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Data::Dumper: handle huge inputs on 64-bit platforms
[perl5.git] / dist / Data-Dumper / Dumper.pm
CommitLineData
823edd99
GS
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
10package Data::Dumper;
11
d036e907 12BEGIN {
2415a0a2 13 $VERSION = '2.160'; # Don't forget to set version and release
3bd791fa 14} # date in POD below!
823edd99
GS
15
16#$| = 1;
17
3b825e41 18use 5.006_001;
823edd99 19require Exporter;
823edd99
GS
20require overload;
21
22use Carp;
23
907e5114
JB
24BEGIN {
25 @ISA = qw(Exporter);
26 @EXPORT = qw(Dumper);
27 @EXPORT_OK = qw(DumperX);
823edd99 28
907e5114
JB
29 # if run under miniperl, or otherwise lacking dynamic loading,
30 # XSLoader should be attempted to load, or the pure perl flag
31 # toggled on load failure.
32 eval {
3bd791fa
JK
33 require XSLoader;
34 XSLoader::load( 'Data::Dumper' );
35 1
d036e907 36 }
1e9285c2 37 or $Useperl = 1;
907e5114 38}
823edd99 39
31ac59b6
KW
40my $IS_ASCII = ord 'A' == 65;
41
823edd99 42# module vars and their defaults
907e5114 43$Indent = 2 unless defined $Indent;
7089d392 44$Trailingcomma = 0 unless defined $Trailingcomma;
907e5114
JB
45$Purity = 0 unless defined $Purity;
46$Pad = "" unless defined $Pad;
47$Varname = "VAR" unless defined $Varname;
48$Useqq = 0 unless defined $Useqq;
49$Terse = 0 unless defined $Terse;
50$Freezer = "" unless defined $Freezer;
51$Toaster = "" unless defined $Toaster;
52$Deepcopy = 0 unless defined $Deepcopy;
53$Quotekeys = 1 unless defined $Quotekeys;
54$Bless = "bless" unless defined $Bless;
55#$Expdepth = 0 unless defined $Expdepth;
56$Maxdepth = 0 unless defined $Maxdepth;
57$Pair = ' => ' unless defined $Pair;
58$Useperl = 0 unless defined $Useperl;
59$Sortkeys = 0 unless defined $Sortkeys;
60$Deparse = 0 unless defined $Deparse;
d424882c 61$Sparseseen = 0 unless defined $Sparseseen;
19be3be6 62$Maxrecurse = 1000 unless defined $Maxrecurse;
823edd99
GS
63
64#
65# expects an arrayref of values to be dumped.
66# can optionally pass an arrayref of names for the values.
67# names must have leading $ sign stripped. begin the name with *
68# to cause output of arrays and hashes rather than refs.
69#
70sub new {
71 my($c, $v, $n) = @_;
72
3bd791fa 73 croak "Usage: PACKAGE->new(ARRAYREF, [ARRAYREF])"
823edd99 74 unless (defined($v) && (ref($v) eq 'ARRAY'));
b09a1111 75 $n = [] unless (defined($n) && (ref($n) eq 'ARRAY'));
823edd99 76
3bd791fa
JK
77 my($s) = {
78 level => 0, # current recursive depth
79 indent => $Indent, # various styles of indenting
7089d392 80 trailingcomma => $Trailingcomma, # whether to add comma after last elem
3bd791fa
JK
81 pad => $Pad, # all lines prefixed by this string
82 xpad => "", # padding-per-level
83 apad => "", # added padding for hash keys n such
84 sep => "", # list separator
85 pair => $Pair, # hash key/value separator: defaults to ' => '
86 seen => {}, # local (nested) refs (id => [name, val])
87 todump => $v, # values to dump []
88 names => $n, # optional names for values []
89 varname => $Varname, # prefix to use for tagging nameless ones
90 purity => $Purity, # degree to which output is evalable
91 useqq => $Useqq, # use "" for strings (backslashitis ensues)
92 terse => $Terse, # avoid name output (where feasible)
93 freezer => $Freezer, # name of Freezer method for objects
94 toaster => $Toaster, # name of method to revive objects
436d4ccf 95 deepcopy => $Deepcopy, # do not cross-ref, except to stop recursion
3bd791fa
JK
96 quotekeys => $Quotekeys, # quote hash keys
97 'bless' => $Bless, # keyword to use for "bless"
98# expdepth => $Expdepth, # cutoff depth for explicit dumping
99 maxdepth => $Maxdepth, # depth beyond which we give up
19be3be6 100 maxrecurse => $Maxrecurse, # depth beyond which we abort
3bd791fa
JK
101 useperl => $Useperl, # use the pure Perl implementation
102 sortkeys => $Sortkeys, # flag or filter for sorting hash keys
103 deparse => $Deparse, # use B::Deparse for coderefs
104 noseen => $Sparseseen, # do not populate the seen hash unless necessary
105 };
823edd99
GS
106
107 if ($Indent > 0) {
108 $s->{xpad} = " ";
109 $s->{sep} = "\n";
110 }
111 return bless($s, $c);
112}
113
53095d08 114# Packed numeric addresses take less memory. Plus pack is faster than sprintf
e52c0e5a 115
53095d08
NC
116# Most users of current versions of Data::Dumper will be 5.008 or later.
117# Anyone on 5.6.1 and 5.6.2 upgrading will be rare (particularly judging by
118# the bug reports from users on those platforms), so for the common case avoid
119# complexity, and avoid even compiling the unneeded code.
120
121sub init_refaddr_format {
122}
123
124sub format_refaddr {
e52c0e5a
NC
125 require Scalar::Util;
126 pack "J", Scalar::Util::refaddr(shift);
53095d08
NC
127};
128
129if ($] < 5.008) {
130 eval <<'EOC' or die;
131 no warnings 'redefine';
132 my $refaddr_format;
133 sub init_refaddr_format {
134 require Config;
135 my $f = $Config::Config{uvxformat};
136 $f =~ tr/"//d;
137 $refaddr_format = "0x%" . $f;
138 }
139
140 sub format_refaddr {
141 require Scalar::Util;
142 sprintf $refaddr_format, Scalar::Util::refaddr(shift);
143 }
144
145 1
146EOC
2728842d
RGS
147}
148
823edd99
GS
149#
150# add-to or query the table of already seen references
151#
152sub Seen {
153 my($s, $g) = @_;
154 if (defined($g) && (ref($g) eq 'HASH')) {
3b5b1125 155 init_refaddr_format();
823edd99
GS
156 my($k, $v, $id);
157 while (($k, $v) = each %$g) {
3bd791fa
JK
158 if (defined $v) {
159 if (ref $v) {
160 $id = format_refaddr($v);
161 if ($k =~ /^[*](.*)$/) {
162 $k = (ref $v eq 'ARRAY') ? ( "\\\@" . $1 ) :
163 (ref $v eq 'HASH') ? ( "\\\%" . $1 ) :
164 (ref $v eq 'CODE') ? ( "\\\&" . $1 ) :
165 ( "\$" . $1 ) ;
166 }
167 elsif ($k !~ /^\$/) {
168 $k = "\$" . $k;
169 }
170 $s->{seen}{$id} = [$k, $v];
171 }
172 else {
173 carp "Only refs supported, ignoring non-ref item \$$k";
174 }
823edd99
GS
175 }
176 else {
3bd791fa 177 carp "Value of ref must be defined; ignoring undefined item \$$k";
823edd99
GS
178 }
179 }
180 return $s;
181 }
182 else {
183 return map { @$_ } values %{$s->{seen}};
184 }
185}
186
187#
188# set or query the values to be dumped
189#
190sub Values {
191 my($s, $v) = @_;
3bd791fa
JK
192 if (defined($v)) {
193 if (ref($v) eq 'ARRAY') {
194 $s->{todump} = [@$v]; # make a copy
195 return $s;
196 }
197 else {
198 croak "Argument to Values, if provided, must be array ref";
199 }
823edd99
GS
200 }
201 else {
202 return @{$s->{todump}};
203 }
204}
205
206#
207# set or query the names of the values to be dumped
208#
209sub Names {
210 my($s, $n) = @_;
3bd791fa
JK
211 if (defined($n)) {
212 if (ref($n) eq 'ARRAY') {
213 $s->{names} = [@$n]; # make a copy
214 return $s;
215 }
216 else {
217 croak "Argument to Names, if provided, must be array ref";
218 }
823edd99
GS
219 }
220 else {
221 return @{$s->{names}};
222 }
223}
224
225sub DESTROY {}
226
0f1923bd
GS
227sub Dump {
228 return &Dumpxs
31ac59b6
KW
229 unless $Data::Dumper::Useperl || (ref($_[0]) && $_[0]->{useperl})
230 || $Data::Dumper::Deparse || (ref($_[0]) && $_[0]->{deparse})
231
232 # Use pure perl version on earlier releases on EBCDIC platforms
233 || (! $IS_ASCII && $] lt 5.021_010);
0f1923bd
GS
234 return &Dumpperl;
235}
236
823edd99
GS
237#
238# dump the refs in the current dumper object.
