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 Important note if destination is a string or array reference. Perl
85 strings of characters which are decoded as utf8 by Perl::Tidy can
86 be returned in either of two possible states, decoded or encoded,
87 and it is important that the calling program and Perl::Tidy are in
88 agreement regarding the state to be returned. A flag
89 --encode-output-strings, or simply -eos, was added in versions of
90 Perl::Tidy after 20220101 for this purpose. This flag should be
91 added to the end of the argv paremeter (described below) if
92 Perl::Tidy will be decoding utf8 text. The options are as follows.
93 • Use -eos if Perl::Tidy should encode any string which it
95 decodes. This is probably most convenient for most programs.
96 But do not use this setting if the calling program will encode
97 the data too, because double encoding will corrupt data.
98 • Use -neos if a string should remain decoded if it was decoded
100 by Perl::Tidy. This is appropriate if the calling program will
101 handle any needed encoding before outputting the string.
102 • The current default is -neos, but the default could change in a
104 future version, so -neos should still be set, if appropriate,
105 to allow for the possibility of a future change in the default.
106 For example, to set -eos the following could be used
108 $argv .= " -eos" if ( $Perl::Tidy::VERSION > 20220101 );
110 $error_flag = Perl::Tidy::perltidy(
112 argv => $argv,
113 source => \$source,
114 destination => \$destination,
115 stderr => \$stderr,
116 errorfile => \$errorfile
117 );
118 The test on version allows older versions of Perl::Tidy to still be
120 used.
121 For some background information see
123 <https://github.com/perltidy/perltidy/issues/83> and
124 <https://github.com/houseabsolute/perl-code-tidyall/issues/84>.
125 stderr
127 The stderr parameter allows the calling program to redirect the
128 stream that would otherwise go to the standard error output device
129 to any of the stream types listed above. This stream contains
130 important warnings and errors related to the parameters passed to
131 perltidy.
132 perltidyrc
134 If the perltidyrc file is given, it will be used instead of any
135 .perltidyrc configuration file that would otherwise be used.
136 errorfile
138 The errorfile parameter allows the calling program to capture the
139 stream that would otherwise go to either a .ERR file. This stream
140 contains warnings or errors related to the contents of one source
141 file or stream.
142 The reason that this is different from the stderr stream is that
144 when perltidy is called to process multiple files there will be up
145 to one .ERR file created for each file and it would be very
146 confusing if they were combined.
147 However if perltidy is called to process just a single perl script
149 then it may be more convenient to combine the errorfile stream with
150 the stderr stream. This can be done by setting the -se parameter,
151 in which case this parameter is ignored.
152 logfile
154 The logfile parameter allows the calling program to capture the log
155 stream. This stream is only created if requested with a -g
156 parameter. It contains detailed diagnostic information about a
157 script which may be useful for debugging.
158 teefile
160 The teefile parameter allows the calling program to capture the tee
161 stream. This stream is only created if requested with one of the
162 'tee' parameters, a --tee-pod , --tee-block-comments,
163 --tee-side-commnts, or --tee-all-comments.
164 debugfile
166 The debugfile parameter allows the calling program to capture the
167 stream produced by the --DEBUG parameter. This parameter is mainly
168 used for debugging perltidy itself.
169 argv
171 If the argv parameter is given, it will be used instead of the
172 @ARGV array. The argv parameter may be a string, a reference to a
173 string, or a reference to an array. If it is a string or reference
174 to a string, it will be parsed into an array of items just as if it
175 were a command line string.
176 dump_options
178 If the dump_options parameter is given, it must be the reference to
179 a hash. In this case, the parameters contained in any perltidyrc
180 configuration file will be placed in this hash and perltidy will
181 return immediately. This is equivalent to running perltidy with
182 --dump-options, except that the parameters are returned in a hash
183 rather than dumped to standard output. Also, by default only the
184 parameters in the perltidyrc file are returned, but this can be
185 changed (see the next parameter). This parameter provides a
186 convenient method for external programs to read a perltidyrc file.
187 An example program using this feature, perltidyrc_dump.pl, is
188 included in the distribution.
189 Any combination of the dump_ parameters may be used together.
191 dump_options_type
193 This parameter is a string which can be used to control the
194 parameters placed in the hash reference supplied by dump_options.
195 The possible values are 'perltidyrc' (default) and 'full'. The
196 'full' parameter causes both the default options plus any options
197 found in a perltidyrc file to be returned.
198 dump_getopt_flags
200 If the dump_getopt_flags parameter is given, it must be the
201 reference to a hash. This hash will receive all of the parameters
202 that perltidy understands and flags that are passed to
203 Getopt::Long. This parameter may be used alone or with the
204 dump_options flag. Perltidy will exit immediately after filling
205 this hash. See the demo program perltidyrc_dump.pl for example
206 usage.
207 dump_options_category
209 If the dump_options_category parameter is given, it must be the
210 reference to a hash. This hash will receive a hash with keys equal
211 to all long parameter names and values equal to the title of the
212 corresponding section of the perltidy manual. See the demo program
213 perltidyrc_dump.pl for example usage.
