1Perl::Tidy(3) User Contributed Perl Documentation Perl::Tidy(3)
2
6 Perl::Tidy - Parses and beautifies perl source
7
9 use Perl::Tidy;
10 my $error_flag = Perl::Tidy::perltidy(
12 source => $source,
13 destination => $destination,
14 stderr => $stderr,
15 argv => $argv,
16 perltidyrc => $perltidyrc,
17 logfile => $logfile,
18 errorfile => $errorfile,
19 teefile => $teefile,
20 debugfile => $debugfile,
21 formatter => $formatter, # callback object (see below)
22 dump_options => $dump_options,
23 dump_options_type => $dump_options_type,
24 prefilter => $prefilter_coderef,
25 postfilter => $postfilter_coderef,
26 );
27
29 This module makes the functionality of the perltidy utility available
30 to perl scripts. Any or all of the input parameters may be omitted, in
31 which case the @ARGV array will be used to provide input parameters as
32 described in the perltidy(1) man page.
33 For example, the perltidy script is basically just this:
35 use Perl::Tidy;
37 Perl::Tidy::perltidy();
38 The call to perltidy returns a scalar $error_flag which is TRUE if an
40 error caused premature termination, and FALSE if the process ran to
41 normal completion. Additional discuss of errors is contained below in
42 the ERROR HANDLING section.
43 The module accepts input and output streams by a variety of methods.
45 The following list of parameters may be any of the following: a
46 filename, an ARRAY reference, a SCALAR reference, or an object with
47 either a getline or print method, as appropriate.
48 source - the source of the script to be formatted
50 destination - the destination of the formatted output
51 stderr - standard error output
52 perltidyrc - the .perltidyrc file
53 logfile - the .LOG file stream, if any
54 errorfile - the .ERR file stream, if any
55 dump_options - ref to a hash to receive parameters (see below),
56 dump_options_type - controls contents of dump_options
57 dump_getopt_flags - ref to a hash to receive Getopt flags
58 dump_options_category - ref to a hash giving category of options
59 dump_abbreviations - ref to a hash giving all abbreviations
60 The following chart illustrates the logic used to decide how to treat a
62 parameter.
63 ref($param) $param is assumed to be:
65 ----------- ---------------------
66 undef a filename
67 SCALAR ref to string
68 ARRAY ref to array
69 (other) object with getline (if source) or print method
70 If the parameter is an object, and the object has a close method, that
72 close method will be called at the end of the stream.
73 source
75 If the source parameter is given, it defines the source of the
76 input stream. If an input stream is defined with the source
77 parameter then no other source filenames may be specified in the
78 @ARGV array or argv parameter.
79 destination
81 If the destination parameter is given, it will be used to define
82 the file or memory location to receive output of perltidy.
83 stderr
85 The stderr parameter allows the calling program to redirect the
86 stream that would otherwise go to the standard error output device
87 to any of the stream types listed above. This stream contains
88 important warnings and errors related to the parameters passed to
89 perltidy.
90 perltidyrc
92 If the perltidyrc file is given, it will be used instead of any
93 .perltidyrc configuration file that would otherwise be used.
94 errorfile
96 The errorfile parameter allows the calling program to capture the
97 stream that would otherwise go to either a .ERR file. This stream
98 contains warnings or errors related to the contents of one source
99 file or stream.
100 The reason that this is different from the stderr stream is that
102 when perltidy is called to process multiple files there will be up
103 to one .ERR file created for each file and it would be very
104 confusing if they were combined.
105 However if perltidy is called to process just a single perl script
107 then it may be more convenient to combine the errorfile stream with
108 the stderr stream. This can be done by setting the -se parameter,
109 in which case this parameter is ignored.
110 logfile
112 The logfile parameter allows the calling program to capture the log
113 stream. This stream is only created if requested with a -g
114 parameter. It contains detailed diagnostic information about a
115 script which may be useful for debugging.
116 teefile
118 The teefile parameter allows the calling program to capture the tee
119 stream. This stream is only created if requested with one of the
120 'tee' parameters, a --tee-pod , --tee-block-comments,
121 --tee-side-commnts, or --tee-all-comments.
