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 formatter => $formatter, # callback object (see below)
20 dump_options => $dump_options,
21 dump_options_type => $dump_options_type,
22 prefilter => $prefilter_coderef,
23 postfilter => $postfilter_coderef,
24 );
25
27 This module makes the functionality of the perltidy utility available
28 to perl scripts. Any or all of the input parameters may be omitted, in
29 which case the @ARGV array will be used to provide input parameters as
30 described in the perltidy(1) man page.
31 For example, the perltidy script is basically just this:
33 use Perl::Tidy;
35 Perl::Tidy::perltidy();
36 The call to perltidy returns a scalar $error_flag which is TRUE if an
38 error caused premature termination, and FALSE if the process ran to
39 normal completion. Additional discuss of errors is contained below in
40 the ERROR HANDLING section.
41 The module accepts input and output streams by a variety of methods.
43 The following list of parameters may be any of the following: a
44 filename, an ARRAY reference, a SCALAR reference, or an object with
45 either a getline or print method, as appropriate.
46 source - the source of the script to be formatted
48 destination - the destination of the formatted output
49 stderr - standard error output
50 perltidyrc - the .perltidyrc file
51 logfile - the .LOG file stream, if any
52 errorfile - the .ERR file stream, if any
53 dump_options - ref to a hash to receive parameters (see below),
54 dump_options_type - controls contents of dump_options
55 dump_getopt_flags - ref to a hash to receive Getopt flags
56 dump_options_category - ref to a hash giving category of options
57 dump_abbreviations - ref to a hash giving all abbreviations
58 The following chart illustrates the logic used to decide how to treat a
60 parameter.
61 ref($param) $param is assumed to be:
63 ----------- ---------------------
64 undef a filename
65 SCALAR ref to string
66 ARRAY ref to array
67 (other) object with getline (if source) or print method
68 If the parameter is an object, and the object has a close method, that
70 close method will be called at the end of the stream.
71 source
73 If the source parameter is given, it defines the source of the
74 input stream. If an input stream is defined with the source
75 parameter then no other source filenames may be specified in the
76 @ARGV array or argv parameter.
77 destination
79 If the destination parameter is given, it will be used to define
80 the file or memory location to receive output of perltidy.
81 stderr
83 The stderr parameter allows the calling program to redirect the
84 stream that would otherwise go to the standard error output device
85 to any of the stream types listed above. This stream contains
86 important warnings and errors related to the parameters passed to
87 perltidy.
88 perltidyrc
90 If the perltidyrc file is given, it will be used instead of any
91 .perltidyrc configuration file that would otherwise be used.
92 errorfile
94 The errorfile parameter allows the calling program to capture the
95 stream that would otherwise go to either a .ERR file. This stream
96 contains warnings or errors related to the contents of one source
97 file or stream.
98 The reason that this is different from the stderr stream is that
100 when perltidy is called to process multiple files there will be up
101 to one .ERR file created for each file and it would be very
102 confusing if they were combined.
103 However if perltidy is called to process just a single perl script
105 then it may be more convenient to combine the errorfile stream with
106 the stderr stream. This can be done by setting the -se parameter,
107 in which case this parameter is ignored.
108 logfile
110 The logfile parameter allows the calling program to capture the log
111 stream. This stream is only created if requested with a -g
112 parameter. It contains detailed diagnostic information about a
113 script which may be useful for debugging.
114 argv
116 If the argv parameter is given, it will be used instead of the
117 @ARGV array. The argv parameter may be a string, a reference to a
118 string, or a reference to an array. If it is a string or reference
119 to a string, it will be parsed into an array of items just as if it
120 were a command line string.
121 dump_options
123 If the dump_options parameter is given, it must be the reference to
124 a hash. In this case, the parameters contained in any perltidyrc
125 configuration file will be placed in this hash and perltidy will
126 return immediately. This is equivalent to running perltidy with
127 --dump-options, except that the parameters are returned in a hash
128 rather than dumped to standard output. Also, by default only the
129 parameters in the perltidyrc file are returned, but this can be
130 changed (see the next parameter). This parameter provides a
131 convenient method for external programs to read a perltidyrc file.
132 An example program using this feature, perltidyrc_dump.pl, is
133 included in the distribution.
134 Any combination of the dump_ parameters may be used together.
136 dump_options_type
138 This parameter is a string which can be used to control the
139 parameters placed in the hash reference supplied by dump_options.
140 The possible values are 'perltidyrc' (default) and 'full'. The
141 'full' parameter causes both the default options plus any options
142 found in a perltidyrc file to be returned.
143 dump_getopt_flags
145 If the dump_getopt_flags parameter is given, it must be the
146 reference to a hash. This hash will receive all of the parameters
147 that perltidy understands and flags that are passed to
148 Getopt::Long. This parameter may be used alone or with the
149 dump_options flag. Perltidy will exit immediately after filling
150 this hash. See the demo program perltidyrc_dump.pl for example
151 usage.
152 dump_options_category
154 If the dump_options_category parameter is given, it must be the
155 reference to a hash. This hash will receive a hash with keys equal
156 to all long parameter names and values equal to the title of the
157 corresponding section of the perltidy manual. See the demo program
158 perltidyrc_dump.pl for example usage.
