Commit | Line | Data |
823edd99 |
1 | # |
2 | # Data/Dumper.pm |
3 | # |
4 | # convert perl data structures into perl syntax suitable for both printing |
5 | # and eval |
6 | # |
7 | # Documentation at the __END__ |
8 | # |
9 | |
10 | package Data::Dumper; |
11 | |
c8984b0b |
12 | $VERSION = $VERSION = '2.101'; |
823edd99 |
13 | |
14 | #$| = 1; |
15 | |
16 | require 5.004; |
17 | require Exporter; |
18 | require DynaLoader; |
19 | require overload; |
20 | |
21 | use Carp; |
22 | |
23 | @ISA = qw(Exporter DynaLoader); |
24 | @EXPORT = qw(Dumper); |
25 | @EXPORT_OK = qw(DumperX); |
26 | |
27 | bootstrap Data::Dumper; |
28 | |
29 | # module vars and their defaults |
30 | $Indent = 2 unless defined $Indent; |
31 | $Purity = 0 unless defined $Purity; |
32 | $Pad = "" unless defined $Pad; |
33 | $Varname = "VAR" unless defined $Varname; |
34 | $Useqq = 0 unless defined $Useqq; |
35 | $Terse = 0 unless defined $Terse; |
36 | $Freezer = "" unless defined $Freezer; |
37 | $Toaster = "" unless defined $Toaster; |
38 | $Deepcopy = 0 unless defined $Deepcopy; |
39 | $Quotekeys = 1 unless defined $Quotekeys; |
40 | $Bless = "bless" unless defined $Bless; |
41 | #$Expdepth = 0 unless defined $Expdepth; |
42 | #$Maxdepth = 0 unless defined $Maxdepth; |
43 | |
44 | # |
45 | # expects an arrayref of values to be dumped. |
46 | # can optionally pass an arrayref of names for the values. |
47 | # names must have leading $ sign stripped. begin the name with * |
48 | # to cause output of arrays and hashes rather than refs. |
49 | # |
50 | sub new { |
51 | my($c, $v, $n) = @_; |
52 | |
53 | croak "Usage: PACKAGE->new(ARRAYREF, [ARRAYREF])" |
54 | unless (defined($v) && (ref($v) eq 'ARRAY')); |
55 | $n = [] unless (defined($n) && (ref($v) eq 'ARRAY')); |
56 | |
57 | my($s) = { |
58 | level => 0, # current recursive depth |
59 | indent => $Indent, # various styles of indenting |
60 | pad => $Pad, # all lines prefixed by this string |
61 | xpad => "", # padding-per-level |
62 | apad => "", # added padding for hash keys n such |
63 | sep => "", # list separator |
64 | seen => {}, # local (nested) refs (id => [name, val]) |
65 | todump => $v, # values to dump [] |
66 | names => $n, # optional names for values [] |
67 | varname => $Varname, # prefix to use for tagging nameless ones |
68 | purity => $Purity, # degree to which output is evalable |
69 | useqq => $Useqq, # use "" for strings (backslashitis ensues) |
70 | terse => $Terse, # avoid name output (where feasible) |
71 | freezer => $Freezer, # name of Freezer method for objects |
72 | toaster => $Toaster, # name of method to revive objects |
73 | deepcopy => $Deepcopy, # dont cross-ref, except to stop recursion |
74 | quotekeys => $Quotekeys, # quote hash keys |
75 | 'bless' => $Bless, # keyword to use for "bless" |
76 | # expdepth => $Expdepth, # cutoff depth for explicit dumping |
77 | # maxdepth => $Maxdepth, # depth beyond which we give up |
78 | }; |
79 | |
80 | if ($Indent > 0) { |
81 | $s->{xpad} = " "; |
82 | $s->{sep} = "\n"; |
83 | } |
84 | return bless($s, $c); |
85 | } |
86 | |
87 | # |
88 | # add-to or query the table of already seen references |
89 | # |
90 | sub Seen { |
91 | my($s, $g) = @_; |
92 | if (defined($g) && (ref($g) eq 'HASH')) { |
93 | my($k, $v, $id); |
94 | while (($k, $v) = each %$g) { |
95 | if (defined $v and ref $v) { |
96 | ($id) = (overload::StrVal($v) =~ /\((.*)\)$/); |
97 | if ($k =~ /^[*](.*)$/) { |
98 | $k = (ref $v eq 'ARRAY') ? ( "\\\@" . $1 ) : |
99 | (ref $v eq 'HASH') ? ( "\\\%" . $1 ) : |
100 | (ref $v eq 'CODE') ? ( "\\\&" . $1 ) : |
101 | ( "\$" . $1 ) ; |
102 | } |
103 | elsif ($k !~ /^\$/) { |
104 | $k = "\$" . $k; |
105 | } |
106 | $s->{seen}{$id} = [$k, $v]; |
107 | } |
108 | else { |
109 | carp "Only refs supported, ignoring non-ref item \$$k"; |
110 | } |
111 | } |
112 | return $s; |
113 | } |
114 | else { |
115 | return map { @$_ } values %{$s->{seen}}; |
116 | } |
117 | } |
118 | |
119 | # |
120 | # set or query the values to be dumped |
121 | # |
122 | sub Values { |
123 | my($s, $v) = @_; |
124 | if (defined($v) && (ref($v) eq 'ARRAY')) { |
125 | $s->{todump} = [@$v]; # make a copy |
126 | return $s; |
127 | } |
128 | else { |
129 | return @{$s->{todump}}; |
130 | } |
131 | } |
132 | |
133 | # |
134 | # set or query the names of the values to be dumped |
135 | # |
136 | sub Names { |
137 | my($s, $n) = @_; |
138 | if (defined($n) && (ref($n) eq 'ARRAY')) { |