239# expects same args as new() if called via package name.
240#
0f1923bd 241sub Dumpperl {
823edd99
GS
242 my($s) = shift;
243 my(@out, $val, $name);
244 my($i) = 0;
245 local(@post);
2728842d 246 init_refaddr_format();
823edd99
GS
247
248 $s = $s->new(@_) unless ref $s;
249
250 for $val (@{$s->{todump}}) {
823edd99
GS
251 @post = ();
252 $name = $s->{names}[$i++];
3bd791fa 253 $name = $s->_refine_name($name, $val, $i);
823edd99
GS
254
255 my $valstr;
256 {
257 local($s->{apad}) = $s->{apad};
d34e9bd9 258 $s->{apad} .= ' ' x (length($name) + 3) if $s->{indent} >= 2 and !$s->{terse};
823edd99
GS
259 $valstr = $s->_dump($val, $name);
260 }
261
262 $valstr = "$name = " . $valstr . ';' if @post or !$s->{terse};
3bd791fa 263 my $out = $s->_compose_out($valstr, \@post);
823edd99
GS
264
265 push @out, $out;
266 }
267 return wantarray ? @out : join('', @out);
268}
269
d0c214fd
AF
270# wrap string in single quotes (escaping if needed)
271sub _quote {
272 my $val = shift;
273 $val =~ s/([\\\'])/\\$1/g;
274 return "'" . $val . "'";
275}
276
d036e907
FC
277# Old Perls (5.14-) have trouble resetting vstring magic when it is no
278# longer valid.
279use constant _bad_vsmg => defined &_vstring && (_vstring(~v0)||'') eq "v0";
280
823edd99
GS
281#
282# twist, toil and turn;
283# and recurse, of course.
31a725b3
JH
284# sometimes sordidly;
285# and curse if no recourse.
823edd99
GS
286#
287sub _dump {
288 my($s, $val, $name) = @_;
3bd791fa 289 my($out, $type, $id, $sname);
823edd99 290
823edd99
GS
291 $type = ref $val;
292 $out = "";
293
294 if ($type) {
295
c5f7c514
ST
296 # Call the freezer method if it's specified and the object has the
297 # method. Trap errors and warn() instead of die()ing, like the XS
298 # implementation.
299 my $freezer = $s->{freezer};
300 if ($freezer and UNIVERSAL::can($val, $freezer)) {
301 eval { $val->$freezer() };
302 warn "WARNING(Freezer method call failed): $@" if $@;
823edd99
GS
303 }
304
2728842d 305 require Scalar::Util;
3bd791fa
JK
306 my $realpack = Scalar::Util::blessed($val);
307 my $realtype = $realpack ? Scalar::Util::reftype($val) : ref $val;
2728842d 308 $id = format_refaddr($val);
a2126434 309
3bd791fa 310 # Note: By this point $name is always defined and of non-zero length.
436d4ccf 311 # Keep a tab on it so that we do not fall into recursive pit.
3bd791fa
JK
312 if (exists $s->{seen}{$id}) {
313 if ($s->{purity} and $s->{level} > 0) {
314 $out = ($realtype eq 'HASH') ? '{}' :
315 ($realtype eq 'ARRAY') ? '[]' :
316 'do{my $o}' ;
317 push @post, $name . " = " . $s->{seen}{$id}[0];
7820172a
GS
318 }
319 else {
3bd791fa
JK
320 $out = $s->{seen}{$id}[0];
321 if ($name =~ /^([\@\%])/) {
322 my $start = $1;
323 if ($out =~ /^\\$start/) {
324 $out = substr($out, 1);
325 }
326 else {
327 $out = $start . '{' . $out . '}';
328 }
329 }
823edd99 330 }
3bd791fa
JK
331 return $out;
332 }
333 else {
334 # store our name
335 $s->{seen}{$id} = [ (
336 ($name =~ /^[@%]/)
337 ? ('\\' . $name )
338 : ($realtype eq 'CODE' and $name =~ /^[*](.*)$/)
339 ? ('\\&' . $1 )
340 : $name
341 ), $val ];
823edd99 342 }
3bd791fa 343 my $no_bless = 0;
4ab99479
YO
344 my $is_regex = 0;
345 if ( $realpack and ($] >= 5.009005 ? re::is_regexp($val) : $realpack eq 'Regexp') ) {
346 $is_regex = 1;
347 $no_bless = $realpack eq 'Regexp';
a2126434
JN
348 }
349
3bd791fa 350 # If purity is not set and maxdepth is set, then check depth:
a2126434
JN
351 # if we have reached maximum depth, return the string
352 # representation of the thing we are currently examining
3bd791fa 353 # at this depth (i.e., 'Foo=ARRAY(0xdeadbeef)').
