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 Perl::Tidy
90 version 20220217 for this purpose.
91 • Use -eos if Perl::Tidy should encode any string which it
93 decodes. This is the current default because it makes perltidy
94 behave well as a filter, and is the correct setting for most
95 programs. But do not use this setting if the calling program
96 will encode the data too, because double encoding will corrupt
97 data.
98 • Use -neos if a string should remain decoded if it was decoded
100 by Perl::Tidy. This is only appropriate if the calling program
101 will handle any needed encoding before outputting the string.
102 If needed, this flag can be added to the end of the argv
103 parameter passed to Perl::Tidy.
104 For some background information see
106 <https://github.com/perltidy/perltidy/blob/master/docs/eos_flag.md>.
107 This change in default behavior was made over a period of time as
109 follows:
110 • For versions before 20220217 the -eos flag was not available
112 and the behavior was equivalent to -neos.
113 • In version 20220217 the -eos flag was added but the default
115 remained -neos.
116 • For versions after 20220217 the default was set to -eos.
118 stderr
120 The stderr parameter allows the calling program to redirect the
121 stream that would otherwise go to the standard error output device
122 to any of the stream types listed above. This stream contains
123 important warnings and errors related to the parameters passed to
124 perltidy.
125 perltidyrc
127 If the perltidyrc file is given, it will be used instead of any
128 .perltidyrc configuration file that would otherwise be used.
129 errorfile
131 The errorfile parameter allows the calling program to capture the
132 stream that would otherwise go to either a .ERR file. This stream
133 contains warnings or errors related to the contents of one source
134 file or stream.
135 The reason that this is different from the stderr stream is that
137 when perltidy is called to process multiple files there will be up
138 to one .ERR file created for each file and it would be very
139 confusing if they were combined.
140 However if perltidy is called to process just a single perl script
142 then it may be more convenient to combine the errorfile stream with
143 the stderr stream. This can be done by setting the -se parameter,
144 in which case this parameter is ignored.
145 logfile
147 The logfile parameter allows the calling program to capture the log
148 stream. This stream is only created if requested with a -g
149 parameter. It contains detailed diagnostic information about a
150 script which may be useful for debugging.
151 teefile
153 The teefile parameter allows the calling program to capture the tee
154 stream. This stream is only created if requested with one of the
155 'tee' parameters, a --tee-pod , --tee-block-comments,
156 --tee-side-commnts, or --tee-all-comments.
157 debugfile
159 The debugfile parameter allows the calling program to capture the
160 stream produced by the --DEBUG parameter. This parameter is mainly
161 used for debugging perltidy itself.
162 argv
164 If the argv parameter is given, it will be used instead of the
165 @ARGV array. The argv parameter may be a string, a reference to a
166 string, or a reference to an array. If it is a string or reference
167 to a string, it will be parsed into an array of items just as if it
168 were a command line string.
169 dump_options
171 If the dump_options parameter is given, it must be the reference to
172 a hash. In this case, the parameters contained in any perltidyrc
173 configuration file will be placed in this hash and perltidy will
174 return immediately. This is equivalent to running perltidy with
175 --dump-options, except that the parameters are returned in a hash
176 rather than dumped to standard output. Also, by default only the
177 parameters in the perltidyrc file are returned, but this can be
178 changed (see the next parameter). This parameter provides a
179 convenient method for external programs to read a perltidyrc file.
180 An example program using this feature, perltidyrc_dump.pl, is
181 included in the distribution.
182 Any combination of the dump_ parameters may be used together.
184 dump_options_type
186 This parameter is a string which can be used to control the
187 parameters placed in the hash reference supplied by dump_options.
188 The possible values are 'perltidyrc' (default) and 'full'. The
189 'full' parameter causes both the default options plus any options
190 found in a perltidyrc file to be returned.
191 dump_getopt_flags
193 If the dump_getopt_flags parameter is given, it must be the
194 reference to a hash. This hash will receive all of the parameters
195 that perltidy understands and flags that are passed to
196 Getopt::Long. This parameter may be used alone or with the
197 dump_options flag. Perltidy will exit immediately after filling
198 this hash. See the demo program perltidyrc_dump.pl for example
199 usage.
200 dump_options_category
202 If the dump_options_category parameter is given, it must be the
203 reference to a hash. This hash will receive a hash with keys equal
204 to all long parameter names and values equal to the title of the
205 corresponding section of the perltidy manual. See the demo program
206 perltidyrc_dump.pl for example usage.
207 dump_abbreviations
209 If the dump_abbreviations parameter is given, it must be the
210 reference to a hash. This hash will receive all abbreviations used
211 by Perl::Tidy. See the demo program perltidyrc_dump.pl for example
212 usage.