139 | $s->{names} = [@$n]; # make a copy |
140 | return $s; |
141 | } |
142 | else { |
143 | return @{$s->{names}}; |
144 | } |
145 | } |
146 | |
147 | sub DESTROY {} |
148 | |
149 | # |
150 | # dump the refs in the current dumper object. |
151 | # expects same args as new() if called via package name. |
152 | # |
153 | sub Dump { |
154 | my($s) = shift; |
155 | my(@out, $val, $name); |
156 | my($i) = 0; |
157 | local(@post); |
158 | |
159 | $s = $s->new(@_) unless ref $s; |
160 | |
161 | for $val (@{$s->{todump}}) { |
162 | my $out = ""; |
163 | @post = (); |
164 | $name = $s->{names}[$i++]; |
165 | if (defined $name) { |
166 | if ($name =~ /^[*](.*)$/) { |
167 | if (defined $val) { |
168 | $name = (ref $val eq 'ARRAY') ? ( "\@" . $1 ) : |
169 | (ref $val eq 'HASH') ? ( "\%" . $1 ) : |
170 | (ref $val eq 'CODE') ? ( "\*" . $1 ) : |
171 | ( "\$" . $1 ) ; |
172 | } |
173 | else { |
174 | $name = "\$" . $1; |
175 | } |
176 | } |
177 | elsif ($name !~ /^\$/) { |
178 | $name = "\$" . $name; |
179 | } |
180 | } |
181 | else { |
182 | $name = "\$" . $s->{varname} . $i; |
183 | } |
184 | |
185 | my $valstr; |
186 | { |
187 | local($s->{apad}) = $s->{apad}; |
188 | $s->{apad} .= ' ' x (length($name) + 3) if $s->{indent} >= 2; |
189 | $valstr = $s->_dump($val, $name); |
190 | } |
191 | |
192 | $valstr = "$name = " . $valstr . ';' if @post or !$s->{terse}; |
193 | $out .= $s->{pad} . $valstr . $s->{sep}; |
194 | $out .= $s->{pad} . join(';' . $s->{sep} . $s->{pad}, @post) |
195 | . ';' . $s->{sep} if @post; |
196 | |
197 | push @out, $out; |
198 | } |
199 | return wantarray ? @out : join('', @out); |
200 | } |
201 | |
202 | # |
203 | # twist, toil and turn; |
204 | # and recurse, of course. |
205 | # |
206 | sub _dump { |
207 | my($s, $val, $name) = @_; |
208 | my($sname); |
209 | my($out, $realpack, $realtype, $type, $ipad, $id, $blesspad); |
210 | |
823edd99 |
211 | $type = ref $val; |
212 | $out = ""; |
213 | |
214 | if ($type) { |
215 | |
216 | # prep it, if it looks like an object |
217 | if ($type =~ /[a-z_:]/) { |
218 | my $freezer = $s->{freezer}; |
7820172a |
219 | $val->$freezer() if $freezer && UNIVERSAL::can($val, $freezer); |
823edd99 |
220 | } |
221 | |
222 | ($realpack, $realtype, $id) = |
223 | (overload::StrVal($val) =~ /^(?:(.*)\=)?([^=]*)\(([^\(]*)\)$/); |
224 | |
7820172a |
225 | # if it has a name, we need to either look it up, or keep a tab |
226 | # on it so we know when we hit it later |
227 | if (defined($name) and length($name)) { |
228 | # keep a tab on it so that we dont fall into recursive pit |
229 | if (exists $s->{seen}{$id}) { |
230 | # if ($s->{expdepth} < $s->{level}) { |
231 | if ($s->{purity} and $s->{level} > 0) { |
232 | $out = ($realtype eq 'HASH') ? '{}' : |
233 | ($realtype eq 'ARRAY') ? '[]' : |
234 | "''" ; |
235 | push @post, $name . " = " . $s->{seen}{$id}[0]; |
823edd99 |
236 | } |
237 | else { |
7820172a |
238 | $out = $s->{seen}{$id}[0]; |
239 | if ($name =~ /^([\@\%])/) { |
240 | my $start = $1; |
241 | if ($out =~ /^\\$start/) { |
242 | $out = substr($out, 1); |
243 | } |
244 | else { |
245 | $out = $start . '{' . $out . '}'; |
246 | } |
247 | } |
248 | } |
249 | return $out; |
250 | # } |
251 | } |
252 | else { |
253 | # store our name |
254 | $s->{seen}{$id} = [ (($name =~ /^[@%]/) ? ('\\' . $name ) : |
255 | ($realtype eq 'CODE' and |
256 | $name =~ /^[*](.*)$/) ? ('\\&' . $1 ) : |
257 | $name ), |
258 | $val ]; |
823edd99 |
259 | } |
823edd99 |
260 | } |
261 | |
7894fbab |
262 | if ($realpack) { |
263 | if ($realpack eq 'Regexp') { |
264 | $out = "$val"; |
265 | $out =~ s,/,\\/,g; |
266 | return "qr/$out/"; |
267 | } |
268 | else { # we have a blessed ref |
269 | $out = $s->{'bless'} . '( '; |
270 | $blesspad = $s->{apad}; |
271 | $s->{apad} .= ' ' if ($s->{indent} >= 2); |
272 | } |
273 | } |
274 | |
823edd99 |
275 | $s->{level}++; |
276 | $ipad = $s->{xpad} x $s->{level}; |
277 | |
823edd99 |
278 | |
279 | if ($realtype eq 'SCALAR') { |
280 | if ($realpack) { |
7820172a |
281 | $out .= 'do{\\(my $o = ' . $s->_dump($$val, "\${$name}") . ')}'; |
823edd99 |
282 | } |
283 | else { |
7820172a |
284 | $out .= '\\' . $s->_dump($$val, "\${$name}"); |
823edd99 |
285 | } |
286 | } |
287 | elsif ($realtype eq 'GLOB') { |
7820172a |
288 | $out .= '\\' . $s->_dump($$val, "*{$name}"); |
823edd99 |
289 | } |
290 | elsif ($realtype eq 'ARRAY') { |
291 | my($v, $pad, $mname); |
292 | my($i) = 0; |