a2126434 354 if (!$s->{purity}
3bd791fa
JK
355 and defined($s->{maxdepth})
356 and $s->{maxdepth} > 0
357 and $s->{level} >= $s->{maxdepth})
a2126434
JN
358 {
359 return qq['$val'];
360 }
361
19be3be6
TC
362 # avoid recursing infinitely [perl #122111]
363 if ($s->{maxrecurse} > 0
364 and $s->{level} >= $s->{maxrecurse}) {
365 die "Recursion limit of $s->{maxrecurse} exceeded";
366 }
367
a2126434 368 # we have a blessed ref
3bd791fa 369 my ($blesspad);
4ab99479 370 if ($realpack and !$no_bless) {
a2126434
JN
371 $out = $s->{'bless'} . '( ';
372 $blesspad = $s->{apad};
373 $s->{apad} .= ' ' if ($s->{indent} >= 2);
7894fbab
GS
374 }
375
823edd99 376 $s->{level}++;
3bd791fa 377 my $ipad = $s->{xpad} x $s->{level};
823edd99 378
4ab99479
YO
379 if ($is_regex) {
380 my $pat;
b183d514
TC
381 my $flags = "";
382 if (defined(*re::regexp_pattern{CODE})) {
383 ($pat, $flags) = re::regexp_pattern($val);
3bd791fa
JK
384 }
385 else {
386 $pat = "$val";
4ab99479 387 }
de5ef703 388 $pat =~ s <(\\.)|/> { $1 || '\\/' }ge;
b183d514 389 $out .= "qr/$pat/$flags";
4ab99479 390 }
d036e907 391 elsif ($realtype eq 'SCALAR' || $realtype eq 'REF'
3bd791fa 392 || $realtype eq 'VSTRING') {
823edd99 393 if ($realpack) {
3bd791fa 394 $out .= 'do{\\(my $o = ' . $s->_dump($$val, "\${$name}") . ')}';
823edd99
GS
395 }
396 else {
3bd791fa 397 $out .= '\\' . $s->_dump($$val, "\${$name}");
823edd99
GS
398 }
399 }
400 elsif ($realtype eq 'GLOB') {
3bd791fa 401 $out .= '\\' . $s->_dump($$val, "*{$name}");
823edd99
GS
402 }
403 elsif ($realtype eq 'ARRAY') {
a36ee16f 404 my($pad, $mname);
823edd99
GS
405 my($i) = 0;
406 $out .= ($name =~ /^\@/) ? '(' : '[';
407 $pad = $s->{sep} . $s->{pad} . $s->{apad};
3bd791fa
JK
408 ($name =~ /^\@(.*)$/) ? ($mname = "\$" . $1) :
409 # omit -> if $foo->[0]->{bar}, but not ${$foo->[0]}->{bar}
410 ($name =~ /^\\?[\%\@\*\$][^{].*[]}]$/) ? ($mname = $name) :
411 ($mname = $name . '->');
823edd99 412 $mname .= '->' if $mname =~ /^\*.+\{[A-Z]+\}$/;
a36ee16f 413 for my $v (@$val) {
3bd791fa
JK
414 $sname = $mname . '[' . $i . ']';
415 $out .= $pad . $ipad . '#' . $i
416 if $s->{indent} >= 3;
417 $out .= $pad . $ipad . $s->_dump($v, $sname);
7089d392
AC
418 $out .= ","
419 if $i++ < $#$val
420 || ($s->{trailingcomma} && $s->{indent} >= 1);
823edd99
GS
421 }
422 $out .= $pad . ($s->{xpad} x ($s->{level} - 1)) if $i;
423 $out .= ($name =~ /^\@/) ? ')' : ']';
424 }
425 elsif ($realtype eq 'HASH') {
3bd791fa 426 my ($k, $v, $pad, $lpad, $mname, $pair);
823edd99
GS
427 $out .= ($name =~ /^\%/) ? '(' : '{';
428 $pad = $s->{sep} . $s->{pad} . $s->{apad};
429 $lpad = $s->{apad};
30b4f386 430 $pair = $s->{pair};
7820172a 431 ($name =~ /^\%(.*)$/) ? ($mname = "\$" . $1) :
3bd791fa
JK
432 # omit -> if $foo->[0]->{bar}, but not ${$foo->[0]}->{bar}
433 ($name =~ /^\\?[\%\@\*\$][^{].*[]}]$/) ? ($mname = $name) :
434 ($mname = $name . '->');
823edd99 435 $mname .= '->' if $mname =~ /^\*.+\{[A-Z]+\}$/;
3bd791fa
JK
436 my $sortkeys = defined($s->{sortkeys}) ? $s->{sortkeys} : '';
437 my $keys = [];
31a725b3 438 if ($sortkeys) {
3bd791fa
JK
439 if (ref($s->{sortkeys}) eq 'CODE') {
440 $keys = $s->{sortkeys}($val);
441 unless (ref($keys) eq 'ARRAY') {
442 carp "Sortkeys subroutine did not return ARRAYREF";
443 $keys = [];
444 }
445 }
446 else {
447 $keys = [ sort keys %$val ];
448 }
31a725b3 449 }
b36d99fa
AV
450
451 # Ensure hash iterator is reset
452 keys(%$val);
453
3bd791fa 454 my $key;
31a725b3 455 while (($k, $v) = ! $sortkeys ? (each %$val) :
3bd791fa
JK
456 @$keys ? ($key = shift(@$keys), $val->{$key}) :
457 () )
31a725b3 458 {
3bd791fa 459 my $nk = $s->_dump($k, "");
5b50ddc0
TC
460
461 # _dump doesn't quote numbers of this form
462 if ($s->{quotekeys} && $nk =~ /^(?:0|-?[1-9][0-9]{0,8})\z/) {
463 $nk = $s->{useqq} ? qq("$nk") : qq('$nk');
464 }
465 elsif (!$s->{quotekeys} and $nk =~ /^[\"\']([A-Za-z_]\w*)[\"\']$/) {
466 $nk = $1
467 }
468
3bd791fa
JK
469 $sname = $mname . '{' . $nk . '}';
470 $out .= $pad . $ipad . $nk . $pair;
471
472 # temporarily alter apad
473 $s->{apad} .= (" " x (length($nk) + 4))
474 if $s->{indent} >= 2;
475 $out .= $s->_dump($val->{$k}, $sname) . ",";
476 $s->{apad} = $lpad
477 if $s->{indent} >= 2;
823edd99
GS
478 }
479 if (substr($out, -1) eq ',') {
7089d392 480 chop $out if !$s->{trailingcomma} || !$s->{indent};
3bd791fa 481 $out .= $pad . ($s->{xpad} x ($s->{level} - 1));
823edd99
GS
482 }
483 $out .= ($name =~ /^\%/) ? ')' : '}';
484 }
485 elsif ($realtype eq 'CODE') {
8e5f9a6e 486 if ($s->{deparse}) {
3bd791fa
JK
487 require B::Deparse;
488 my $sub = 'sub ' . (B::Deparse->new)->coderef2text($val);
489 $pad = $s->{sep} . $s->{pad} . $s->{apad} . $s->{xpad} x ($s->{level} - 1);
490 $sub =~ s/\n/$pad/gse;
491 $out .= $sub;
492 }
493 else {
8e5f9a6e
RGS
494 $out .= 'sub { "DUMMY" }';
495 carp "Encountered CODE ref, using dummy placeholder" if $s->{purity};
496 }
823edd99
GS
497 }
498 else {
3bd791fa 499 croak "Can't handle '$realtype' type";
823edd99 500 }
3bd791fa 501
4ab99479 502 if ($realpack and !$no_bless) { # we have a blessed ref
d0c214fd 503 $out .= ', ' . _quote($realpack) . ' )';
3bd791fa
JK
504 $out .= '->' . $s->{toaster} . '()'
505 if $s->{toaster} ne '';
823edd99
GS
506 $s->{apad} = $blesspad;
507 }
508 $s->{level}--;
823edd99
GS
509 }
510 else { # simple scalar
511
512 my $ref = \$_[1];
d036e907 513 my $v;
823edd99
GS
514 # first, catalog the scalar
515 if ($name ne '') {
2728842d 516 $id = format_refaddr($ref);
823edd99 517 if (exists $s->{seen}{$id}) {
7820172a 518 if ($s->{seen}{$id}[2]) {
3bd791fa
JK
519 $out = $s->{seen}{$id}[0];
520 #warn "[<$out]\n";
521 return "\${$out}";
522 }
823edd99
GS
523 }
524 else {
3bd791fa
JK
525 #warn "[>\\$name]\n";
526 $s->{seen}{$id} = ["\\$name", $ref];
823edd99
GS
527 }
528 }
c1205a1e
FC
529 $ref = \$val;
530 if (ref($ref) eq 'GLOB') { # glob
823edd99 531 my $name = substr($val, 1);
58cee0f7 532 if ($name =~ /^[A-Za-z_][\w:]*$/ && $name ne 'main::') {
