comment on

I am trying to alias or marry 2 packages without using a loop and individually glob aliasing all the symbols in that package. If I run the nz::p1 function in an eval, it works fine. I can see nz::p1 is real and is a CV after the "*nz:: = *pz::;" line with Devel Peek. If I call nz::p1 without a eval, it errors out with

Use of uninitialized value in subroutine entry at pkgalias.pl line 28.
Undefined subroutine & called at pkgalias.pl line 28.
[download]

The code is

use strict;
use warnings;
use Data::Dumper;
use Devel::Peek;

package pz;
sub p1 {
    return 1;
}
sub p2 {
    return 2;
}
package main;
print "pz is".Dumper(\%pz::);
print "nz is".Dumper(\%nz::);
print "before alias\n";
*nz:: = *pz::;
print "after alias\n";
print "nz is".Dumper(\%nz::);
warn("dumping PZ\n");
Dump(\%pz::);
warn("dumping NZ\n");
Dump(\%nz::);
#eval "print nz::p1();";
#if($@) {
#    die $@;
#}
print nz::p1();
print "after nz::p1() run\n";
[download]

Whats going on?

My output of the script

pz is$VAR1 = {
          "p1" => *pz::p1,
          "p2" => *pz::p2
        };
nz is$VAR1 = {
          "p1" => *nz::p1
        };
before alias
after alias
nz is$VAR1 = {
          "p1" => *pz::p1,
          "p2" => *pz::p2
        };
dumping PZ
SV = IV(0x8ec8d8) at 0x8ec8dc
  REFCNT = 1
  FLAGS = (TEMP,ROK)
  RV = 0x829fdc
  SV = PVHV(0x39ca04) at 0x829fdc
    REFCNT = 2
    FLAGS = (OOK,SHAREKEYS)
    ARRAY = 0x85d9bc  (0:6, 1:2)
    hash quality = 125.0%
    KEYS = 2
    FILL = 2
    MAX = 7
    RITER = -1
    EITER = 0x0
    NAME = "pz"
    BACKREFS = 0x8dad74
    SV = PVAV(0x398c04) at 0x8dad74
      REFCNT = 2
      FLAGS = ()
      ARRAY = 0x839154
      FILL = 1
      MAX = 3
      ARYLEN = 0x0
      FLAGS = ()
      Elt No. 0
      SV = PVGV(0x8e6f14) at 0x829fcc
        REFCNT = 1
        FLAGS = (MULTI)
        NAME = "p1"
        NAMELEN = 2
        GvSTASH = 0x829fdc      "pz"
        GP = 0x8355d4
          SV = 0x0
          REFCNT = 1
          IO = 0x0
          FORM = 0x0
          AV = 0x0
          HV = 0x0
          CV = 0x829f7c
          CVGEN = 0x0
          LINE = 9
          FILE = "pkgalias.pl"
          FLAGS = 0x2
          EGV = 0x829fcc        "p1"
      Elt No. 1
      SV = PVGV(0x8e6f34) at 0x84550c
        REFCNT = 1
        FLAGS = (MULTI)
        NAME = "p2"
        NAMELEN = 2
        GvSTASH = 0x829fdc      "pz"
        GP = 0x8356a4
          SV = 0x0
          REFCNT = 1
          IO = 0x0
          FORM = 0x0
          AV = 0x0
          HV = 0x0
          CV = 0x8daf44
          CVGEN = 0x0
          LINE = 12
          FILE = "pkgalias.pl"
          FLAGS = 0x2
          EGV = 0x84550c        "p2"
    MRO_WHICH = "dfs" (0x281f7560)
    CACHE_GEN = 0x1
    PKG_GEN = 0x1b
    Elt "p2" HASH = 0xe8474e38
    SV = PVGV(0x8e6f34) at 0x84550c
      REFCNT = 1
      FLAGS = (MULTI)
      NAME = "p2"
      NAMELEN = 2
      GvSTASH = 0x829fdc        "pz"
      GP = 0x8356a4
        SV = 0x0
        REFCNT = 1
        IO = 0x0
        FORM = 0x0