293 | $out .= ($name =~ /^\@/) ? '(' : '['; |
294 | $pad = $s->{sep} . $s->{pad} . $s->{apad}; |
295 | ($name =~ /^\@(.*)$/) ? ($mname = "\$" . $1) : |
7820172a |
296 | # omit -> if $foo->[0]->{bar}, but not ${$foo->[0]}->{bar} |
297 | ($name =~ /^\\?[\%\@\*\$][^{].*[]}]$/) ? ($mname = $name) : |
298 | ($mname = $name . '->'); |
823edd99 |
299 | $mname .= '->' if $mname =~ /^\*.+\{[A-Z]+\}$/; |
300 | for $v (@$val) { |
301 | $sname = $mname . '[' . $i . ']'; |
302 | $out .= $pad . $ipad . '#' . $i if $s->{indent} >= 3; |
303 | $out .= $pad . $ipad . $s->_dump($v, $sname); |
304 | $out .= "," if $i++ < $#$val; |
305 | } |
306 | $out .= $pad . ($s->{xpad} x ($s->{level} - 1)) if $i; |
307 | $out .= ($name =~ /^\@/) ? ')' : ']'; |
308 | } |
309 | elsif ($realtype eq 'HASH') { |
310 | my($k, $v, $pad, $lpad, $mname); |
311 | $out .= ($name =~ /^\%/) ? '(' : '{'; |
312 | $pad = $s->{sep} . $s->{pad} . $s->{apad}; |
313 | $lpad = $s->{apad}; |
7820172a |
314 | ($name =~ /^\%(.*)$/) ? ($mname = "\$" . $1) : |
315 | # omit -> if $foo->[0]->{bar}, but not ${$foo->[0]}->{bar} |
316 | ($name =~ /^\\?[\%\@\*\$][^{].*[]}]$/) ? ($mname = $name) : |
317 | ($mname = $name . '->'); |
823edd99 |
318 | $mname .= '->' if $mname =~ /^\*.+\{[A-Z]+\}$/; |
319 | while (($k, $v) = each %$val) { |
320 | my $nk = $s->_dump($k, ""); |
321 | $nk = $1 if !$s->{quotekeys} and $nk =~ /^[\"\']([A-Za-z_]\w*)[\"\']$/; |
322 | $sname = $mname . '{' . $nk . '}'; |
323 | $out .= $pad . $ipad . $nk . " => "; |
324 | |
325 | # temporarily alter apad |
326 | $s->{apad} .= (" " x (length($nk) + 4)) if $s->{indent} >= 2; |
327 | $out .= $s->_dump($val->{$k}, $sname) . ","; |
328 | $s->{apad} = $lpad if $s->{indent} >= 2; |
329 | } |
330 | if (substr($out, -1) eq ',') { |
331 | chop $out; |
332 | $out .= $pad . ($s->{xpad} x ($s->{level} - 1)); |
333 | } |
334 | $out .= ($name =~ /^\%/) ? ')' : '}'; |
335 | } |
336 | elsif ($realtype eq 'CODE') { |
c8984b0b |
337 | $out .= 'sub { "DUMMY" }'; |
823edd99 |
338 | carp "Encountered CODE ref, using dummy placeholder" if $s->{purity}; |
339 | } |
340 | else { |
341 | croak "Can\'t handle $realtype type."; |
342 | } |
343 | |
344 | if ($realpack) { # we have a blessed ref |
345 | $out .= ', \'' . $realpack . '\'' . ' )'; |
346 | $out .= '->' . $s->{toaster} . '()' if $s->{toaster} ne ''; |
347 | $s->{apad} = $blesspad; |
348 | } |
349 | $s->{level}--; |
350 | |
351 | } |
352 | else { # simple scalar |
353 | |
354 | my $ref = \$_[1]; |
355 | # first, catalog the scalar |
356 | if ($name ne '') { |
357 | ($id) = ("$ref" =~ /\(([^\(]*)\)$/); |
358 | if (exists $s->{seen}{$id}) { |
7820172a |
359 | if ($s->{seen}{$id}[2]) { |
360 | $out = $s->{seen}{$id}[0]; |
361 | #warn "[<$out]\n"; |
362 | return "\${$out}"; |
363 | } |
823edd99 |
364 | } |
365 | else { |
7820172a |
366 | #warn "[>\\$name]\n"; |
367 | $s->{seen}{$id} = ["\\$name", $ref]; |
823edd99 |
368 | } |
369 | } |
370 | if (ref($ref) eq 'GLOB' or "$ref" =~ /=GLOB\([^()]+\)$/) { # glob |
371 | my $name = substr($val, 1); |
372 | if ($name =~ /^[A-Za-z_][\w:]*$/) { |
373 | $name =~ s/^main::/::/; |
374 | $sname = $name; |
375 | } |
376 | else { |
377 | $sname = $s->_dump($name, ""); |
378 | $sname = '{' . $sname . '}'; |
379 | } |
380 | if ($s->{purity}) { |
381 | my $k; |
382 | local ($s->{level}) = 0; |
383 | for $k (qw(SCALAR ARRAY HASH)) { |
7820172a |
384 | my $gval = *$val{$k}; |
385 | next unless defined $gval; |
386 | next if $k eq "SCALAR" && ! defined $$gval; # always there |
387 | |
823edd99 |
388 | # _dump can push into @post, so we hold our place using $postlen |
389 | my $postlen = scalar @post; |
390 | $post[$postlen] = "\*$sname = "; |
391 | local ($s->{apad}) = " " x length($post[$postlen]) if $s->{indent} >= 2; |
7820172a |
392 | $post[$postlen] .= $s->_dump($gval, "\*$sname\{$k\}"); |
823edd99 |
393 | } |
394 | } |
395 | $out .= '*' . $sname; |
396 | } |
7820172a |
397 | elsif (!defined($val)) { |
398 | $out .= "undef"; |
399 | } |
45b49486 |
400 | elsif ($val =~ /^(?:0|-?[1-9]\d{0,8})$/) { # safe decimal number |
823edd99 |
401 | $out .= $val; |
402 | } |
403 | else { # string |
404 | if ($s->{useqq}) { |
7820172a |
405 | $out .= qquote($val, $s->{useqq}); |
823edd99 |
406 | } |
407 | else { |
408 | $val =~ s/([\\\'])/\\$1/g; |
409 | $out .= '\'' . $val . '\''; |
410 | } |
411 | } |
412 | } |
7820172a |
413 | if ($id) { |
414 | # if we made it this far, $id was added to seen list at current |