3bd791fa
JK
533 $name =~ s/^main::/::/;
534 $sname = $name;
823edd99
GS
535 }
536 else {
3bd791fa
JK
537 $sname = $s->_dump(
538 $name eq 'main::' || $] < 5.007 && $name eq "main::\0"
539 ? ''
540 : $name,
541 "",
542 );
543 $sname = '{' . $sname . '}';
823edd99
GS
544 }
545 if ($s->{purity}) {
3bd791fa
JK
546 my $k;
547 local ($s->{level}) = 0;
548 for $k (qw(SCALAR ARRAY HASH)) {
549 my $gval = *$val{$k};
550 next unless defined $gval;
551 next if $k eq "SCALAR" && ! defined $$gval; # always there
552
553 # _dump can push into @post, so we hold our place using $postlen
554 my $postlen = scalar @post;
555 $post[$postlen] = "\*$sname = ";
556 local ($s->{apad}) = " " x length($post[$postlen]) if $s->{indent} >= 2;
557 $post[$postlen] .= $s->_dump($gval, "\*$sname\{$k\}");
558 }
823edd99
GS
559 }
560 $out .= '*' . $sname;
561 }
7820172a
GS
562 elsif (!defined($val)) {
563 $out .= "undef";
564 }
d036e907 565 elsif (defined &_vstring and $v = _vstring($val)
3bd791fa 566 and !_bad_vsmg || eval $v eq $val) {
d036e907
FC
567 $out .= $v;
568 }
569 elsif (!defined &_vstring
c1205a1e 570 and ref $ref eq 'VSTRING' || eval{Scalar::Util::isvstring($val)}) {
d036e907
FC
571 $out .= sprintf "%vd", $val;
572 }
5b50ddc0
TC
573 # \d here would treat "1\x{660}" as a safe decimal number
574 elsif ($val =~ /^(?:0|-?[1-9][0-9]{0,8})\z/) { # safe decimal number
823edd99
GS
575 $out .= $val;
576 }
3bd791fa 577 else { # string
c4cce848 578 if ($s->{useqq} or $val =~ tr/\0-\377//c) {
38a44b82 579 # Fall back to qq if there's Unicode
3bd791fa 580 $out .= qquote($val, $s->{useqq});
823edd99
GS
581 }
582 else {
d0c214fd 583 $out .= _quote($val);
823edd99
GS
584 }
585 }
586 }
7820172a
GS
587 if ($id) {
588 # if we made it this far, $id was added to seen list at current
589 # level, so remove it to get deep copies
590 if ($s->{deepcopy}) {
591 delete($s->{seen}{$id});
592 }
593 elsif ($name) {
594 $s->{seen}{$id}[2] = 1;
595 }
596 }
823edd99
GS
597 return $out;
598}
3bd791fa 599
823edd99
GS
600#
601# non-OO style of earlier version
602#
603sub Dumper {
604 return Data::Dumper->Dump([@_]);
605}
606
0f1923bd 607# compat stub
823edd99
GS
608sub DumperX {
609 return Data::Dumper->Dumpxs([@_], []);
610}
611
823edd99 612#
3bd791fa 613# reset the "seen" cache
823edd99
GS
614#
615sub Reset {
616 my($s) = shift;
617 $s->{seen} = {};
618 return $s;
619}
620
621sub Indent {
622 my($s, $v) = @_;
623 if (defined($v)) {
624 if ($v == 0) {
625 $s->{xpad} = "";
626 $s->{sep} = "";
627 }
628 else {
629 $s->{xpad} = " ";
630 $s->{sep} = "\n";
631 }
632 $s->{indent} = $v;
633 return $s;
634 }
635 else {
636 return $s->{indent};
637 }
638}
639
7089d392
AC
640sub Trailingcomma {
641 my($s, $v) = @_;
642 defined($v) ? (($s->{trailingcomma} = $v), return $s) : $s->{trailingcomma};
643}
644
30b4f386 645sub Pair {
646 my($s, $v) = @_;
647 defined($v) ? (($s->{pair} = $v), return $s) : $s->{pair};
648}
649
823edd99
GS
650sub Pad {
651 my($s, $v) = @_;
652 defined($v) ? (($s->{pad} = $v), return $s) : $s->{pad};
653}
654
655sub Varname {
656 my($s, $v) = @_;
657 defined($v) ? (($s->{varname} = $v), return $s) : $s->{varname};
658}
659
660sub Purity {
661 my($s, $v) = @_;
662 defined($v) ? (($s->{purity} = $v), return $s) : $s->{purity};
663}
664
665sub Useqq {
666 my($s, $v) = @_;
667 defined($v) ? (($s->{useqq} = $v), return $s) : $s->{useqq};
668}
669
670sub Terse {
671 my($s, $v) = @_;
672 defined($v) ? (($s->{terse} = $v), return $s) : $s->{terse};
673}
674
675sub Freezer {
676 my($s, $v) = @_;
677 defined($v) ? (($s->{freezer} = $v), return $s) : $s->{freezer};
678}
679
680sub Toaster {
681 my($s, $v) = @_;
682 defined($v) ? (($s->{toaster} = $v), return $s) : $s->{toaster};
683}
684
685sub Deepcopy {
686 my($s, $v) = @_;
687 defined($v) ? (($s->{deepcopy} = $v), return $s) : $s->{deepcopy};
688}
689
690sub Quotekeys {
691 my($s, $v) = @_;
692 defined($v) ? (($s->{quotekeys} = $v), return $s) : $s->{quotekeys};
693}
694
695sub Bless {
696 my($s, $v) = @_;
697 defined($v) ? (($s->{'bless'} = $v), return $s) : $s->{'bless'};
698}
699
a2126434
JN
700sub Maxdepth {
701 my($s, $v) = @_;
702 defined($v) ? (($s->{'maxdepth'} = $v), return $s) : $s->{'maxdepth'};
703}
704
19be3be6
TC
705sub Maxrecurse {
706 my($s, $v) = @_;
707 defined($v) ? (($s->{'maxrecurse'} = $v), return $s) : $s->{'maxrecurse'};
708}
709
31a725b3
JH
710sub Useperl {
711 my($s, $v) = @_;
712 defined($v) ? (($s->{'useperl'} = $v), return $s) : $s->{'useperl'};
713}
714
715sub Sortkeys {
716 my($s, $v) = @_;
717 defined($v) ? (($s->{'sortkeys'} = $v), return $s) : $s->{'sortkeys'};
718}
719
8e5f9a6e
RGS
720sub Deparse {
721 my($s, $v) = @_;
722 defined($v) ? (($s->{'deparse'} = $v), return $s) : $s->{'deparse'};
723}
a2126434 724
d424882c
SM
725sub Sparseseen {
726 my($s, $v) = @_;
727 defined($v) ? (($s->{'noseen'} = $v), return $s) : $s->{'noseen'};
728}
729
7820172a 730# used by qquote below
3bd791fa 731my %esc = (
7820172a
GS
732 "\a" => "\\a",
733 "\b" => "\\b",
734 "\t" => "\\t",
735 "\n" => "\\n",
736 "\f" => "\\f",
737 "\r" => "\\r",
738 "\e" => "\\e",
739);
740
31ac59b6
KW
741my $low_controls = ($IS_ASCII)
742
743 # This includes \177, because traditionally it has been
744 # output as octal, even though it isn't really a "low"
745 # control
746 ? qr/[\0-\x1f\177]/
747
748 # EBCDIC low controls.
749 : qr/[\0-\x3f]/;
750
823edd99
GS
751# put a string value in double quotes
752sub qquote {
753 local($_) = shift;
7820172a 754 s/([\\\"\@\$])/\\$1/g;
31ac59b6
KW
755
756 # This efficiently changes the high ordinal characters to \x{} if the utf8
757 # flag is on. On ASCII platforms, the high ordinals are all the
758 # non-ASCII's. On EBCDIC platforms, we don't include in these the non-ASCII
759 # controls whose ordinals are less than SPACE, excluded below by the range
760 # \0-\x3f. On ASCII platforms this range just compiles as part of :ascii:.