213 prefilter
215 A code reference that will be applied to the source before tidying.
216 It is expected to take the full content as a string in its input,
217 and output the transformed content.
218 postfilter
220 A code reference that will be applied to the tidied result before
221 outputting. It is expected to take the full content as a string in
222 its input, and output the transformed content.
223 Note: A convenient way to check the function of your custom
225 prefilter and postfilter code is to use the --notidy option, first
226 with just the prefilter and then with both the prefilter and
227 postfilter. See also the file filter_example.pl in the perltidy
228 distribution.
229
231 An exit value of 0, 1, or 2 is returned by perltidy to indicate the
232 status of the result.
233 A exit value of 0 indicates that perltidy ran to completion with no
235 error messages.
236 An exit value of 1 indicates that the process had to be terminated
238 early due to errors in the input parameters. This can happen for
239 example if a parameter is misspelled or given an invalid value. The
240 calling program should check for this flag because if it is set the
241 destination stream will be empty or incomplete and should be ignored.
242 Error messages in the stderr stream will indicate the cause of any
243 problem.
244 An exit value of 2 indicates that perltidy ran to completion but there
246 there are warning messages in the stderr stream related to parameter
247 errors or conflicts and/or warning messages in the errorfile stream
248 relating to possible syntax errors in the source code being tidied.
249 In the event of a catastrophic error for which recovery is not possible
251 perltidy terminates by making calls to croak or confess to help the
252 programmer localize the problem. These should normally only occur
253 during program development.
254
256 Parameters which control formatting may be passed in several ways: in a
257 .perltidyrc configuration file, in the perltidyrc parameter, and in the
258 argv parameter.
259 The -syn (--check-syntax) flag may be used with all source and
261 destination streams except for standard input and output. However data
262 streams which are not associated with a filename will be copied to a
263 temporary file before being passed to Perl. This use of temporary
264 files can cause somewhat confusing output from Perl.
265 If the -pbp style is used it will typically be necessary to also
267 specify a -nst flag. This is necessary to turn off the -st flag
268 contained in the -pbp parameter set which otherwise would direct the
269 output stream to the standard output.
270
272 The following example uses string references to hold the input and
273 output code and error streams, and illustrates checking for errors.
274 use Perl::Tidy;
276 my $source_string = <<'EOT';
278 my$error=Perl::Tidy::perltidy(argv=>$argv,source=>\$source_string,
279 destination=>\$dest_string,stderr=>\$stderr_string,
280 errorfile=>\$errorfile_string,);
281 EOT
282 my $dest_string;
284 my $stderr_string;
285 my $errorfile_string;
286 my $argv = "-npro"; # Ignore any .perltidyrc at this site
287 $argv .= " -pbp"; # Format according to perl best practices
288 $argv .= " -nst"; # Must turn off -st in case -pbp is specified
289 $argv .= " -se"; # -se appends the errorfile to stderr
290 ## $argv .= " --spell-check"; # uncomment to trigger an error
291 print "<<RAW SOURCE>>\n$source_string\n";
293 my $error = Perl::Tidy::perltidy(
295 argv => $argv,
296 source => \$source_string,
297 destination => \$dest_string,
298 stderr => \$stderr_string,
299 errorfile => \$errorfile_string, # ignored when -se flag is set
300 ##phasers => 'stun', # uncomment to trigger an error
301 );
302 if ($error) {
304 # serious error in input parameters, no tidied output
306 print "<<STDERR>>\n$stderr_string\n";
307 die "Exiting because of serious errors\n";
308 }
309 if ($dest_string) { print "<<TIDIED SOURCE>>\n$dest_string\n" }
311 if ($stderr_string) { print "<<STDERR>>\n$stderr_string\n" }
312 if ($errorfile_string) { print "<<.ERR file>>\n$errorfile_string\n" }
313 Additional examples are given in examples section of the perltidy
315 distribution.
316
318 The formatter parameter is an optional callback object which allows the
319 calling program to receive tokenized lines directly from perltidy for
320 further specialized processing. When this parameter is used, the two
321 formatting options which are built into perltidy (beautification or
322 html) are ignored. The following diagram illustrates the logical flow:
323 |-- (normal route) -> code beautification
325 caller->perltidy->|-- (-html flag ) -> create html
326 |-- (formatter given)-> callback to write_line
327 This can be useful for processing perl scripts in some way. The
329 parameter $formatter in the perltidy call,
330 formatter => $formatter,
332 is an object created by the caller with a "write_line" method which
334 will accept and process tokenized lines, one line per call. Here is a
335 simple example of a "write_line" which merely prints the line number,
336 the line type (as determined by perltidy), and the text of the line:
337 sub write_line {
339 # This is called from perltidy line-by-line
341 my $self = shift;
342 my $line_of_tokens = shift;
343 my $line_type = $line_of_tokens->{_line_type};
344 my $input_line_number = $line_of_tokens->{_line_number};
345 my $input_line = $line_of_tokens->{_line_text};
346 print "$input_line_number:$line_type:$input_line";
347 }
348 The complete program, perllinetype, is contained in the examples
350 section of the source distribution. As this example shows, the
351 callback method receives a parameter $line_of_tokens, which is a
352 reference to a hash of other useful information. This example uses
353 these hash entries:
354 $line_of_tokens->{_line_number} - the line number (1,2,...)