214 dump_abbreviations
216 If the dump_abbreviations parameter is given, it must be the
217 reference to a hash. This hash will receive all abbreviations used
218 by Perl::Tidy. See the demo program perltidyrc_dump.pl for example
219 usage.
220 prefilter
222 A code reference that will be applied to the source before tidying.
223 It is expected to take the full content as a string in its input,
224 and output the transformed content.
225 postfilter
227 A code reference that will be applied to the tidied result before
228 outputting. It is expected to take the full content as a string in
229 its input, and output the transformed content.
230 Note: A convenient way to check the function of your custom
232 prefilter and postfilter code is to use the --notidy option, first
233 with just the prefilter and then with both the prefilter and
234 postfilter. See also the file filter_example.pl in the perltidy
235 distribution.
236
238 An exit value of 0, 1, or 2 is returned by perltidy to indicate the
239 status of the result.
240 A exit value of 0 indicates that perltidy ran to completion with no
242 error messages.
243 An exit value of 1 indicates that the process had to be terminated
245 early due to errors in the input parameters. This can happen for
246 example if a parameter is misspelled or given an invalid value. The
247 calling program should check for this flag because if it is set the
248 destination stream will be empty or incomplete and should be ignored.
249 Error messages in the stderr stream will indicate the cause of any
250 problem.
251 An exit value of 2 indicates that perltidy ran to completion but there
253 there are warning messages in the stderr stream related to parameter
254 errors or conflicts and/or warning messages in the errorfile stream
255 relating to possible syntax errors in the source code being tidied.
256 In the event of a catastrophic error for which recovery is not possible
258 perltidy terminates by making calls to croak or confess to help the
259 programmer localize the problem. These should normally only occur
260 during program development.
261
263 Parameters which control formatting may be passed in several ways: in a
264 .perltidyrc configuration file, in the perltidyrc parameter, and in the
265 argv parameter.
266 The -syn (--check-syntax) flag may be used with all source and
268 destination streams except for standard input and output. However data
269 streams which are not associated with a filename will be copied to a
270 temporary file before being passed to Perl. This use of temporary
271 files can cause somewhat confusing output from Perl.
272 If the -pbp style is used it will typically be necessary to also
274 specify a -nst flag. This is necessary to turn off the -st flag
275 contained in the -pbp parameter set which otherwise would direct the
276 output stream to the standard output.
277
279 The following example uses string references to hold the input and
280 output code and error streams, and illustrates checking for errors.
281 use Perl::Tidy;
283 my $source_string = <<'EOT';
285 my$error=Perl::Tidy::perltidy(argv=>$argv,source=>\$source_string,
286 destination=>\$dest_string,stderr=>\$stderr_string,
287 errorfile=>\$errorfile_string,);
288 EOT
289 my $dest_string;
291 my $stderr_string;
292 my $errorfile_string;
293 my $argv = "-npro"; # Ignore any .perltidyrc at this site
294 $argv .= " -pbp"; # Format according to perl best practices
295 $argv .= " -nst"; # Must turn off -st in case -pbp is specified
296 $argv .= " -se"; # -se appends the errorfile to stderr
297 ## $argv .= " --spell-check"; # uncomment to trigger an error
298 print "<<RAW SOURCE>>\n$source_string\n";
300 my $error = Perl::Tidy::perltidy(
302 argv => $argv,
303 source => \$source_string,
304 destination => \$dest_string,
305 stderr => \$stderr_string,
306 errorfile => \$errorfile_string, # ignored when -se flag is set
307 ##phasers => 'stun', # uncomment to trigger an error
308 );
309 if ($error) {
311 # serious error in input parameters, no tidied output
313 print "<<STDERR>>\n$stderr_string\n";
314 die "Exiting because of serious errors\n";
315 }
316 if ($dest_string) { print "<<TIDIED SOURCE>>\n$dest_string\n" }
318 if ($stderr_string) { print "<<STDERR>>\n$stderr_string\n" }
319 if ($errorfile_string) { print "<<.ERR file>>\n$errorfile_string\n" }
320 Additional examples are given in examples section of the perltidy
322 distribution.
323
325 The formatter parameter is an optional callback object which allows the
326 calling program to receive tokenized lines directly from perltidy for
327 further specialized processing. When this parameter is used, the two
328 formatting options which are built into perltidy (beautification or
329 html) are ignored. The following diagram illustrates the logical flow:
330 |-- (normal route) -> code beautification
332 caller->perltidy->|-- (-html flag ) -> create html
333 |-- (formatter given)-> callback to write_line
334 This can be useful for processing perl scripts in some way. The
336 parameter $formatter in the perltidy call,
337 formatter => $formatter,
339 is an object created by the caller with a "write_line" method which
341 will accept and process tokenized lines, one line per call. Here is a
342 simple example of a "write_line" which merely prints the line number,
343 the line type (as determined by perltidy), and the text of the line:
344 sub write_line {
346 # This is called from perltidy line-by-line
348 my $self = shift;
349 my $line_of_tokens = shift;
350 my $line_type = $line_of_tokens->{_line_type};
351 my $input_line_number = $line_of_tokens->{_line_number};
352 my $input_line = $line_of_tokens->{_line_text};
353 print "$input_line_number:$line_type:$input_line";
354 }
355 The complete program, perllinetype, is contained in the examples
357 section of the source distribution. As this example shows, the
358 callback method receives a parameter $line_of_tokens, which is a
359 reference to a hash of other useful information. This example uses
360 these hash entries:
361 $line_of_tokens->{_line_number} - the line number (1,2,...)