761 # On EBCDIC platforms, there is just one outlier high ordinal control, and
762 # it gets output as \x{}.
dc71dc59 763 my $bytes; { use bytes; $bytes = length }
31ac59b6
KW
764 s/([^[:ascii:]\0-\x3f])/sprintf("\\x{%x}",ord($1))/ge
765 if $bytes > length
7820172a 766
31ac59b6
KW
767 # The above doesn't get the EBCDIC outlier high ordinal control when
768 # the string is UTF-8 but there are no UTF-8 variant characters in it.
769 # We want that to come out as \x{} anyway. We need is_utf8() to do
770 # this.
771 || (! $IS_ASCII && $] ge 5.008_001 && utf8::is_utf8($_));
772
b8cae652 773 return qq("$_") unless /[[:^print:]]/; # fast exit if only printables
31ac59b6
KW
774
775 # Here, there is at least one non-printable to output. First, translate the
776 # escapes.
7820172a
GS
777 s/([\a\b\t\n\f\r\e])/$esc{$1}/g;
778
31ac59b6
KW
779 # no need for 3 digits in escape for octals not followed by a digit.
780 s/($low_controls)(?!\d)/'\\'.sprintf('%o',ord($1))/eg;
781
782 # But otherwise use 3 digits
783 s/($low_controls)/'\\'.sprintf('%03o',ord($1))/eg;
784
43948175 785 # all but last branch below not supported --BEHAVIOR SUBJECT TO CHANGE--
31ac59b6
KW
786 my $high = shift || "";
787 if ($high eq "iso8859") { # Doesn't escape the Latin1 printables
788 if ($IS_ASCII) {
789 s/([\200-\240])/'\\'.sprintf('%o',ord($1))/eg;
790 }
791 elsif ($] ge 5.007_003) {
792 my $high_control = utf8::unicode_to_native(0x9F);
793 s/$high_control/sprintf('\\%o',ord($1))/eg;
794 }
0407a77b 795 } elsif ($high eq "utf8") {
31ac59b6
KW
796# Some discussion of what to do here is in
797# https://rt.perl.org/Ticket/Display.html?id=113088
0407a77b
GS
798# use utf8;
799# $str =~ s/([^\040-\176])/sprintf "\\x{%04x}", ord($1)/ge;
800 } elsif ($high eq "8bit") {
801 # leave it as it is
802 } else {
31ac59b6
KW
803 s/([[:^ascii:]])/'\\'.sprintf('%03o',ord($1))/eg;
804 #s/([^\040-\176])/sprintf "\\x{%04x}", ord($1)/ge;
0407a77b 805 }
0407a77b 806
7820172a 807 return qq("$_");
823edd99
GS
808}
809
fec5e1eb
IM
810# helper sub to sort hash keys in Perl < 5.8.0 where we don't have
811# access to sortsv() from XS
812sub _sortkeys { [ sort keys %{$_[0]} ] }
813
3bd791fa
JK
814sub _refine_name {
815 my $s = shift;
816 my ($name, $val, $i) = @_;
817 if (defined $name) {
818 if ($name =~ /^[*](.*)$/) {
819 if (defined $val) {
820 $name = (ref $val eq 'ARRAY') ? ( "\@" . $1 ) :
821 (ref $val eq 'HASH') ? ( "\%" . $1 ) :
822 (ref $val eq 'CODE') ? ( "\*" . $1 ) :
823 ( "\$" . $1 ) ;
824 }
825 else {
826 $name = "\$" . $1;
827 }
828 }
829 elsif ($name !~ /^\$/) {
830 $name = "\$" . $name;
831 }
832 }
833 else { # no names provided
834 $name = "\$" . $s->{varname} . $i;
835 }
836 return $name;
837}
838
839sub _compose_out {
840 my $s = shift;
841 my ($valstr, $postref) = @_;
842 my $out = "";
843 $out .= $s->{pad} . $valstr . $s->{sep};
844 if (@{$postref}) {
845 $out .= $s->{pad} .
846 join(';' . $s->{sep} . $s->{pad}, @{$postref}) .
847 ';' .
848 $s->{sep};
849 }
850 return $out;
851}
852
823edd99
GS
8531;
854__END__
855
856=head1 NAME
857
858Data::Dumper - stringified perl data structures, suitable for both printing and C<eval>
859
823edd99
GS
860=head1 SYNOPSIS
861
862 use Data::Dumper;
863
864 # simple procedural interface
865 print Dumper($foo, $bar);
866
867 # extended usage with names
868 print Data::Dumper->Dump([$foo, $bar], [qw(foo *ary)]);
869
870 # configuration variables
871 {
82df27e1 872 local $Data::Dumper::Purity = 1;
823edd99
GS
873 eval Data::Dumper->Dump([$foo, $bar], [qw(foo *ary)]);
874 }
875
876 # OO usage
877 $d = Data::Dumper->new([$foo, $bar], [qw(foo *ary)]);
878 ...
879 print $d->Dump;
880 ...
881 $d->Purity(1)->Terse(1)->Deepcopy(1);
882 eval $d->Dump;
883
884
885=head1 DESCRIPTION
886
887Given a list of scalars or reference variables, writes out their contents in
5e603302 888perl syntax. The references can also be objects. The content of each
823edd99
GS
889variable is output in a single Perl statement. Handles self-referential
890structures correctly.
891
892The return value can be C<eval>ed to get back an identical copy of the
d22722a1
SM
893original reference structure. (Please do consider the security implications
894of eval'ing code from untrusted sources!)
823edd99
GS
895
896Any references that are the same as one of those passed in will be named
897C<$VAR>I<n> (where I<n> is a numeric suffix), and other duplicate references
898to substructures within C<$VAR>I<n> will be appropriately labeled using arrow
899notation. You can specify names for individual values to be dumped if you
900use the C<Dump()> method, or you can change the default C<$VAR> prefix to
901something else. See C<$Data::Dumper::Varname> and C<$Data::Dumper::Terse>
902below.
903
904The default output of self-referential structures can be C<eval>ed, but the
905nested references to C<$VAR>I<n> will be undefined, since a recursive
906structure cannot be constructed using one Perl statement. You should set the
907C<Purity> flag to 1 to get additional statements that will correctly fill in
fc3a748c
RGS
908these references. Moreover, if C<eval>ed when strictures are in effect,
909you need to ensure that any variables it accesses are previously declared.
823edd99
GS
910
911In the extended usage form, the references to be dumped can be given
3bd791fa 912user-specified names. If a name begins with a C<*>, the output will
823edd99
GS
913describe the dereferenced type of the supplied reference for hashes and
914arrays, and coderefs. Output of names will be avoided where possible if
915the C<Terse> flag is set.
916
917In many cases, methods that are used to set the internal state of the
918object will return the object itself, so method calls can be conveniently
919chained together.
920
921Several styles of output are possible, all controlled by setting
3bd791fa 922the C<Indent> flag. See L<Configuration Variables or Methods> below
823edd99
GS
923for details.
924
925
926=head2 Methods
927
928=over 4
929
930=item I<PACKAGE>->new(I<ARRAYREF [>, I<ARRAYREF]>)
931
932Returns a newly created C<Data::Dumper> object. The first argument is an
933anonymous array of values to be dumped. The optional second argument is an
934anonymous array of names for the values. The names need not have a leading
935C<$> sign, and must be comprised of alphanumeric characters. You can begin
936a name with a C<*> to specify that the dereferenced type must be dumped
937instead of the reference itself, for ARRAY and HASH references.
938
939The prefix specified by C<$Data::Dumper::Varname> will be used with a
940numeric suffix if the name for a value is undefined.
941
942Data::Dumper will catalog all references encountered while dumping the
943values. Cross-references (in the form of names of substructures in perl
944syntax) will be inserted at all possible points, preserving any structural
945interdependencies in the original set of values. Structure traversal is
946depth-first, and proceeds in order from the first supplied value to
947the last.
