :     $retVal = 1;
1306 :     } else {
1307 :     # Here debug mode is off, so we generate an error page.
1308 : parrello 1.9 my $pageString = PageBuilder::Build("<Html/ErrorPage.html", {}, "Html");
1309 :     print $pageString;
1310 :     }
1311 :     # Return the determination indicator.
1312 :     return $retVal;
1313 :     }
1314 :    
1315 :     =head3 Strip
1316 :    
1317 :     C<< my $string = Tracer::Strip($line); >>
1318 :    
1319 :     Strip all line terminators off a string. This is necessary when dealing with files
1320 :     that may have been transferred back and forth several times among different
1321 :     operating environments.
1322 :    
1323 :     =over 4
1324 :    
1325 :     =item line
1326 :    
1327 :     Line of text to be stripped.
1328 :    
1329 :     =item RETURN
1330 :    
1331 :     The same line of text with all the line-ending characters chopped from the end.
1332 :    
1333 :     =back
1334 :    
1335 :     =cut
1336 :    
1337 :     sub Strip {
1338 :     # Get a copy of the parameter string.
1339 :     my ($string) = @_;
1340 :     my $retVal = $string;
1341 :     # Strip the line terminator characters.
1342 :     $retVal =~ s/(\r|\n)+$//g;
1343 :     # Return the result.
1344 :     return $retVal;
1345 :     }
1346 :    
1347 :     =head3 Pad
1348 :    
1349 :     C<< my $paddedString = Tracer::Pad($string, $len, $left, $padChar); >>
1350 :    
1351 :     Pad a string to a specified length. The pad character will be a
1352 :     space, and the padding will be on the right side unless specified
1353 :     in the third parameter.
1354 :    
1355 :     =over 4
1356 :    
1357 :     =item string
1358 :    
1359 :     String to be padded.
1360 :    
1361 :     =item len
1362 :    
1363 :     Desired length of the padded string.
1364 :    
1365 :     =item left (optional)
1366 :    
1367 :     TRUE if the string is to be left-padded; otherwise it will be padded on the right.
1368 :    
1369 :     =item padChar (optional)
1370 :    
1371 :     =item RETURN
1372 :    
1373 :     Returns a copy of the original string with the spaces added to the specified end so
1374 :     that it achieves the desired length.
1375 :    
1376 :     =back
1377 :    
1378 :     =cut
1379 :    
1380 :     sub Pad {
1381 :     # Get the parameters.
1382 :     my ($string, $len, $left, $padChar) = @_;
1383 :     # Compute the padding character.
1384 :     if (! defined $padChar) {
1385 :     $padChar = " ";
1386 :     }
1387 :     # Compute the number of spaces needed.
1388 :     my $needed = $len - length $string;
1389 :     # Copy the string into the return variable.
1390 :     my $retVal = $string;
1391 :     # Only proceed if padding is needed.
1392 :     if ($needed > 0) {
1393 :     # Create the pad string.
1394 :     my $pad = $padChar x $needed;
1395 :     # Affix it to the return value.
1396 :     if ($left) {
1397 :     $retVal = $pad . $retVal;
1398 :     } else {
1399 :     $retVal .= $pad;
1400 : redwards 1.8 }
1401 : parrello 1.7 }
1402 : parrello 1.9 # Return the result.
1403 : parrello 1.7 return $retVal;
1404 :     }
1405 :    
1406 : redwards 1.8 1;

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