159 dump_abbreviations
161 If the dump_abbreviations parameter is given, it must be the
162 reference to a hash. This hash will receive all abbreviations used
163 by Perl::Tidy. See the demo program perltidyrc_dump.pl for example
164 usage.
165 prefilter
167 A code reference that will be applied to the source before tidying.
168 It is expected to take the full content as a string in its input,
169 and output the transformed content.
170 postfilter
172 A code reference that will be applied to the tidied result before
173 outputting. It is expected to take the full content as a string in
174 its input, and output the transformed content.
175 Note: A convenient way to check the function of your custom
177 prefilter and postfilter code is to use the --notidy option, first
178 with just the prefilter and then with both the prefilter and
179 postfilter. See also the file filter_example.pl in the perltidy
180 distribution.
181
183 An exit value of 0, 1, or 2 is returned by perltidy to indicate the
184 status of the result.
185 A exit value of 0 indicates that perltidy ran to completion with no
187 error messages.
188 An exit value of 1 indicates that the process had to be terminated
190 early due to errors in the input parameters. This can happen for
191 example if a parameter is misspelled or given an invalid value. The
192 calling program should check for this flag because if it is set the
193 destination stream will be empty or incomplete and should be ignored.
194 Error messages in the stderr stream will indicate the cause of any
195 problem.
196 An exit value of 2 indicates that perltidy ran to completion but there
198 there are warning messages in the stderr stream related to parameter
199 errors or conflicts and/or warning messages in the errorfile stream
200 relating to possible syntax errors in the source code being tidied.
201 In the event of a catastrophic error for which recovery is not possible
203 perltidy terminates by making calls to croak or confess to help the
204 programmer localize the problem. These should normally only occur
205 during program development.
206
208 Parameters which control formatting may be passed in several ways: in a
209 .perltidyrc configuration file, in the perltidyrc parameter, and in the
210 argv parameter.
211 The -syn (--check-syntax) flag may be used with all source and
213 destination streams except for standard input and output. However data
214 streams which are not associated with a filename will be copied to a
215 temporary file before being passed to Perl. This use of temporary
216 files can cause somewhat confusing output from Perl.
217 If the -pbp style is used it will typically be necessary to also
219 specify a -nst flag. This is necessary to turn off the -st flag
220 contained in the -pbp parameter set which otherwise would direct the
221 output stream to the standard output.
222
224 The following example uses string references to hold the input and
225 output code and error streams, and illustrates checking for errors.
226 use Perl::Tidy;
228 my $source_string = <<'EOT';
230 my$error=Perl::Tidy::perltidy(argv=>$argv,source=>\$source_string,
231 destination=>\$dest_string,stderr=>\$stderr_string,
232 errorfile=>\$errorfile_string,);
233 EOT
234 my $dest_string;
236 my $stderr_string;
237 my $errorfile_string;
238 my $argv = "-npro"; # Ignore any .perltidyrc at this site
239 $argv .= " -pbp"; # Format according to perl best practices
240 $argv .= " -nst"; # Must turn off -st in case -pbp is specified
241 $argv .= " -se"; # -se appends the errorfile to stderr
242 ## $argv .= " --spell-check"; # uncomment to trigger an error
243 print "<<RAW SOURCE>>\n$source_string\n";
245 my $error = Perl::Tidy::perltidy(
247 argv => $argv,
248 source => \$source_string,
249 destination => \$dest_string,
250 stderr => \$stderr_string,
251 errorfile => \$errorfile_string, # ignored when -se flag is set
252 ##phasers => 'stun', # uncomment to trigger an error
253 );
254 if ($error) {
256 # serious error in input parameters, no tidied output
258 print "<<STDERR>>\n$stderr_string\n";
259 die "Exiting because of serious errors\n";
260 }
261 if ($dest_string) { print "<<TIDIED SOURCE>>\n$dest_string\n" }
263 if ($stderr_string) { print "<<STDERR>>\n$stderr_string\n" }
264 if ($errorfile_string) { print "<<.ERR file>>\n$errorfile_string\n" }
265 Additional examples are given in examples section of the perltidy
267 distribution.
268
270 The formatter parameter is an optional callback object which allows the
271 calling program to receive tokenized lines directly from perltidy for
272 further specialized processing. When this parameter is used, the two
273 formatting options which are built into perltidy (beautification or
274 html) are ignored. The following diagram illustrates the logical flow:
275 |-- (normal route) -> code beautification
277 caller->perltidy->|-- (-html flag ) -> create html
278 |-- (formatter given)-> callback to write_line
279 This can be useful for processing perl scripts in some way. The
281 parameter $formatter in the perltidy call,
282 formatter => $formatter,
284 is an object created by the caller with a "write_line" method which
286 will accept and process tokenized lines, one line per call. Here is a
287 simple example of a "write_line" which merely prints the line number,
288 the line type (as determined by perltidy), and the text of the line:
289 sub write_line {
291 # This is called from perltidy line-by-line
293 my $self = shift;
294 my $line_of_tokens = shift;
295 my $line_type = $line_of_tokens->{_line_type};
296 my $input_line_number = $line_of_tokens->{_line_number};
297 my $input_line = $line_of_tokens->{_line_text};
298 print "$input_line_number:$line_type:$input_line";
299 }
300 The complete program, perllinetype, is contained in the examples
302 section of the source distribution. As this example shows, the
303 callback method receives a parameter $line_of_tokens, which is a
304 reference to a hash of other useful information. This example uses
305 these hash entries:
306 $line_of_tokens->{_line_number} - the line number (1,2,...)