948
949=item I<$OBJ>->Dump I<or> I<PACKAGE>->Dump(I<ARRAYREF [>, I<ARRAYREF]>)
950
951Returns the stringified form of the values stored in the object (preserving
952the order in which they were supplied to C<new>), subject to the
91e74348 953configuration options below. In a list context, it returns a list
823edd99
GS
954of strings corresponding to the supplied values.
955
956The second form, for convenience, simply calls the C<new> method on its
957arguments before dumping the object immediately.
958
823edd99
GS
959=item I<$OBJ>->Seen(I<[HASHREF]>)
960
961Queries or adds to the internal table of already encountered references.
962You must use C<Reset> to explicitly clear the table if needed. Such
963references are not dumped; instead, their names are inserted wherever they
964are encountered subsequently. This is useful especially for properly
965dumping subroutine references.
966
d1be9408 967Expects an anonymous hash of name => value pairs. Same rules apply for names
823edd99 968as in C<new>. If no argument is supplied, will return the "seen" list of
91e74348 969name => value pairs, in a list context. Otherwise, returns the object
823edd99
GS
970itself.
971
972=item I<$OBJ>->Values(I<[ARRAYREF]>)
973
3bd791fa
JK
974Queries or replaces the internal array of values that will be dumped. When
975called without arguments, returns the values as a list. When called with a
976reference to an array of replacement values, returns the object itself. When
977called with any other type of argument, dies.
823edd99
GS
978
979=item I<$OBJ>->Names(I<[ARRAYREF]>)
980
981Queries or replaces the internal array of user supplied names for the values
3bd791fa
JK
982that will be dumped. When called without arguments, returns the names. When
983called with an array of replacement names, returns the object itself. If the
436d4ccf 984number of replacement names exceeds the number of values to be named, the
3bd791fa 985excess names will not be used. If the number of replacement names falls short
436d4ccf 986of the number of values to be named, the list of replacement names will be
3bd791fa
JK
987exhausted and remaining values will not be renamed. When
988called with any other type of argument, dies.
823edd99
GS
989
990=item I<$OBJ>->Reset
991
992Clears the internal table of "seen" references and returns the object
993itself.
994
995=back
996
997=head2 Functions
998
999=over 4
1000
1001=item Dumper(I<LIST>)
1002
1003Returns the stringified form of the values in the list, subject to the
1004configuration options below. The values will be named C<$VAR>I<n> in the
1005output, where I<n> is a numeric suffix. Will return a list of strings
91e74348 1006in a list context.
823edd99 1007
823edd99
GS
1008=back
1009
1010=head2 Configuration Variables or Methods
1011
1012Several configuration variables can be used to control the kind of output
1013generated when using the procedural interface. These variables are usually
1014C<local>ized in a block so that other parts of the code are not affected by
3bd791fa 1015the change.
823edd99
GS
1016
1017These variables determine the default state of the object created by calling
1018the C<new> method, but cannot be used to alter the state of the object
1019thereafter. The equivalent method names should be used instead to query
1020or set the internal state of the object.
1021
1022The method forms return the object itself when called with arguments,
1023so that they can be chained together nicely.
1024
1025=over 4
1026
28bf64cc
JH
1027=item *
1028
1029$Data::Dumper::Indent I<or> I<$OBJ>->Indent(I<[NEWVAL]>)
823edd99
GS
1030
1031Controls the style of indentation. It can be set to 0, 1, 2 or 3. Style 0
1032spews output without any newlines, indentation, or spaces between list
1033items. It is the most compact format possible that can still be called
1034valid perl. Style 1 outputs a readable form with newlines but no fancy
1035indentation (each level in the structure is simply indented by a fixed
1036amount of whitespace). Style 2 (the default) outputs a very readable form
1037which takes into account the length of hash keys (so the hash value lines
1038up). Style 3 is like style 2, but also annotates the elements of arrays
1039with their index (but the comment is on its own line, so array output
1040consumes twice the number of lines). Style 2 is the default.
1041
28bf64cc
JH
1042=item *
1043
7089d392
AC
1044$Data::Dumper::Trailingcomma I<or> I<$OBJ>->Trailingcomma(I<[NEWVAL]>)
1045
1046Controls whether a comma is added after the last element of an array or
1047hash. Even when true, no comma is added between the last element of an array
1048or hash and a closing bracket when they appear on the same line. The default
1049is false.
1050
1051=item *
1052
28bf64cc 1053$Data::Dumper::Purity I<or> I<$OBJ>->Purity(I<[NEWVAL]>)
823edd99
GS
1054
1055Controls the degree to which the output can be C<eval>ed to recreate the
1056supplied reference structures. Setting it to 1 will output additional perl
1057statements that will correctly recreate nested references. The default is
10580.
1059
28bf64cc
JH
1060=item *
1061
1062$Data::Dumper::Pad I<or> I<$OBJ>->Pad(I<[NEWVAL]>)
823edd99
GS
1063
1064Specifies the string that will be prefixed to every line of the output.
1065Empty string by default.
1066
28bf64cc
JH
1067=item *
1068
1069$Data::Dumper::Varname I<or> I<$OBJ>->Varname(I<[NEWVAL]>)
823edd99
GS
1070
1071Contains the prefix to use for tagging variable names in the output. The
1072default is "VAR".
1073
28bf64cc
JH
1074=item *
1075
1076$Data::Dumper::Useqq I<or> I<$OBJ>->Useqq(I<[NEWVAL]>)
823edd99
GS
1077
1078When set, enables the use of double quotes for representing string values.
1079Whitespace other than space will be represented as C<[\n\t\r]>, "unsafe"
1080characters will be backslashed, and unprintable characters will be output as
aef2570a 1081quoted octal integers. The default is 0.
823edd99 1082
28bf64cc
JH
1083=item *
1084
1085$Data::Dumper::Terse I<or> I<$OBJ>->Terse(I<[NEWVAL]>)
823edd99
GS
1086
1087When set, Data::Dumper will emit single, non-self-referential values as
1088atoms/terms rather than statements. This means that the C<$VAR>I<n> names
1089will be avoided where possible, but be advised that such output may not
1090always be parseable by C<eval>.
1091
28bf64cc
JH
1092=item *
1093
1094$Data::Dumper::Freezer I<or> $I<OBJ>->Freezer(I<[NEWVAL]>)
823edd99
GS
1095
1096Can be set to a method name, or to an empty string to disable the feature.
1097Data::Dumper will invoke that method via the object before attempting to
1098stringify it. This method can alter the contents of the object (if, for
1099instance, it contains data allocated from C), and even rebless it in a
1100different package. The client is responsible for making sure the specified
1101method can be called via the object, and that the object ends up containing
1102only perl data types after the method has been called. Defaults to an empty
1103string.
1104
c5f7c514
ST
1105If an object does not support the method specified (determined using
1106UNIVERSAL::can()) then the call will be skipped. If the method dies a
1107warning will be generated.
1108
28bf64cc
JH
1109=item *
1110
1111$Data::Dumper::Toaster I<or> $I<OBJ>->Toaster(I<[NEWVAL]>)
823edd99
GS
1112
1113Can be set to a method name, or to an empty string to disable the feature.
1114Data::Dumper will emit a method call for any objects that are to be dumped
8e5f9a6e 1115using the syntax C<bless(DATA, CLASS)-E<gt>METHOD()>. Note that this means that
823edd99
GS
1116the method specified will have to perform any modifications required on the
1117object (like creating new state within it, and/or reblessing it in a
1118different package) and then return it. The client is responsible for making
1119sure the method can be called via the object, and that it returns a valid
1120object. Defaults to an empty string.
1121
28bf64cc
JH
1122=item *
1123
1124$Data::Dumper::Deepcopy I<or> $I<OBJ>->Deepcopy(I<[NEWVAL]>)
823edd99
GS
1125
1126Can be set to a boolean value to enable deep copies of structures.
