Consider:
$ perl -MDevel::Peek -e 'my $x; Dump($x);'
SV = NULL(0x0) at 0x9c90cdc
REFCNT = 1
FLAGS = (PADBUSY,PADMY)
$ perl -MDevel::Peek -e 'my $x = 10; Dump($x);'
SV = IV(0x8a5a9b0) at 0x8a3ecdc
REFCNT = 1
FLAGS = (PADBUSY,PADMY,IOK,pIOK)
IV = 10
[ian@alula ~]$ perl -MDevel::Peek -e 'my $x = 10; Dump(\$x);'
SV = RV(0x809d158) at 0x8074c28
REFCNT = 1
FLAGS = (TEMP,ROK)
RV = 0x8074cdc
SV = IV(0x80909b0) at 0x8074cdc
REFCNT = 2
FLAGS = (PADBUSY,PADMY,IOK,pIOK)
IV = 10
What are all the addresses?
perldoc Devel::Peek doesn't say.
Every value has data stored in a structure 'struct sv'. Dump reports the address where this structure is located in memory as "at 0xXXXXXXXX". For example, in
SV = IV(0x8a5a9b0) at 0x8a3ecdc
The 'struct sv' for this SV is located at 0x8a3ecdc.
Most values (all but NULL values) also have data stored in a second, type specific structure. The 'struct sv' includes a pointer to this secondary structure. Dump reports the address where this secondary structure is located in memory in parentheses after the type of the value. For example, in
SV = IV(0x8a5a9b0) at 0x8a3ecdc
The type of the value is IV (which determines the type of the secondary structure) and the secondary structure is located at 0x8a5a9b0.