308 $line_of_tokens->{_line_text} - the text of the line
309 $line_of_tokens->{_line_type} - the type of the line, one of:
310 SYSTEM - system-specific code before hash-bang line
312 CODE - line of perl code (including comments)
313 POD_START - line starting pod, such as '=head'
314 POD - pod documentation text
315 POD_END - last line of pod section, '=cut'
316 HERE - text of here-document
317 HERE_END - last line of here-doc (target word)
318 FORMAT - format section
319 FORMAT_END - last line of format section, '.'
320 DATA_START - __DATA__ line
321 DATA - unidentified text following __DATA__
322 END_START - __END__ line
323 END - unidentified text following __END__
324 ERROR - we are in big trouble, probably not a perl script
325 Most applications will be only interested in lines of type CODE. For
327 another example, let's write a program which checks for one of the so-
328 called naughty matching variables "&`", $&, and "$'", which can slow
329 down processing. Here is a write_line, from the example program
330 find_naughty.pl, which does that:
331 sub write_line {
333 # This is called back from perltidy line-by-line
335 # We're looking for $`, $&, and $'
336 my ( $self, $line_of_tokens ) = @_;
337 # pull out some stuff we might need
339 my $line_type = $line_of_tokens->{_line_type};
340 my $input_line_number = $line_of_tokens->{_line_number};
341 my $input_line = $line_of_tokens->{_line_text};
342 my $rtoken_type = $line_of_tokens->{_rtoken_type};
343 my $rtokens = $line_of_tokens->{_rtokens};
344 chomp $input_line;
345 # skip comments, pod, etc
347 return if ( $line_type ne 'CODE' );
348 # loop over tokens looking for $`, $&, and $'
350 for ( my $j = 0 ; $j < @$rtoken_type ; $j++ ) {
351 # we only want to examine token types 'i' (identifier)
353 next unless $$rtoken_type[$j] eq 'i';
354 # pull out the actual token text
356 my $token = $$rtokens[$j];
357 # and check it
359 if ( $token =~ /^\$[\`\&\']$/ ) {
360 print STDERR
361 "$input_line_number: $token\n";
362 }
363 }
364 }
365 This example pulls out these tokenization variables from the
367 $line_of_tokens hash reference:
368 $rtoken_type = $line_of_tokens->{_rtoken_type};
370 $rtokens = $line_of_tokens->{_rtokens};
371 The variable $rtoken_type is a reference to an array of token type
373 codes, and $rtokens is a reference to a corresponding array of token
374 text. These are obviously only defined for lines of type CODE.
375 Perltidy classifies tokens into types, and has a brief code for each
376 type. You can get a complete list at any time by running perltidy from
377 the command line with
378 perltidy --dump-token-types
380 In the present example, we are only looking for tokens of type i
382 (identifiers), so the for loop skips past all other types. When an
383 identifier is found, its actual text is checked to see if it is one
384 being sought. If so, the above write_line prints the token and its
385 line number.
386 The formatter feature is relatively new in perltidy, and further
388 documentation needs to be written to complete its description.
389 However, several example programs have been written and can be found in
390 the examples section of the source distribution. Probably the best way
391 to get started is to find one of the examples which most closely
392 matches your application and start modifying it.
393 For help with perltidy's peculiar way of breaking lines into tokens,
395 you might run, from the command line,
396 perltidy -D filename
398 where filename is a short script of interest. This will produce
400 filename.DEBUG with interleaved lines of text and their token types.
401 The -D flag has been in perltidy from the beginning for this purpose.
402 If you want to see the code which creates this file, it is
403 "write_debug_entry" in Tidy.pm.
404
406 &perltidy
407
409 The module 'Perl::Tidy' comes with a binary 'perltidy' which is
410 installed when the module is installed. The module name is case-
411 sensitive. For example, the basic command for installing with cpanm is
412 'cpanm Perl::Tidy'.
413
415 This man page documents Perl::Tidy version 20200110
416
418 This package is free software; you can redistribute it and/or modify it
419 under the terms of the "GNU General Public License".
420 Please refer to the file "COPYING" for details.
422
424 A list of current bugs and issues can be found at the CPAN site
425 <https://rt.cpan.org/Public/Dist/Display.html?Name=Perl-Tidy>
426 To report a new bug or problem, use the link on this page.
428 The source code repository is at
430 <https://github.com/perltidy/perltidy>.
431
433 The perltidy(1) man page describes all of the features of perltidy. It
434 can be found at http://perltidy.sourceforge.net.
435perl v5.30.1 2020-01-30 Perl::Tidy(3)