1127Cross-referencing will then only be done when absolutely essential
1128(i.e., to break reference cycles). Default is 0.
1129
28bf64cc
JH
1130=item *
1131
1132$Data::Dumper::Quotekeys I<or> $I<OBJ>->Quotekeys(I<[NEWVAL]>)
823edd99
GS
1133
1134Can be set to a boolean value to control whether hash keys are quoted.
3bd791fa 1135A defined false value will avoid quoting hash keys when it looks like a simple
823edd99
GS
1136string. Default is 1, which will always enclose hash keys in quotes.
1137
28bf64cc
JH
1138=item *
1139
1140$Data::Dumper::Bless I<or> $I<OBJ>->Bless(I<[NEWVAL]>)
823edd99
GS
1141
1142Can be set to a string that specifies an alternative to the C<bless>
1143builtin operator used to create objects. A function with the specified
1144name should exist, and should accept the same arguments as the builtin.
1145Default is C<bless>.
1146
28bf64cc
JH
1147=item *
1148
30b4f386 1149$Data::Dumper::Pair I<or> $I<OBJ>->Pair(I<[NEWVAL]>)
1150
1151Can be set to a string that specifies the separator between hash keys
1152and values. To dump nested hash, array and scalar values to JavaScript,
1153use: C<$Data::Dumper::Pair = ' : ';>. Implementing C<bless> in JavaScript
1154is left as an exercise for the reader.
1155A function with the specified name exists, and accepts the same arguments
1156as the builtin.
1157
1158Default is: C< =E<gt> >.
1159
1160=item *
1161
28bf64cc 1162$Data::Dumper::Maxdepth I<or> $I<OBJ>->Maxdepth(I<[NEWVAL]>)
a2126434
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1163
1164Can be set to a positive integer that specifies the depth beyond which
5e603302 1165we don't venture into a structure. Has no effect when
a2126434 1166C<Data::Dumper::Purity> is set. (Useful in debugger when we often don't
3bd791fa
JK
1167want to see more than enough). Default is 0, which means there is
1168no maximum depth.
a2126434 1169
28bf64cc
JH
1170=item *
1171
19be3be6
TC
1172$Data::Dumper::Maxrecurse I<or> $I<OBJ>->Maxrecurse(I<[NEWVAL]>)
1173
1174Can be set to a positive integer that specifies the depth beyond which
1175recursion into a structure will throw an exception. This is intended
1176as a security measure to prevent perl running out of stack space when
1177dumping an excessively deep structure. Can be set to 0 to remove the
1178limit. Default is 1000.
1179
1180=item *
1181
28bf64cc 1182$Data::Dumper::Useperl I<or> $I<OBJ>->Useperl(I<[NEWVAL]>)
31a725b3
JH
1183
1184Can be set to a boolean value which controls whether the pure Perl
1185implementation of C<Data::Dumper> is used. The C<Data::Dumper> module is
1186a dual implementation, with almost all functionality written in both
1187pure Perl and also in XS ('C'). Since the XS version is much faster, it
1188will always be used if possible. This option lets you override the
1189default behavior, usually for testing purposes only. Default is 0, which
1190means the XS implementation will be used if possible.
1191
28bf64cc
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1192=item *
1193
1194$Data::Dumper::Sortkeys I<or> $I<OBJ>->Sortkeys(I<[NEWVAL]>)
31a725b3
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1195
1196Can be set to a boolean value to control whether hash keys are dumped in
1197sorted order. A true value will cause the keys of all hashes to be
1198dumped in Perl's default sort order. Can also be set to a subroutine
1199reference which will be called for each hash that is dumped. In this
1200case C<Data::Dumper> will call the subroutine once for each hash,
1201passing it the reference of the hash. The purpose of the subroutine is
1202to return a reference to an array of the keys that will be dumped, in
1203the order that they should be dumped. Using this feature, you can
1204control both the order of the keys, and which keys are actually used. In
1205other words, this subroutine acts as a filter by which you can exclude
1206certain keys from being dumped. Default is 0, which means that hash keys
1207are not sorted.
1208
28bf64cc
JH
1209=item *
1210
1211$Data::Dumper::Deparse I<or> $I<OBJ>->Deparse(I<[NEWVAL]>)
8e5f9a6e
RGS
1212
1213Can be set to a boolean value to control whether code references are
1214turned into perl source code. If set to a true value, C<B::Deparse>
1215will be used to get the source of the code reference. Using this option
1216will force using the Perl implementation of the dumper, since the fast
1217XSUB implementation doesn't support it.
1218
1219Caution : use this option only if you know that your coderefs will be
1220properly reconstructed by C<B::Deparse>.
1221
d424882c
SM
1222=item *
1223
1224$Data::Dumper::Sparseseen I<or> $I<OBJ>->Sparseseen(I<[NEWVAL]>)
1225
1226By default, Data::Dumper builds up the "seen" hash of scalars that
1227it has encountered during serialization. This is very expensive.
1228This seen hash is necessary to support and even just detect circular
1229references. It is exposed to the user via the C<Seen()> call both
1230for writing and reading.
1231
1232If you, as a user, do not need explicit access to the "seen" hash,
1233then you can set the C<Sparseseen> option to allow Data::Dumper
1234to eschew building the "seen" hash for scalars that are known not
1235to possess more than one reference. This speeds up serialization
1236considerably if you use the XS implementation.
1237
1238Note: If you turn on C<Sparseseen>, then you must not rely on the
1239content of the seen hash since its contents will be an
1240implementation detail!
1241
823edd99
GS
1242=back
1243
1244=head2 Exports
1245
1246=over 4
1247
1248=item Dumper
1249
1250=back
1251
1252=head1 EXAMPLES
1253
1254Run these code snippets to get a quick feel for the behavior of this
1255module. When you are through with these examples, you may want to
1256add or change the various configuration variables described above,
1257to see their behavior. (See the testsuite in the Data::Dumper
1258distribution for more examples.)