415 | # level, so remove it to get deep copies |
416 | if ($s->{deepcopy}) { |
417 | delete($s->{seen}{$id}); |
418 | } |
419 | elsif ($name) { |
420 | $s->{seen}{$id}[2] = 1; |
421 | } |
422 | } |
823edd99 |
423 | return $out; |
424 | } |
425 | |
426 | # |
427 | # non-OO style of earlier version |
428 | # |
429 | sub Dumper { |
430 | return Data::Dumper->Dump([@_]); |
431 | } |
432 | |
433 | # |
434 | # same, only calls the XS version |
435 | # |
436 | sub DumperX { |
437 | return Data::Dumper->Dumpxs([@_], []); |
438 | } |
439 | |
440 | sub Dumpf { return Data::Dumper->Dump(@_) } |
441 | |
442 | sub Dumpp { print Data::Dumper->Dump(@_) } |
443 | |
444 | # |
445 | # reset the "seen" cache |
446 | # |
447 | sub Reset { |
448 | my($s) = shift; |
449 | $s->{seen} = {}; |
450 | return $s; |
451 | } |
452 | |
453 | sub Indent { |
454 | my($s, $v) = @_; |
455 | if (defined($v)) { |
456 | if ($v == 0) { |
457 | $s->{xpad} = ""; |
458 | $s->{sep} = ""; |
459 | } |
460 | else { |
461 | $s->{xpad} = " "; |
462 | $s->{sep} = "\n"; |
463 | } |
464 | $s->{indent} = $v; |
465 | return $s; |
466 | } |
467 | else { |
468 | return $s->{indent}; |
469 | } |
470 | } |
471 | |
472 | sub Pad { |
473 | my($s, $v) = @_; |
474 | defined($v) ? (($s->{pad} = $v), return $s) : $s->{pad}; |
475 | } |
476 | |
477 | sub Varname { |
478 | my($s, $v) = @_; |
479 | defined($v) ? (($s->{varname} = $v), return $s) : $s->{varname}; |
480 | } |
481 | |
482 | sub Purity { |
483 | my($s, $v) = @_; |
484 | defined($v) ? (($s->{purity} = $v), return $s) : $s->{purity}; |
485 | } |
486 | |
487 | sub Useqq { |
488 | my($s, $v) = @_; |
489 | defined($v) ? (($s->{useqq} = $v), return $s) : $s->{useqq}; |
490 | } |
491 | |
492 | sub Terse { |
493 | my($s, $v) = @_; |
494 | defined($v) ? (($s->{terse} = $v), return $s) : $s->{terse}; |
495 | } |
496 | |
497 | sub Freezer { |
498 | my($s, $v) = @_; |
499 | defined($v) ? (($s->{freezer} = $v), return $s) : $s->{freezer}; |
500 | } |
501 | |
502 | sub Toaster { |
503 | my($s, $v) = @_; |
504 | defined($v) ? (($s->{toaster} = $v), return $s) : $s->{toaster}; |
505 | } |
506 | |
507 | sub Deepcopy { |
508 | my($s, $v) = @_; |
509 | defined($v) ? (($s->{deepcopy} = $v), return $s) : $s->{deepcopy}; |
510 | } |
511 | |
512 | sub Quotekeys { |
513 | my($s, $v) = @_; |
514 | defined($v) ? (($s->{quotekeys} = $v), return $s) : $s->{quotekeys}; |
515 | } |
516 | |
517 | sub Bless { |
518 | my($s, $v) = @_; |
519 | defined($v) ? (($s->{'bless'} = $v), return $s) : $s->{'bless'}; |
520 | } |
521 | |
7820172a |
522 | # used by qquote below |
523 | my %esc = ( |
524 | "\a" => "\\a", |
525 | "\b" => "\\b", |
526 | "\t" => "\\t", |
527 | "\n" => "\\n", |
528 | "\f" => "\\f", |
529 | "\r" => "\\r", |
530 | "\e" => "\\e", |
531 | ); |
532 | |
823edd99 |
533 | # put a string value in double quotes |
534 | sub qquote { |
535 | local($_) = shift; |
7820172a |
536 | s/([\\\"\@\$])/\\$1/g; |
537 | return qq("$_") unless /[^\040-\176]/; # fast exit |
538 | |
539 | my $high = shift || ""; |
540 | s/([\a\b\t\n\f\r\e])/$esc{$1}/g; |
541 | |
542 | # no need for 3 digits in escape for these |
543 | s/([\0-\037])(?!\d)/'\\'.sprintf('%o',ord($1))/eg; |
544 | |
545 | s/([\0-\037\177])/'\\'.sprintf('%03o',ord($1))/eg; |
546 | if ($high eq "iso8859") { |
547 | s/([\200-\240])/'\\'.sprintf('%o',ord($1))/eg; |
548 | } elsif ($high eq "utf8") { |
549 | # use utf8; |
550 | # $str =~ s/([^\040-\176])/sprintf "\\x{%04x}", ord($1)/ge; |
551 | } elsif ($high eq "8bit") { |
552 | # leave it as it is |
553 | } else { |
554 | s/([\0-\037\177-\377])/'\\'.sprintf('%03o',ord($1))/eg; |
555 | } |
556 | return qq("$_"); |
823edd99 |
557 | } |
558 | |
559 | 1; |
560 | __END__ |
561 | |
562 | =head1 NAME |
563 | |
564 | Data::Dumper - stringified perl data structures, suitable for both printing and C<eval> |
565 | |
566 | |
567 | =head1 SYNOPSIS |
568 | |
569 | use Data::Dumper; |
570 | |
571 | # simple procedural interface |
572 | print Dumper($foo, $bar); |
573 | |
574 | # extended usage with names |
575 | print Data::Dumper->Dump([$foo, $bar], [qw(foo *ary)]); |
576 | |
577 | # configuration variables |
578 | { |
579 | local $Data::Dump::Purity = 1; |
580 | eval Data::Dumper->Dump([$foo, $bar], [qw(foo *ary)]); |
581 | } |
582 | |
583 | # OO usage |
584 | $d = Data::Dumper->new([$foo, $bar], [qw(foo *ary)]); |
585 | ... |
586 | print $d->Dump; |
587 | ... |