122 debugfile
124 The debugfile parameter allows the calling program to capture the
125 stream produced by the --DEBUG parameter. This parameter is mainly
126 used for debugging perltidy itself.
127 argv
129 If the argv parameter is given, it will be used instead of the
130 @ARGV array. The argv parameter may be a string, a reference to a
131 string, or a reference to an array. If it is a string or reference
132 to a string, it will be parsed into an array of items just as if it
133 were a command line string.
134 dump_options
136 If the dump_options parameter is given, it must be the reference to
137 a hash. In this case, the parameters contained in any perltidyrc
138 configuration file will be placed in this hash and perltidy will
139 return immediately. This is equivalent to running perltidy with
140 --dump-options, except that the parameters are returned in a hash
141 rather than dumped to standard output. Also, by default only the
142 parameters in the perltidyrc file are returned, but this can be
143 changed (see the next parameter). This parameter provides a
144 convenient method for external programs to read a perltidyrc file.
145 An example program using this feature, perltidyrc_dump.pl, is
146 included in the distribution.
147 Any combination of the dump_ parameters may be used together.
149 dump_options_type
151 This parameter is a string which can be used to control the
152 parameters placed in the hash reference supplied by dump_options.
153 The possible values are 'perltidyrc' (default) and 'full'. The
154 'full' parameter causes both the default options plus any options
155 found in a perltidyrc file to be returned.
156 dump_getopt_flags
158 If the dump_getopt_flags parameter is given, it must be the
159 reference to a hash. This hash will receive all of the parameters
160 that perltidy understands and flags that are passed to
161 Getopt::Long. This parameter may be used alone or with the
162 dump_options flag. Perltidy will exit immediately after filling
163 this hash. See the demo program perltidyrc_dump.pl for example
164 usage.
165 dump_options_category
167 If the dump_options_category parameter is given, it must be the
168 reference to a hash. This hash will receive a hash with keys equal
169 to all long parameter names and values equal to the title of the
170 corresponding section of the perltidy manual. See the demo program
171 perltidyrc_dump.pl for example usage.
172 dump_abbreviations
174 If the dump_abbreviations parameter is given, it must be the
175 reference to a hash. This hash will receive all abbreviations used
176 by Perl::Tidy. See the demo program perltidyrc_dump.pl for example
177 usage.
178 prefilter
180 A code reference that will be applied to the source before tidying.
181 It is expected to take the full content as a string in its input,
182 and output the transformed content.
183 postfilter
185 A code reference that will be applied to the tidied result before
186 outputting. It is expected to take the full content as a string in
187 its input, and output the transformed content.
188 Note: A convenient way to check the function of your custom
190 prefilter and postfilter code is to use the --notidy option, first
191 with just the prefilter and then with both the prefilter and
192 postfilter. See also the file filter_example.pl in the perltidy
193 distribution.
194
196 An exit value of 0, 1, or 2 is returned by perltidy to indicate the
197 status of the result.
198 A exit value of 0 indicates that perltidy ran to completion with no
200 error messages.
201 An exit value of 1 indicates that the process had to be terminated
203 early due to errors in the input parameters. This can happen for
204 example if a parameter is misspelled or given an invalid value. The
205 calling program should check for this flag because if it is set the
206 destination stream will be empty or incomplete and should be ignored.
207 Error messages in the stderr stream will indicate the cause of any
208 problem.
209 An exit value of 2 indicates that perltidy ran to completion but there
211 there are warning messages in the stderr stream related to parameter
212 errors or conflicts and/or warning messages in the errorfile stream
213 relating to possible syntax errors in the source code being tidied.
214 In the event of a catastrophic error for which recovery is not possible
216 perltidy terminates by making calls to croak or confess to help the
217 programmer localize the problem. These should normally only occur
218 during program development.
219
221 Parameters which control formatting may be passed in several ways: in a
222 .perltidyrc configuration file, in the perltidyrc parameter, and in the
223 argv parameter.