1259
1260
1261 use Data::Dumper;
1262
1263 package Foo;
1264 sub new {bless {'a' => 1, 'b' => sub { return "foo" }}, $_[0]};
1265
1266 package Fuz; # a weird REF-REF-SCALAR object
1267 sub new {bless \($_ = \ 'fu\'z'), $_[0]};
1268
1269 package main;
1270 $foo = Foo->new;
1271 $fuz = Fuz->new;
1272 $boo = [ 1, [], "abcd", \*foo,
3bd791fa 1273 {1 => 'a', 023 => 'b', 0x45 => 'c'},
823edd99 1274 \\"p\q\'r", $foo, $fuz];
3cb6de81 1275
823edd99
GS
1276 ########
1277 # simple usage
1278 ########
1279
1280 $bar = eval(Dumper($boo));
1281 print($@) if $@;
1282 print Dumper($boo), Dumper($bar); # pretty print (no array indices)
1283
b877fea2
FC
1284 $Data::Dumper::Terse = 1; # don't output names where feasible
1285 $Data::Dumper::Indent = 0; # turn off all pretty print
823edd99
GS
1286 print Dumper($boo), "\n";
1287
b877fea2 1288 $Data::Dumper::Indent = 1; # mild pretty print
823edd99
GS
1289 print Dumper($boo);
1290
b877fea2 1291 $Data::Dumper::Indent = 3; # pretty print with array indices
823edd99
GS
1292 print Dumper($boo);
1293
b877fea2 1294 $Data::Dumper::Useqq = 1; # print strings in double quotes
823edd99 1295 print Dumper($boo);
3cb6de81 1296
b877fea2 1297 $Data::Dumper::Pair = " : "; # specify hash key/value separator
30b4f386 1298 print Dumper($boo);
1299
3cb6de81 1300
823edd99
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1301 ########
1302 # recursive structures
1303 ########
3cb6de81 1304
823edd99
GS
1305 @c = ('c');
1306 $c = \@c;
1307 $b = {};
1308 $a = [1, $b, $c];
1309 $b->{a} = $a;
1310 $b->{b} = $a->[1];
1311 $b->{c} = $a->[2];
1312 print Data::Dumper->Dump([$a,$b,$c], [qw(a b c)]);
3cb6de81
GS
1313
1314
823edd99
GS
1315 $Data::Dumper::Purity = 1; # fill in the holes for eval
1316 print Data::Dumper->Dump([$a, $b], [qw(*a b)]); # print as @a
1317 print Data::Dumper->Dump([$b, $a], [qw(*b a)]); # print as %b
3cb6de81
GS
1318
1319
823edd99
GS
1320 $Data::Dumper::Deepcopy = 1; # avoid cross-refs
1321 print Data::Dumper->Dump([$b, $a], [qw(*b a)]);
3cb6de81
GS
1322
1323
823edd99
GS
1324 $Data::Dumper::Purity = 0; # avoid cross-refs
1325 print Data::Dumper->Dump([$b, $a], [qw(*b a)]);
3cb6de81 1326
a2126434
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1327 ########
1328 # deep structures
1329 ########
3cb6de81 1330
a2126434
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1331 $a = "pearl";
1332 $b = [ $a ];
1333 $c = { 'b' => $b };
1334 $d = [ $c ];
1335 $e = { 'd' => $d };
1336 $f = { 'e' => $e };
1337 print Data::Dumper->Dump([$f], [qw(f)]);
1338
1339 $Data::Dumper::Maxdepth = 3; # no deeper than 3 refs down
1340 print Data::Dumper->Dump([$f], [qw(f)]);
1341
3cb6de81 1342
823edd99
GS
1343 ########
1344 # object-oriented usage
1345 ########
3cb6de81 1346
823edd99
GS
1347 $d = Data::Dumper->new([$a,$b], [qw(a b)]);
1348 $d->Seen({'*c' => $c}); # stash a ref without printing it
1349 $d->Indent(3);
1350 print $d->Dump;
1351 $d->Reset->Purity(0); # empty the seen cache
1352 print join "----\n", $d->Dump;
3cb6de81
GS
1353
1354
823edd99
GS
1355 ########
1356 # persistence
1357 ########
3cb6de81 1358
823edd99
GS
1359 package Foo;
1360 sub new { bless { state => 'awake' }, shift }
1361 sub Freeze {
1362 my $s = shift;
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JK
1363 print STDERR "preparing to sleep\n";
1364 $s->{state} = 'asleep';
1365 return bless $s, 'Foo::ZZZ';
823edd99 1366 }
3cb6de81 1367
823edd99
GS
1368 package Foo::ZZZ;
1369 sub Thaw {
1370 my $s = shift;
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JK
1371 print STDERR "waking up\n";
1372 $s->{state} = 'awake';
1373 return bless $s, 'Foo';
823edd99 1374 }
3cb6de81 1375
3bd791fa 1376 package main;
823edd99
GS
1377 use Data::Dumper;
1378 $a = Foo->new;
1379 $b = Data::Dumper->new([$a], ['c']);
1380 $b->Freezer('Freeze');
1381 $b->Toaster('Thaw');
1382 $c = $b->Dump;
1383 print $c;
1384 $d = eval $c;
1385 print Data::Dumper->Dump([$d], ['d']);
3cb6de81
GS
1386
1387
823edd99
GS
1388 ########
1389 # symbol substitution (useful for recreating CODE refs)
1390 ########
3cb6de81 1391
823edd99
GS
1392 sub foo { print "foo speaking\n" }
1393 *other = \&foo;
1394 $bar = [ \&other ];
1395 $d = Data::Dumper->new([\&other,$bar],['*other','bar']);
1396 $d->Seen({ '*foo' => \&foo });
1397 print $d->Dump;
1398
1399
31a725b3
JH
1400 ########
1401 # sorting and filtering hash keys
1402 ########
1403
1404 $Data::Dumper::Sortkeys = \&my_filter;
1405 my $foo = { map { (ord, "$_$_$_") } 'I'..'Q' };
1406 my $bar = { %$foo };
1407 my $baz = { reverse %$foo };
1408 print Dumper [ $foo, $bar, $baz ];
1409
1410 sub my_filter {
1411 my ($hash) = @_;
1412 # return an array ref containing the hash keys to dump
1413 # in the order that you want them to be dumped
1414 return [
1415 # Sort the keys of %$foo in reverse numeric order
1416 $hash eq $foo ? (sort {$b <=> $a} keys %$hash) :
1417 # Only dump the odd number keys of %$bar
1418 $hash eq $bar ? (grep {$_ % 2} keys %$hash) :
1419 # Sort keys in default order for all other hashes
1420 (sort keys %$hash)
1421 ];
1422 }
1423
823edd99
GS
1424=head1 BUGS
1425
1426Due to limitations of Perl subroutine call semantics, you cannot pass an
1427array or hash. Prepend it with a C<\> to pass its reference instead. This
8e5f9a6e
RGS
1428will be remedied in time, now that Perl has subroutine prototypes.
1429For now, you need to use the extended usage form, and prepend the
823edd99
GS
1430name with a C<*> to output it as a hash or array.
1431
1432C<Data::Dumper> cheats with CODE references. If a code reference is
8e5f9a6e
RGS
1433encountered in the structure being processed (and if you haven't set
1434the C<Deparse> flag), an anonymous subroutine that
823edd99
GS
1435contains the string '"DUMMY"' will be inserted in its place, and a warning
1436will be printed if C<Purity> is set. You can C<eval> the result, but bear
1437in mind that the anonymous sub that gets created is just a placeholder.
1438Someday, perl will have a switch to cache-on-demand the string
1439representation of a compiled piece of code, I hope. If you have prior
1440knowledge of all the code refs that your data structures are likely
1441to have, you can use the C<Seen> method to pre-seed the internal reference
00baac8f 1442table and make the dumped output point to them, instead. See L</EXAMPLES>
823edd99
GS
1443above.
1444
aef2570a
TC
1445The C<Deparse> flag makes Dump() run slower, since the XSUB
1446implementation does not support it.
823edd99
GS
1447
1448SCALAR objects have the weirdest looking C<bless> workaround.
1449
fec5e1eb
IM
1450Pure Perl version of C<Data::Dumper> escapes UTF-8 strings correctly
1451only in Perl 5.8.0 and later.
1452
504f80c1
JH
1453=head2 NOTE
1454
1455Starting from Perl 5.8.1 different runs of Perl will have different
1456ordering of hash keys. The change was done for greater security,
1457see L<perlsec/"Algorithmic Complexity Attacks">. This means that
1458different runs of Perl will have different Data::Dumper outputs if
1459the data contains hashes. If you need to have identical Data::Dumper
1460outputs from different runs of Perl, use the environment variable
1461PERL_HASH_SEED, see L<perlrun/PERL_HASH_SEED>. Using this restores
1462the old (platform-specific) ordering: an even prettier solution might
1463be to use the C<Sortkeys> filter of Data::Dumper.
823edd99
GS
1464
1465=head1 AUTHOR
1466
6e238990 1467Gurusamy Sarathy gsar@activestate.com
823edd99 1468
fbfb8de6 1469Copyright (c) 1996-2014 Gurusamy Sarathy. All rights reserved.
823edd99
GS
1470This program is free software; you can redistribute it and/or
1471modify it under the same terms as Perl itself.
1472
823edd99
GS
1473=head1 VERSION
1474
2415a0a2 1475Version 2.160 (January 12 2016)
823edd99
GS
1476
1477=head1 SEE ALSO
1478
1479perl(1)
1480
1481=cut