356 $line_of_tokens->{_line_text} - the text of the line
357 $line_of_tokens->{_line_type} - the type of the line, one of:
358 SYSTEM - system-specific code before hash-bang line
360 CODE - line of perl code (including comments)
361 POD_START - line starting pod, such as '=head'
362 POD - pod documentation text
363 POD_END - last line of pod section, '=cut'
364 HERE - text of here-document
365 HERE_END - last line of here-doc (target word)
366 FORMAT - format section
367 FORMAT_END - last line of format section, '.'
368 DATA_START - __DATA__ line
369 DATA - unidentified text following __DATA__
370 END_START - __END__ line
371 END - unidentified text following __END__
372 ERROR - we are in big trouble, probably not a perl script
373 Most applications will be only interested in lines of type CODE. For
375 another example, let's write a program which checks for one of the so-
376 called naughty matching variables "&`", $&, and "$'", which can slow
377 down processing. Here is a write_line, from the example program
378 find_naughty.pl, which does that:
379 sub write_line {
381 # This is called back from perltidy line-by-line
383 # We're looking for $`, $&, and $'
384 my ( $self, $line_of_tokens ) = @_;
385 # pull out some stuff we might need
387 my $line_type = $line_of_tokens->{_line_type};
388 my $input_line_number = $line_of_tokens->{_line_number};
389 my $input_line = $line_of_tokens->{_line_text};
390 my $rtoken_type = $line_of_tokens->{_rtoken_type};
391 my $rtokens = $line_of_tokens->{_rtokens};
392 chomp $input_line;
393 # skip comments, pod, etc
395 return if ( $line_type ne 'CODE' );
396 # loop over tokens looking for $`, $&, and $'
398 for ( my $j = 0 ; $j < @$rtoken_type ; $j++ ) {
399 # we only want to examine token types 'i' (identifier)
401 next unless $$rtoken_type[$j] eq 'i';
402 # pull out the actual token text
404 my $token = $$rtokens[$j];
405 # and check it
407 if ( $token =~ /^\$[\`\&\']$/ ) {
408 print STDERR
409 "$input_line_number: $token\n";
410 }
411 }
412 }
413 This example pulls out these tokenization variables from the
415 $line_of_tokens hash reference:
416 $rtoken_type = $line_of_tokens->{_rtoken_type};
418 $rtokens = $line_of_tokens->{_rtokens};
419 The variable $rtoken_type is a reference to an array of token type
421 codes, and $rtokens is a reference to a corresponding array of token
422 text. These are obviously only defined for lines of type CODE.
423 Perltidy classifies tokens into types, and has a brief code for each
424 type. You can get a complete list at any time by running perltidy from
425 the command line with
426 perltidy --dump-token-types
428 In the present example, we are only looking for tokens of type i
430 (identifiers), so the for loop skips past all other types. When an
431 identifier is found, its actual text is checked to see if it is one
432 being sought. If so, the above write_line prints the token and its
433 line number.
434 The examples section of the source distribution has some examples of
436 programs which use the formatter option.
437 For help with perltidy's peculiar way of breaking lines into tokens,
439 you might run, from the command line,
440 perltidy -D filename
442 where filename is a short script of interest. This will produce
444 filename.DEBUG with interleaved lines of text and their token types.
445 The -D flag has been in perltidy from the beginning for this purpose.
446 If you want to see the code which creates this file, it is "sub
447 Perl::Tidy::Debugger::write_debug_entry"
448
450 &perltidy
451
453 The module 'Perl::Tidy' comes with a binary 'perltidy' which is
454 installed when the module is installed. The module name is case-
455 sensitive. For example, the basic command for installing with cpanm is
456 'cpanm Perl::Tidy'.
457
459 This man page documents Perl::Tidy version 20220613
460
462 This package is free software; you can redistribute it and/or modify it
463 under the terms of the "GNU General Public License".
464 Please refer to the file "COPYING" for details.
466
468 The source code repository is at
469 <https://github.com/perltidy/perltidy>.
470 To report a new bug or problem, use the "issues" link on this page.
472
474 The perltidy(1) man page describes all of the features of perltidy. It
475 can be found at http://perltidy.sourceforge.net.
476perl v5.36.0 2022-07-22 Perl::Tidy(3)