224 The -syn (--check-syntax) flag may be used with all source and
226 destination streams except for standard input and output. However data
227 streams which are not associated with a filename will be copied to a
228 temporary file before being passed to Perl. This use of temporary
229 files can cause somewhat confusing output from Perl.
230 If the -pbp style is used it will typically be necessary to also
232 specify a -nst flag. This is necessary to turn off the -st flag
233 contained in the -pbp parameter set which otherwise would direct the
234 output stream to the standard output.
235
237 The following example uses string references to hold the input and
238 output code and error streams, and illustrates checking for errors.
239 use Perl::Tidy;
241 my $source_string = <<'EOT';
243 my$error=Perl::Tidy::perltidy(argv=>$argv,source=>\$source_string,
244 destination=>\$dest_string,stderr=>\$stderr_string,
245 errorfile=>\$errorfile_string,);
246 EOT
247 my $dest_string;
249 my $stderr_string;
250 my $errorfile_string;
251 my $argv = "-npro"; # Ignore any .perltidyrc at this site
252 $argv .= " -pbp"; # Format according to perl best practices
253 $argv .= " -nst"; # Must turn off -st in case -pbp is specified
254 $argv .= " -se"; # -se appends the errorfile to stderr
255 ## $argv .= " --spell-check"; # uncomment to trigger an error
256 print "<<RAW SOURCE>>\n$source_string\n";
258 my $error = Perl::Tidy::perltidy(
260 argv => $argv,
261 source => \$source_string,
262 destination => \$dest_string,
263 stderr => \$stderr_string,
264 errorfile => \$errorfile_string, # ignored when -se flag is set
265 ##phasers => 'stun', # uncomment to trigger an error
266 );
267 if ($error) {
269 # serious error in input parameters, no tidied output
271 print "<<STDERR>>\n$stderr_string\n";
272 die "Exiting because of serious errors\n";
273 }
274 if ($dest_string) { print "<<TIDIED SOURCE>>\n$dest_string\n" }
276 if ($stderr_string) { print "<<STDERR>>\n$stderr_string\n" }
277 if ($errorfile_string) { print "<<.ERR file>>\n$errorfile_string\n" }
278 Additional examples are given in examples section of the perltidy
280 distribution.
281
283 The formatter parameter is an optional callback object which allows the
284 calling program to receive tokenized lines directly from perltidy for
285 further specialized processing. When this parameter is used, the two
286 formatting options which are built into perltidy (beautification or
287 html) are ignored. The following diagram illustrates the logical flow:
288 |-- (normal route) -> code beautification
290 caller->perltidy->|-- (-html flag ) -> create html
291 |-- (formatter given)-> callback to write_line
292 This can be useful for processing perl scripts in some way. The
294 parameter $formatter in the perltidy call,
295 formatter => $formatter,
297 is an object created by the caller with a "write_line" method which
299 will accept and process tokenized lines, one line per call. Here is a
300 simple example of a "write_line" which merely prints the line number,
301 the line type (as determined by perltidy), and the text of the line:
302 sub write_line {
304 # This is called from perltidy line-by-line
306 my $self = shift;
307 my $line_of_tokens = shift;
308 my $line_type = $line_of_tokens->{_line_type};
309 my $input_line_number = $line_of_tokens->{_line_number};
310 my $input_line = $line_of_tokens->{_line_text};
311 print "$input_line_number:$line_type:$input_line";
312 }
313 The complete program, perllinetype, is contained in the examples
315 section of the source distribution. As this example shows, the
316 callback method receives a parameter $line_of_tokens, which is a
317 reference to a hash of other useful information. This example uses
318 these hash entries:
319 $line_of_tokens->{_line_number} - the line number (1,2,...)