588 | $d->Purity(1)->Terse(1)->Deepcopy(1); |
589 | eval $d->Dump; |
590 | |
591 | |
592 | =head1 DESCRIPTION |
593 | |
594 | Given a list of scalars or reference variables, writes out their contents in |
595 | perl syntax. The references can also be objects. The contents of each |
596 | variable is output in a single Perl statement. Handles self-referential |
597 | structures correctly. |
598 | |
599 | The return value can be C<eval>ed to get back an identical copy of the |
600 | original reference structure. |
601 | |
602 | Any references that are the same as one of those passed in will be named |
603 | C<$VAR>I<n> (where I<n> is a numeric suffix), and other duplicate references |
604 | to substructures within C<$VAR>I<n> will be appropriately labeled using arrow |
605 | notation. You can specify names for individual values to be dumped if you |
606 | use the C<Dump()> method, or you can change the default C<$VAR> prefix to |
607 | something else. See C<$Data::Dumper::Varname> and C<$Data::Dumper::Terse> |
608 | below. |
609 | |
610 | The default output of self-referential structures can be C<eval>ed, but the |
611 | nested references to C<$VAR>I<n> will be undefined, since a recursive |
612 | structure cannot be constructed using one Perl statement. You should set the |
613 | C<Purity> flag to 1 to get additional statements that will correctly fill in |
614 | these references. |
615 | |
616 | In the extended usage form, the references to be dumped can be given |
617 | user-specified names. If a name begins with a C<*>, the output will |
618 | describe the dereferenced type of the supplied reference for hashes and |
619 | arrays, and coderefs. Output of names will be avoided where possible if |
620 | the C<Terse> flag is set. |
621 | |
622 | In many cases, methods that are used to set the internal state of the |
623 | object will return the object itself, so method calls can be conveniently |
624 | chained together. |
625 | |
626 | Several styles of output are possible, all controlled by setting |
627 | the C<Indent> flag. See L<Configuration Variables or Methods> below |
628 | for details. |
629 | |
630 | |
631 | =head2 Methods |
632 | |
633 | =over 4 |
634 | |
635 | =item I<PACKAGE>->new(I<ARRAYREF [>, I<ARRAYREF]>) |
636 | |
637 | Returns a newly created C<Data::Dumper> object. The first argument is an |
638 | anonymous array of values to be dumped. The optional second argument is an |
639 | anonymous array of names for the values. The names need not have a leading |
640 | C<$> sign, and must be comprised of alphanumeric characters. You can begin |
641 | a name with a C<*> to specify that the dereferenced type must be dumped |
642 | instead of the reference itself, for ARRAY and HASH references. |
643 | |
644 | The prefix specified by C<$Data::Dumper::Varname> will be used with a |
645 | numeric suffix if the name for a value is undefined. |
646 | |
647 | Data::Dumper will catalog all references encountered while dumping the |
648 | values. Cross-references (in the form of names of substructures in perl |
649 | syntax) will be inserted at all possible points, preserving any structural |
650 | interdependencies in the original set of values. Structure traversal is |
651 | depth-first, and proceeds in order from the first supplied value to |
652 | the last. |
653 | |
654 | =item I<$OBJ>->Dump I<or> I<PACKAGE>->Dump(I<ARRAYREF [>, I<ARRAYREF]>) |
655 | |
656 | Returns the stringified form of the values stored in the object (preserving |
657 | the order in which they were supplied to C<new>), subject to the |
658 | configuration options below. In an array context, it returns a list |
659 | of strings corresponding to the supplied values. |
660 | |
661 | The second form, for convenience, simply calls the C<new> method on its |
662 | arguments before dumping the object immediately. |
663 | |
664 | =item I<$OBJ>->Dumpxs I<or> I<PACKAGE>->Dumpxs(I<ARRAYREF [>, I<ARRAYREF]>) |
665 | |
666 | This method is available if you were able to compile and install the XSUB |
667 | extension to C<Data::Dumper>. It is exactly identical to the C<Dump> method |
668 | above, only about 4 to 5 times faster, since it is written entirely in C. |
669 | |
670 | =item I<$OBJ>->Seen(I<[HASHREF]>) |
671 | |
672 | Queries or adds to the internal table of already encountered references. |
673 | You must use C<Reset> to explicitly clear the table if needed. Such |