363 $line_of_tokens->{_line_text} - the text of the line
364 $line_of_tokens->{_line_type} - the type of the line, one of:
365 SYSTEM - system-specific code before hash-bang line
367 CODE - line of perl code (including comments)
368 POD_START - line starting pod, such as '=head'
369 POD - pod documentation text
370 POD_END - last line of pod section, '=cut'
371 HERE - text of here-document
372 HERE_END - last line of here-doc (target word)
373 FORMAT - format section
374 FORMAT_END - last line of format section, '.'
375 DATA_START - __DATA__ line
376 DATA - unidentified text following __DATA__
377 END_START - __END__ line
378 END - unidentified text following __END__
379 ERROR - we are in big trouble, probably not a perl script
380 Most applications will be only interested in lines of type CODE. For
382 another example, let's write a program which checks for one of the so-
383 called naughty matching variables "&`", $&, and "$'", which can slow
384 down processing. Here is a write_line, from the example program
385 find_naughty.pl, which does that:
386 sub write_line {
388 # This is called back from perltidy line-by-line
390 # We're looking for $`, $&, and $'
391 my ( $self, $line_of_tokens ) = @_;
392 # pull out some stuff we might need
394 my $line_type = $line_of_tokens->{_line_type};
395 my $input_line_number = $line_of_tokens->{_line_number};
396 my $input_line = $line_of_tokens->{_line_text};
397 my $rtoken_type = $line_of_tokens->{_rtoken_type};
398 my $rtokens = $line_of_tokens->{_rtokens};
399 chomp $input_line;
400 # skip comments, pod, etc
402 return if ( $line_type ne 'CODE' );
403 # loop over tokens looking for $`, $&, and $'
405 for ( my $j = 0 ; $j < @$rtoken_type ; $j++ ) {
406 # we only want to examine token types 'i' (identifier)
408 next unless $$rtoken_type[$j] eq 'i';
409 # pull out the actual token text
411 my $token = $$rtokens[$j];
412 # and check it
414 if ( $token =~ /^\$[\`\&\']$/ ) {
415 print STDERR
416 "$input_line_number: $token\n";
417 }
418 }
419 }
420 This example pulls out these tokenization variables from the
422 $line_of_tokens hash reference:
423 $rtoken_type = $line_of_tokens->{_rtoken_type};
425 $rtokens = $line_of_tokens->{_rtokens};
426 The variable $rtoken_type is a reference to an array of token type
428 codes, and $rtokens is a reference to a corresponding array of token
429 text. These are obviously only defined for lines of type CODE.
430 Perltidy classifies tokens into types, and has a brief code for each
431 type. You can get a complete list at any time by running perltidy from
432 the command line with
433 perltidy --dump-token-types
435 In the present example, we are only looking for tokens of type i
437 (identifiers), so the for loop skips past all other types. When an
438 identifier is found, its actual text is checked to see if it is one
439 being sought. If so, the above write_line prints the token and its
440 line number.
441 The formatter feature is relatively new in perltidy, and further
443 documentation needs to be written to complete its description.
444 However, several example programs have been written and can be found in
445 the examples section of the source distribution. Probably the best way
446 to get started is to find one of the examples which most closely
447 matches your application and start modifying it.
448 For help with perltidy's peculiar way of breaking lines into tokens,
450 you might run, from the command line,
451 perltidy -D filename
453 where filename is a short script of interest. This will produce
455 filename.DEBUG with interleaved lines of text and their token types.
456 The -D flag has been in perltidy from the beginning for this purpose.
457 If you want to see the code which creates this file, it is
458 "write_debug_entry" in Tidy.pm.
459
461 &perltidy
462
464 The module 'Perl::Tidy' comes with a binary 'perltidy' which is
465 installed when the module is installed. The module name is case-
466 sensitive. For example, the basic command for installing with cpanm is
467 'cpanm Perl::Tidy'.
468
470 This man page documents Perl::Tidy version 20220217
471
473 This package is free software; you can redistribute it and/or modify it
474 under the terms of the "GNU General Public License".
475 Please refer to the file "COPYING" for details.
477
479 A list of current bugs and issues can be found at the CPAN site
480 <https://rt.cpan.org/Public/Dist/Display.html?Name=Perl-Tidy>
481 To report a new bug or problem, use the link on this page.
483 The source code repository is at
485 <https://github.com/perltidy/perltidy>.
486
488 The perltidy(1) man page describes all of the features of perltidy. It
489 can be found at http://perltidy.sourceforge.net.
490perl v5.34.0 2022-02-15 Perl::Tidy(3)