Perl 相当于 PHP 的 print_r() 是什么？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/229168/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
What is Perl's equivalent to PHP's print_r()?
提问by Steve M
I find print_r in PHP extremely useful, but wonder if there is anything remotely equivalent in Perl?
我发现 PHP 中的 print_r 非常有用，但想知道 Perl 中是否有任何远程等效的东西？
回答by Vinko Vrsalovic
Note @tchrist recommends Data::Dumpover Data::Dumper. I wasn't aware of it, but from the looks of it, seems like it's both far easier to use and producing better looking and easier to interpret results.
注意 @tchrist 建议使用Data::Dump 而不是Data::Dumper。我不知道它，但从它的外观来看，它似乎更容易使用，并且产生更好看和更容易解释的结果。
A snippet of the examples shown in the above link.
上面链接中显示的示例片段。
use Data::Dumper;
package Foo;
sub new {bless {'a' => 1, 'b' => sub { return "foo" }}, $_[0]};
package Fuz; # a weird REF-REF-SCALAR object
sub new {bless \($_ = \ 'fu\'z'), $_[0]};
package main;
$foo = Foo->new;
$fuz = Fuz->new;
$boo = [ 1, [], "abcd", \*foo,
{1 => 'a', 023 => 'b', 0x45 => 'c'},
\"p\q\'r", $foo, $fuz];
########
# simple usage
########
$bar = eval(Dumper($boo));
print($@) if $@;
print Dumper($boo), Dumper($bar); # pretty print (no array indices)
$Data::Dumper::Terse = 1; # don't output names where feasible
$Data::Dumper::Indent = 0; # turn off all pretty print
print Dumper($boo), "\n";
$Data::Dumper::Indent = 1; # mild pretty print
print Dumper($boo);
$Data::Dumper::Indent = 3; # pretty print with array indices
print Dumper($boo);
$Data::Dumper::Useqq = 1; # print strings in double quotes
print Dumper($boo);
回答by mirod
As usually with Perl, you might prefer alternative solutions to the venerable Data::Dumper:
与 Perl 一样，您可能更喜欢古老的 Data::Dumper 的替代解决方案：
- Data::Dump::Streamerhas a terser output than Data::Dumper, and can also serialize some data better than Data::Dumper,
- YAML(or Yaml::Syck, or an other YAML module) generate the data in YAML, which is quite legible.
- Data::Dump::Streamer的输出比Data::Dumper更简洁，也能比Data::Dumper更好的序列化一些数据，
- YAML（或Yaml::Syck或其他 YAML 模块）在 YAML 中生成数据，非常清晰。
And of course with the debugger, you can display any variable with the 'x' command. I particularly like the form 'x 2 $complex_structure' where 2 (or any number) tells the debugger to display only 2 levels of nested data.
当然，使用调试器，您可以使用“x”命令显示任何变量。我特别喜欢 ' x 2 $complex_structure'形式，其中 2（或任何数字）告诉调试器只显示 2 级嵌套数据。
回答by Aristotle Pagaltzis
An alternative to Data::Dumperthat does not produce valid Perl code but instead a more skimmable format (same as the xcommand of the Perl debugger) is Dumpvalue. It also consumes a lot less memory.
一个替代数据::自卸车不产生有效的Perl代码，而是一个更skimmable格式（同xPerl调试器的命令）是Dumpvalue。它也消耗更少的内存。
As well, there is Data::Dump::Streamer, which is more accurate in various edge and corner cases than Data::Dumperis.
同样，还有Data::Dump::Streamer，它在各种边缘和角落情况下比Data::Dumper更准确。
回答by kixx
I use Data::Dump, it's output is a bit cleaner than Data::Dumper's (no $VAR1), it provides quick shortcuts and it also tries to DTRT, i.e. it will print to STDERR when called in void context and return the dump string when not.
我使用Data::Dump，它的输出比 Data::Dumper 的更清晰（没有 $VAR1），它提供快速快捷方式，它还尝试 DTRT，即在 void 上下文中调用时它将打印到 STDERR 并返回转储字符串不时。
回答by Stan James
I went looking for the same thing and found this lovely little Perl function, explicitly meant to generate results like print_r().
我去寻找同样的东西，发现了这个可爱的小 Perl 函数，明确地意味着生成像 print_r() 这样的结果。
The author of the script was asking your exact question in a forum here.
该脚本的作者在此处的论坛中询问了您的确切问题。
print objectToString($json_data);
Gives this output:
给出这个输出：
HASH {
time => 1233173875
error => 0
node => HASH {
vid => 1011
moderate => 0
field_datestring => ARRAY {
HASH {
value => August 30, 1979
}
}
field_tagged_persons => ARRAY {
HASH {
nid => undef
}
}
...and so on...