674 | references are not dumped; instead, their names are inserted wherever they |
675 | are encountered subsequently. This is useful especially for properly |
676 | dumping subroutine references. |
677 | |
678 | Expects a anonymous hash of name => value pairs. Same rules apply for names |
679 | as in C<new>. If no argument is supplied, will return the "seen" list of |
680 | name => value pairs, in an array context. Otherwise, returns the object |
681 | itself. |
682 | |
683 | =item I<$OBJ>->Values(I<[ARRAYREF]>) |
684 | |
685 | Queries or replaces the internal array of values that will be dumped. |
686 | When called without arguments, returns the values. Otherwise, returns the |
687 | object itself. |
688 | |
689 | =item I<$OBJ>->Names(I<[ARRAYREF]>) |
690 | |
691 | Queries or replaces the internal array of user supplied names for the values |
692 | that will be dumped. When called without arguments, returns the names. |
693 | Otherwise, returns the object itself. |
694 | |
695 | =item I<$OBJ>->Reset |
696 | |
697 | Clears the internal table of "seen" references and returns the object |
698 | itself. |
699 | |
700 | =back |
701 | |
702 | =head2 Functions |
703 | |
704 | =over 4 |
705 | |
706 | =item Dumper(I<LIST>) |
707 | |
708 | Returns the stringified form of the values in the list, subject to the |
709 | configuration options below. The values will be named C<$VAR>I<n> in the |
710 | output, where I<n> is a numeric suffix. Will return a list of strings |
711 | in an array context. |
712 | |
713 | =item DumperX(I<LIST>) |
714 | |
715 | Identical to the C<Dumper()> function above, but this calls the XSUB |
716 | implementation. Only available if you were able to compile and install |
717 | the XSUB extensions in C<Data::Dumper>. |
718 | |
719 | =back |
720 | |
721 | =head2 Configuration Variables or Methods |
722 | |
723 | Several configuration variables can be used to control the kind of output |
724 | generated when using the procedural interface. These variables are usually |
725 | C<local>ized in a block so that other parts of the code are not affected by |
726 | the change. |
727 | |
728 | These variables determine the default state of the object created by calling |
729 | the C<new> method, but cannot be used to alter the state of the object |
730 | thereafter. The equivalent method names should be used instead to query |
731 | or set the internal state of the object. |
732 | |
733 | The method forms return the object itself when called with arguments, |
734 | so that they can be chained together nicely. |
735 | |
736 | =over 4 |
737 | |
738 | =item $Data::Dumper::Indent I<or> I<$OBJ>->Indent(I<[NEWVAL]>) |
739 | |
740 | Controls the style of indentation. It can be set to 0, 1, 2 or 3. Style 0 |
741 | spews output without any newlines, indentation, or spaces between list |
742 | items. It is the most compact format possible that can still be called |
743 | valid perl. Style 1 outputs a readable form with newlines but no fancy |
744 | indentation (each level in the structure is simply indented by a fixed |
745 | amount of whitespace). Style 2 (the default) outputs a very readable form |
746 | which takes into account the length of hash keys (so the hash value lines |
747 | up). Style 3 is like style 2, but also annotates the elements of arrays |
748 | with their index (but the comment is on its own line, so array output |
749 | consumes twice the number of lines). Style 2 is the default. |
750 | |
751 | =item $Data::Dumper::Purity I<or> I<$OBJ>->Purity(I<[NEWVAL]>) |
752 | |
753 | Controls the degree to which the output can be C<eval>ed to recreate the |
754 | supplied reference structures. Setting it to 1 will output additional perl |
755 | statements that will correctly recreate nested references. The default is |
756 | 0. |
757 | |
758 | =item $Data::Dumper::Pad I<or> I<$OBJ>->Pad(I<[NEWVAL]>) |
759 | |
760 | Specifies the string that will be prefixed to every line of the output. |
761 | Empty string by default. |
762 | |
763 | =item $Data::Dumper::Varname I<or> I<$OBJ>->Varname(I<[NEWVAL]>) |
764 | |
765 | Contains the prefix to use for tagging variable names in the output. The |
766 | default is "VAR". |
767 | |
768 | =item $Data::Dumper::Useqq I<or> I<$OBJ>->Useqq(I<[NEWVAL]>) |
769 | |
770 | When set, enables the use of double quotes for representing string values. |
771 | Whitespace other than space will be represented as C<[\n\t\r]>, "unsafe" |
