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 conveninent to combine the errorfile stream
106 with the stderr stream. This can be done by setting the -se
107 parameter, in which case this parameter is ignored.
108 logfile
110 The logfile parameter allows the calling program to capture the
111 stream that would otherwise go to a .LOG file. This stream is only
112 created if requested with a -g parameter. It contains detailed
113 diagnostic information about a script which may be useful for
114 debugging.
115 argv
117 If the argv parameter is given, it will be used instead of the
118 @ARGV array. The argv parameter may be a string, a reference to a
119 string, or a reference to an array. If it is a string or reference
120 to a string, it will be parsed into an array of items just as if it
121 were a command line string.
122 dump_options
124 If the dump_options parameter is given, it must be the reference to
125 a hash. In this case, the parameters contained in any perltidyrc
126 configuration file will be placed in this hash and perltidy will
127 return immediately. This is equivalent to running perltidy with
128 --dump-options, except that the perameters are returned in a hash
129 rather than dumped to standard output. Also, by default only the
130 parameters in the perltidyrc file are returned, but this can be
131 changed (see the next parameter). This parameter provides a
132 convenient method for external programs to read a perltidyrc file.
133 An example program using this feature, perltidyrc_dump.pl, is
134 included in the distribution.
135 Any combination of the dump_ parameters may be used together.
137 dump_options_type
139 This parameter is a string which can be used to control the
140 parameters placed in the hash reference supplied by dump_options.
141 The possible values are 'perltidyrc' (default) and 'full'. The
142 'full' parameter causes both the default options plus any options
143 found in a perltidyrc file to be returned.
144 dump_getopt_flags
146 If the dump_getopt_flags parameter is given, it must be the
147 reference to a hash. This hash will receive all of the parameters
148 that perltidy understands and flags that are passed to
149 Getopt::Long. This parameter may be used alone or with the
150 dump_options flag. Perltidy will exit immediately after filling
151 this hash. See the demo program perltidyrc_dump.pl for example
152 usage.
153 dump_options_category
155 If the dump_options_category parameter is given, it must be the
156 reference to a hash. This hash will receive a hash with keys equal
157 to all long parameter names and values equal to the title of the
158 corresponding section of the perltidy manual. See the demo program
159 perltidyrc_dump.pl for example usage.
160 dump_abbreviations
162 If the dump_abbreviations parameter is given, it must be the
163 reference to a hash. This hash will receive all abbreviations used
164 by Perl::Tidy. See the demo program perltidyrc_dump.pl for example
165 usage.
166 prefilter
168 A code reference that will be applied to the source before tidying.
169 It is expected to take the full content as a string in its input,
170 and output the transformed content.
171 postfilter
173 A code reference that will be applied to the tidied result before
174 outputting. It is expected to take the full content as a string in
175 its input, and output the transformed content.
176 Note: A convenient way to check the function of your custom
178 prefilter and postfilter code is to use the --notidy option, first
179 with just the prefilter and then with both the prefilter and
180 postfilter. See also the file filter_example.pl in the perltidy
181 distribution.
182
184 Perltidy will return with an error flag indicating if the process had
185 to be terminated early due to errors in the input parameters. This can
186 happen for example if a parameter is misspelled or given an invalid
187 value. The calling program should check this flag because if it is set
188 the destination stream will be empty or incomplete and should be
189 ignored. Error messages in the stderr stream will indicate the cause
190 of any problem.
191 If the error flag is not set then perltidy ran to completion. However
193 there may still be warning messages in the stderr stream related to
194 control parameters, and there may be warning messages in the errorfile
195 stream relating to possible syntax errors in the source code being
196 tidied.
197 In the event of a catastrophic error for which recovery is not possible
199 perltidy terminates by making calls to croak or confess to help the
200 programmer localize the problem. These should normally only occur
201 during program development.
202
204 Parameters which control formatting may be passed in several ways: in a
205 .perltidyrc configuration file, in the perltidyrc parameter, and in the
206 argv parameter.
