Perl 内部结构详解 -- PerlGuts Illustrated

之前想看一下Perl的实现，无意中搜到了这篇文章，对Perl内部类型的结构解释的很清晰，推荐感兴趣的都仔细看一下，想优化的时候做到心中有数。

接下来的几篇blog将翻译这篇文档中常见类型的部分，做个记录，加深印象，同时也方便大家阅读理解。

直接命令行的方法查看：perl -MDevel::Peek -e "$a = 123; Dump $a"

简单的例子用来查看变量内部结构：

SV = RV(0xe7190) at 0xe7184  REFCNT = 1  FLAGS = (TEMP,ROK)  RV = 0x24aaa0c  SV = PVHV(0x2401c94) at 0x24aaa0c    REFCNT = 2    FLAGS = (SHAREKEYS)    ARRAY = 0x24bd47c  (0:3, 1:5)    hash quality = 150.0%    KEYS = 5    FILL = 5    MAX = 7    RITER = -1    EITER = 0x0    Elt "1" HASH = 0x806b80c9    SV = IV(0x24b7ca0) at 0x24b7ca4      REFCNT = 1      FLAGS = (IOK,pIOK)      IV = 2    Elt "3" HASH = 0xa400c7f3    SV = IV(0x24b7c80) at 0x24b7c84      REFCNT = 1      FLAGS = (IOK,pIOK)      IV = 4    Elt "7" HASH = 0xecc9d984    SV = IV(0x24b7c60) at 0x24b7c64      REFCNT = 1      FLAGS = (IOK,pIOK)      IV = 8