772 | characters will be backslashed, and unprintable characters will be output as |
773 | quoted octal integers. Since setting this variable imposes a performance |
774 | penalty, the default is 0. The C<Dumpxs()> method does not honor this |
775 | flag yet. |
776 | |
777 | =item $Data::Dumper::Terse I<or> I<$OBJ>->Terse(I<[NEWVAL]>) |
778 | |
779 | When set, Data::Dumper will emit single, non-self-referential values as |
780 | atoms/terms rather than statements. This means that the C<$VAR>I<n> names |
781 | will be avoided where possible, but be advised that such output may not |
782 | always be parseable by C<eval>. |
783 | |
784 | =item $Data::Dumper::Freezer I<or> $I<OBJ>->Freezer(I<[NEWVAL]>) |
785 | |
786 | Can be set to a method name, or to an empty string to disable the feature. |
787 | Data::Dumper will invoke that method via the object before attempting to |
788 | stringify it. This method can alter the contents of the object (if, for |
789 | instance, it contains data allocated from C), and even rebless it in a |
790 | different package. The client is responsible for making sure the specified |
791 | method can be called via the object, and that the object ends up containing |
792 | only perl data types after the method has been called. Defaults to an empty |
793 | string. |
794 | |
795 | =item $Data::Dumper::Toaster I<or> $I<OBJ>->Toaster(I<[NEWVAL]>) |
796 | |
797 | Can be set to a method name, or to an empty string to disable the feature. |
798 | Data::Dumper will emit a method call for any objects that are to be dumped |
799 | using the syntax C<bless(DATA, CLASS)->METHOD()>. Note that this means that |
800 | the method specified will have to perform any modifications required on the |
801 | object (like creating new state within it, and/or reblessing it in a |
802 | different package) and then return it. The client is responsible for making |
803 | sure the method can be called via the object, and that it returns a valid |
804 | object. Defaults to an empty string. |
805 | |
806 | =item $Data::Dumper::Deepcopy I<or> $I<OBJ>->Deepcopy(I<[NEWVAL]>) |
807 | |
808 | Can be set to a boolean value to enable deep copies of structures. |
809 | Cross-referencing will then only be done when absolutely essential |
810 | (i.e., to break reference cycles). Default is 0. |
811 | |
812 | =item $Data::Dumper::Quotekeys I<or> $I<OBJ>->Quotekeys(I<[NEWVAL]>) |
813 | |
814 | Can be set to a boolean value to control whether hash keys are quoted. |
815 | A false value will avoid quoting hash keys when it looks like a simple |
816 | string. Default is 1, which will always enclose hash keys in quotes. |
817 | |
818 | =item $Data::Dumper::Bless I<or> $I<OBJ>->Bless(I<[NEWVAL]>) |
819 | |
820 | Can be set to a string that specifies an alternative to the C<bless> |
821 | builtin operator used to create objects. A function with the specified |
822 | name should exist, and should accept the same arguments as the builtin. |
823 | Default is C<bless>. |
824 | |
825 | =back |
826 | |
827 | =head2 Exports |
828 | |
829 | =over 4 |
830 | |
831 | =item Dumper |
832 | |
833 | =back |
834 | |
835 | =head1 EXAMPLES |
836 | |
837 | Run these code snippets to get a quick feel for the behavior of this |
838 | module. When you are through with these examples, you may want to |
839 | add or change the various configuration variables described above, |
840 | to see their behavior. (See the testsuite in the Data::Dumper |
841 | distribution for more examples.) |
842 | |
843 | |
844 | use Data::Dumper; |
845 | |
846 | package Foo; |
847 | sub new {bless {'a' => 1, 'b' => sub { return "foo" }}, $_[0]}; |
848 | |
849 | package Fuz; # a weird REF-REF-SCALAR object |
850 | sub new {bless \($_ = \ 'fu\'z'), $_[0]}; |
851 | |
852 | package main; |
853 | $foo = Foo->new; |
854 | $fuz = Fuz->new; |
855 | $boo = [ 1, [], "abcd", \*foo, |
856 | {1 => 'a', 023 => 'b', 0x45 => 'c'}, |
857 | \\"p\q\'r", $foo, $fuz]; |
858 | |
859 | ######## |
860 | # simple usage |
861 | ######## |
862 | |
863 | $bar = eval(Dumper($boo)); |
864 | print($@) if $@; |
865 | print Dumper($boo), Dumper($bar); # pretty print (no array indices) |
866 | |
867 | $Data::Dumper::Terse = 1; # don't output names where feasible |
868 | $Data::Dumper::Indent = 0; # turn off all pretty print |
869 | print Dumper($boo), "\n"; |
870 | |
871 | $Data::Dumper::Indent = 1; # mild pretty print |