321 $line_of_tokens->{_line_text} - the text of the line
322 $line_of_tokens->{_line_type} - the type of the line, one of:
323 SYSTEM - system-specific code before hash-bang line
325 CODE - line of perl code (including comments)
326 POD_START - line starting pod, such as '=head'
327 POD - pod documentation text
328 POD_END - last line of pod section, '=cut'
329 HERE - text of here-document
330 HERE_END - last line of here-doc (target word)
331 FORMAT - format section
332 FORMAT_END - last line of format section, '.'
333 DATA_START - __DATA__ line
334 DATA - unidentified text following __DATA__
335 END_START - __END__ line
336 END - unidentified text following __END__
337 ERROR - we are in big trouble, probably not a perl script
338 Most applications will be only interested in lines of type CODE. For
340 another example, let's write a program which checks for one of the so-
341 called naughty matching variables "&`", $&, and "$'", which can slow
342 down processing. Here is a write_line, from the example program
343 find_naughty.pl, which does that:
344 sub write_line {
346 # This is called back from perltidy line-by-line
348 # We're looking for $`, $&, and $'
349 my ( $self, $line_of_tokens ) = @_;
350 # pull out some stuff we might need
352 my $line_type = $line_of_tokens->{_line_type};
353 my $input_line_number = $line_of_tokens->{_line_number};
354 my $input_line = $line_of_tokens->{_line_text};
355 my $rtoken_type = $line_of_tokens->{_rtoken_type};
356 my $rtokens = $line_of_tokens->{_rtokens};
357 chomp $input_line;
358 # skip comments, pod, etc
360 return if ( $line_type ne 'CODE' );
361 # loop over tokens looking for $`, $&, and $'
363 for ( my $j = 0 ; $j < @$rtoken_type ; $j++ ) {
364 # we only want to examine token types 'i' (identifier)
366 next unless $$rtoken_type[$j] eq 'i';
367 # pull out the actual token text
369 my $token = $$rtokens[$j];
370 # and check it
372 if ( $token =~ /^\$[\`\&\']$/ ) {
373 print STDERR
374 "$input_line_number: $token\n";
375 }
376 }
377 }
378 This example pulls out these tokenization variables from the
380 $line_of_tokens hash reference:
381 $rtoken_type = $line_of_tokens->{_rtoken_type};
383 $rtokens = $line_of_tokens->{_rtokens};
384 The variable $rtoken_type is a reference to an array of token type
386 codes, and $rtokens is a reference to a corresponding array of token
387 text. These are obviously only defined for lines of type CODE.
388 Perltidy classifies tokens into types, and has a brief code for each
389 type. You can get a complete list at any time by running perltidy from
390 the command line with
391 perltidy --dump-token-types
393 In the present example, we are only looking for tokens of type i
395 (identifiers), so the for loop skips past all other types. When an
396 identifier is found, its actual text is checked to see if it is one
397 being sought. If so, the above write_line prints the token and its
398 line number.
399 The formatter feature is relatively new in perltidy, and further
401 documentation needs to be written to complete its description.
402 However, several example programs have been written and can be found in
403 the examples section of the source distribution. Probably the best way
404 to get started is to find one of the examples which most closely
405 matches your application and start modifying it.
406 For help with perltidy's peculiar way of breaking lines into tokens,
408 you might run, from the command line,
409 perltidy -D filename
411 where filename is a short script of interest. This will produce
413 filename.DEBUG with interleaved lines of text and their token types.
414 The -D flag has been in perltidy from the beginning for this purpose.
415 If you want to see the code which creates this file, it is
416 "write_debug_entry" in Tidy.pm.
417
419 &perltidy
420
422 The module 'Perl::Tidy' comes with a binary 'perltidy' which is
423 installed when the module is installed. The module name is case-
424 sensitive. For example, the basic command for installing with cpanm is
425 'cpanm Perl::Tidy'.
426
428 This man page documents Perl::Tidy version 20210402
429
431 This package is free software; you can redistribute it and/or modify it
432 under the terms of the "GNU General Public License".
433 Please refer to the file "COPYING" for details.
435
437 A list of current bugs and issues can be found at the CPAN site
438 <https://rt.cpan.org/Public/Dist/Display.html?Name=Perl-Tidy>
439 To report a new bug or problem, use the link on this page.
441 The source code repository is at
443 <https://github.com/perltidy/perltidy>.
444
446 The perltidy(1) man page describes all of the features of perltidy. It
447 can be found at http://perltidy.sourceforge.net.
448perl v5.32.1 2021-04-01 Perl::Tidy(3)