207 The -syn (--check-syntax) flag may be used with all source and
209 destination streams except for standard input and output. However data
210 streams which are not associated with a filename will be copied to a
211 temporary file before being be passed to Perl. This use of temporary
212 files can cause somewhat confusing output from Perl.
213 If the -pbp style is used it will typically be necessary to also
215 specify a -nst flag. This is necessary to turn off the -st flag
216 contained in the -pbp parameter set which otherwise would direct the
217 output stream to the standard output.
218
220 The following example uses string references to hold the input and
221 output code and error streams, and illustrates checking for errors.
222 use Perl::Tidy;
224 my $source_string = <<'EOT';
226 my$error=Perl::Tidy::perltidy(argv=>$argv,source=>\$source_string,
227 destination=>\$dest_string,stderr=>\$stderr_string,
228 errorfile=>\$errorfile_string,);
229 EOT
230 my $dest_string;
232 my $stderr_string;
233 my $errorfile_string;
234 my $argv = "-npro"; # Ignore any .perltidyrc at this site
235 $argv .= " -pbp"; # Format according to perl best practices
236 $argv .= " -nst"; # Must turn off -st in case -pbp is specified
237 $argv .= " -se"; # -se appends the errorfile to stderr
238 ## $argv .= " --spell-check"; # uncomment to trigger an error
239 print "<<RAW SOURCE>>\n$source_string\n";
241 my $error = Perl::Tidy::perltidy(
243 argv => $argv,
244 source => \$source_string,
245 destination => \$dest_string,
246 stderr => \$stderr_string,
247 errorfile => \$errorfile_string, # ignored when -se flag is set
248 ##phasers => 'stun', # uncomment to trigger an error
249 );
250 if ($error) {
252 # serious error in input parameters, no tidied output
254 print "<<STDERR>>\n$stderr_string\n";
255 die "Exiting because of serious errors\n";
256 }
257 if ($dest_string) { print "<<TIDIED SOURCE>>\n$dest_string\n" }
259 if ($stderr_string) { print "<<STDERR>>\n$stderr_string\n" }
260 if ($errorfile_string) { print "<<.ERR file>>\n$errorfile_string\n" }
261 Additional examples are given in examples section of the perltidy
263 distribution.
264
266 The formatter parameter is an optional callback object which allows the
267 calling program to receive tokenized lines directly from perltidy for
268 further specialized processing. When this parameter is used, the two
269 formatting options which are built into perltidy (beautification or
270 html) are ignored. The following diagram illustrates the logical flow:
271 |-- (normal route) -> code beautification
273 caller->perltidy->|-- (-html flag ) -> create html
274 |-- (formatter given)-> callback to write_line
275 This can be useful for processing perl scripts in some way. The
277 parameter $formatter in the perltidy call,
278 formatter => $formatter,
280 is an object created by the caller with a "write_line" method which
282 will accept and process tokenized lines, one line per call. Here is a
283 simple example of a "write_line" which merely prints the line number,
284 the line type (as determined by perltidy), and the text of the line:
285 sub write_line {
287 # This is called from perltidy line-by-line
289 my $self = shift;
290 my $line_of_tokens = shift;
291 my $line_type = $line_of_tokens->{_line_type};
292 my $input_line_number = $line_of_tokens->{_line_number};
293 my $input_line = $line_of_tokens->{_line_text};
294 print "$input_line_number:$line_type:$input_line";
295 }
296 The complete program, perllinetype, is contained in the examples
298 section of the source distribution. As this example shows, the
299 callback method receives a parameter $line_of_tokens, which is a
300 reference to a hash of other useful information. This example uses
301 these hash entries:
302 $line_of_tokens->{_line_number} - the line number (1,2,...)