872 | print Dumper($boo); |
873 | |
874 | $Data::Dumper::Indent = 3; # pretty print with array indices |
875 | print Dumper($boo); |
876 | |
877 | $Data::Dumper::Useqq = 1; # print strings in double quotes |
878 | print Dumper($boo); |
879 | |
880 | |
881 | ######## |
882 | # recursive structures |
883 | ######## |
884 | |
885 | @c = ('c'); |
886 | $c = \@c; |
887 | $b = {}; |
888 | $a = [1, $b, $c]; |
889 | $b->{a} = $a; |
890 | $b->{b} = $a->[1]; |
891 | $b->{c} = $a->[2]; |
892 | print Data::Dumper->Dump([$a,$b,$c], [qw(a b c)]); |
893 | |
894 | |
895 | $Data::Dumper::Purity = 1; # fill in the holes for eval |
896 | print Data::Dumper->Dump([$a, $b], [qw(*a b)]); # print as @a |
897 | print Data::Dumper->Dump([$b, $a], [qw(*b a)]); # print as %b |
898 | |
899 | |
900 | $Data::Dumper::Deepcopy = 1; # avoid cross-refs |
901 | print Data::Dumper->Dump([$b, $a], [qw(*b a)]); |
902 | |
903 | |
904 | $Data::Dumper::Purity = 0; # avoid cross-refs |
905 | print Data::Dumper->Dump([$b, $a], [qw(*b a)]); |
906 | |
907 | |
908 | ######## |
909 | # object-oriented usage |
910 | ######## |
911 | |
912 | $d = Data::Dumper->new([$a,$b], [qw(a b)]); |
913 | $d->Seen({'*c' => $c}); # stash a ref without printing it |
914 | $d->Indent(3); |
915 | print $d->Dump; |
916 | $d->Reset->Purity(0); # empty the seen cache |
917 | print join "----\n", $d->Dump; |
918 | |
919 | |
920 | ######## |
921 | # persistence |
922 | ######## |
923 | |
924 | package Foo; |
925 | sub new { bless { state => 'awake' }, shift } |
926 | sub Freeze { |
927 | my $s = shift; |
928 | print STDERR "preparing to sleep\n"; |
929 | $s->{state} = 'asleep'; |
930 | return bless $s, 'Foo::ZZZ'; |
931 | } |
932 | |
933 | package Foo::ZZZ; |
934 | sub Thaw { |
935 | my $s = shift; |
936 | print STDERR "waking up\n"; |
937 | $s->{state} = 'awake'; |
938 | return bless $s, 'Foo'; |
939 | } |
940 | |
941 | package Foo; |
942 | use Data::Dumper; |
943 | $a = Foo->new; |
944 | $b = Data::Dumper->new([$a], ['c']); |
945 | $b->Freezer('Freeze'); |
946 | $b->Toaster('Thaw'); |
947 | $c = $b->Dump; |
948 | print $c; |
949 | $d = eval $c; |
950 | print Data::Dumper->Dump([$d], ['d']); |
951 | |
952 | |
953 | ######## |
954 | # symbol substitution (useful for recreating CODE refs) |
955 | ######## |
956 | |
957 | sub foo { print "foo speaking\n" } |
958 | *other = \&foo; |
959 | $bar = [ \&other ]; |
960 | $d = Data::Dumper->new([\&other,$bar],['*other','bar']); |
961 | $d->Seen({ '*foo' => \&foo }); |
962 | print $d->Dump; |
963 | |
964 | |
965 | =head1 BUGS |
966 | |
967 | Due to limitations of Perl subroutine call semantics, you cannot pass an |
968 | array or hash. Prepend it with a C<\> to pass its reference instead. This |
969 | will be remedied in time, with the arrival of prototypes in later versions |
970 | of Perl. For now, you need to use the extended usage form, and prepend the |
971 | name with a C<*> to output it as a hash or array. |
972 | |
973 | C<Data::Dumper> cheats with CODE references. If a code reference is |
974 | encountered in the structure being processed, an anonymous subroutine that |
975 | contains the string '"DUMMY"' will be inserted in its place, and a warning |
976 | will be printed if C<Purity> is set. You can C<eval> the result, but bear |
977 | in mind that the anonymous sub that gets created is just a placeholder. |
978 | Someday, perl will have a switch to cache-on-demand the string |
979 | representation of a compiled piece of code, I hope. If you have prior |
980 | knowledge of all the code refs that your data structures are likely |
981 | to have, you can use the C<Seen> method to pre-seed the internal reference |
982 | table and make the dumped output point to them, instead. See L<EXAMPLES> |
983 | above. |
984 | |
985 | The C<Useqq> flag is not honored by C<Dumpxs()> (it always outputs |
986 | strings in single quotes). |
987 | |
988 | SCALAR objects have the weirdest looking C<bless> workaround. |
989 | |
990 | |
991 | =head1 AUTHOR |
992 | |
993 | Gurusamy Sarathy gsar@umich.edu |
994 | |
995 | Copyright (c) 1996-98 Gurusamy Sarathy. All rights reserved. |
996 | This program is free software; you can redistribute it and/or |
997 | modify it under the same terms as Perl itself. |
998 | |
999 | |
1000 | =head1 VERSION |
1001 | |
7820172a |
1002 | Version 2.10 (31 Oct 1998) |
823edd99 |
1003 | |
1004 | =head1 SEE ALSO |
1005 | |
1006 | perl(1) |
1007 | |
1008 | =cut |