304 $line_of_tokens->{_line_text} - the text of the line
305 $line_of_tokens->{_line_type} - the type of the line, one of:
306 SYSTEM - system-specific code before hash-bang line
308 CODE - line of perl code (including comments)
309 POD_START - line starting pod, such as '=head'
310 POD - pod documentation text
311 POD_END - last line of pod section, '=cut'
312 HERE - text of here-document
313 HERE_END - last line of here-doc (target word)
314 FORMAT - format section
315 FORMAT_END - last line of format section, '.'
316 DATA_START - __DATA__ line
317 DATA - unidentified text following __DATA__
318 END_START - __END__ line
319 END - unidentified text following __END__
320 ERROR - we are in big trouble, probably not a perl script
321 Most applications will be only interested in lines of type CODE. For
323 another example, let's write a program which checks for one of the so-
324 called naughty matching variables "&`", $&, and "$'", which can slow
325 down processing. Here is a write_line, from the example program
326 find_naughty.pl, which does that:
327 sub write_line {
329 # This is called back from perltidy line-by-line
331 # We're looking for $`, $&, and $'
332 my ( $self, $line_of_tokens ) = @_;
333 # pull out some stuff we might need
335 my $line_type = $line_of_tokens->{_line_type};
336 my $input_line_number = $line_of_tokens->{_line_number};
337 my $input_line = $line_of_tokens->{_line_text};
338 my $rtoken_type = $line_of_tokens->{_rtoken_type};
339 my $rtokens = $line_of_tokens->{_rtokens};
340 chomp $input_line;
341 # skip comments, pod, etc
343 return if ( $line_type ne 'CODE' );
344 # loop over tokens looking for $`, $&, and $'
346 for ( my $j = 0 ; $j < @$rtoken_type ; $j++ ) {
347 # we only want to examine token types 'i' (identifier)
349 next unless $$rtoken_type[$j] eq 'i';
350 # pull out the actual token text
352 my $token = $$rtokens[$j];
353 # and check it
355 if ( $token =~ /^\$[\`\&\']$/ ) {
356 print STDERR
357 "$input_line_number: $token\n";
358 }
359 }
360 }
361 This example pulls out these tokenization variables from the
363 $line_of_tokens hash reference:
364 $rtoken_type = $line_of_tokens->{_rtoken_type};
366 $rtokens = $line_of_tokens->{_rtokens};
367 The variable $rtoken_type is a reference to an array of token type
369 codes, and $rtokens is a reference to a corresponding array of token
370 text. These are obviously only defined for lines of type CODE.
371 Perltidy classifies tokens into types, and has a brief code for each
372 type. You can get a complete list at any time by running perltidy from
373 the command line with
374 perltidy --dump-token-types
376 In the present example, we are only looking for tokens of type i
378 (identifiers), so the for loop skips past all other types. When an
379 identifier is found, its actual text is checked to see if it is one
380 being sought. If so, the above write_line prints the token and its
381 line number.
382 The formatter feature is relatively new in perltidy, and further
384 documentation needs to be written to complete its description.
385 However, several example programs have been written and can be found in
386 the examples section of the source distribution. Probably the best way
387 to get started is to find one of the examples which most closely
388 matches your application and start modifying it.
389 For help with perltidy's pecular way of breaking lines into tokens, you
391 might run, from the command line,
392 perltidy -D filename
394 where filename is a short script of interest. This will produce
396 filename.DEBUG with interleaved lines of text and their token types.
397 The -D flag has been in perltidy from the beginning for this purpose.
398 If you want to see the code which creates this file, it is
399 "write_debug_entry" in Tidy.pm.
400
402 &perltidy
403
405 Thanks to Hugh Myers who developed the initial modular interface to
406 perltidy.
407
409 This man page documents Perl::Tidy version 20121207.
410
412 This package is free software; you can redistribute it and/or modify it
413 under the terms of the "GNU General Public License".
414 Please refer to the file "COPYING" for details.
416
418 Steve Hancock
419 perltidy at users.sourceforge.net
420
422 The perltidy(1) man page describes all of the features of perltidy. It
423 can be found at http://perltidy.sourceforge.net.
424perl v5.16.3 2014-06-10 Perl::Tidy(3)