        AV = 0x0
        HV = 0x0
        CV = 0x8daf44
        CVGEN = 0x0
        LINE = 12
        FILE = "pkgalias.pl"
        FLAGS = 0x2
        EGV = 0x84550c  "p2"
    Elt "p1" HASH = 0xf4b56714
    SV = PVGV(0x8e6f14) at 0x829fcc
      REFCNT = 1
      FLAGS = (MULTI)
      NAME = "p1"
      NAMELEN = 2
      GvSTASH = 0x829fdc        "pz"
      GP = 0x8355d4
        SV = 0x0
        REFCNT = 1
        IO = 0x0
        FORM = 0x0
        AV = 0x0
        HV = 0x0
        CV = 0x829f7c
        CVGEN = 0x0
        LINE = 9
        FILE = "pkgalias.pl"
        FLAGS = 0x2
        EGV = 0x829fcc  "p1"
dumping NZ
SV = IV(0x8ec8d8) at 0x8ec8dc
  REFCNT = 1
  FLAGS = (TEMP,ROK)
  RV = 0x829fdc
  SV = PVHV(0x39ca04) at 0x829fdc
    REFCNT = 2
    FLAGS = (OOK,SHAREKEYS)
    ARRAY = 0x85d9bc  (0:6, 1:2)
    hash quality = 125.0%
    KEYS = 2
    FILL = 2
    MAX = 7
    RITER = -1
    EITER = 0x0
    NAME = "pz"
    BACKREFS = 0x8dad74
    SV = PVAV(0x398c04) at 0x8dad74
      REFCNT = 2
      FLAGS = ()
      ARRAY = 0x839154
      FILL = 1
      MAX = 3
      ARYLEN = 0x0
      FLAGS = ()
      Elt No. 0
      SV = PVGV(0x8e6f14) at 0x829fcc
        REFCNT = 1
        FLAGS = (MULTI)
        NAME = "p1"
        NAMELEN = 2
        GvSTASH = 0x829fdc      "pz"
        GP = 0x8355d4
          SV = 0x0
          REFCNT = 1
          IO = 0x0
          FORM = 0x0
          AV = 0x0
          HV = 0x0
          CV = 0x829f7c
          CVGEN = 0x0
          LINE = 9
          FILE = "pkgalias.pl"
          FLAGS = 0x2
          EGV = 0x829fcc        "p1"
      Elt No. 1
      SV = PVGV(0x8e6f34) at 0x84550c
        REFCNT = 1
        FLAGS = (MULTI)
        NAME = "p2"
        NAMELEN = 2
        GvSTASH = 0x829fdc      "pz"
        GP = 0x8356a4
          SV = 0x0
          REFCNT = 1
          IO = 0x0
          FORM = 0x0
          AV = 0x0
          HV = 0x0
          CV = 0x8daf44
          CVGEN = 0x0
          LINE = 12
          FILE = "pkgalias.pl"
          FLAGS = 0x2
          EGV = 0x84550c        "p2"
    MRO_WHICH = "dfs" (0x281f7560)
    CACHE_GEN = 0x1
    PKG_GEN = 0x1b
    Elt "p2" HASH = 0xe8474e38
    SV = PVGV(0x8e6f34) at 0x84550c
      REFCNT = 1
      FLAGS = (MULTI)
      NAME = "p2"
      NAMELEN = 2
      GvSTASH = 0x829fdc        "pz"
      GP = 0x8356a4
        SV = 0x0
        REFCNT = 1
        IO = 0x0
        FORM = 0x0
        AV = 0x0
        HV = 0x0
        CV = 0x8daf44
        CVGEN = 0x0
        LINE = 12
        FILE = "pkgalias.pl"
        FLAGS = 0x2
        EGV = 0x84550c  "p2"
    Elt "p1" HASH = 0xf4b56714
    SV = PVGV(0x8e6f14) at 0x829fcc
      REFCNT = 1
      FLAGS = (MULTI)
      NAME = "p1"
      NAMELEN = 2
      GvSTASH = 0x829fdc        "pz"
      GP = 0x8355d4
        SV = 0x0
        REFCNT = 1
        IO = 0x0
        FORM = 0x0
        AV = 0x0
        HV = 0x0
        CV = 0x829f7c
        CVGEN = 0x0
        LINE = 9
        FILE = "pkgalias.pl"
        FLAGS = 0x2
        EGV = 0x829fcc  "p1"
Use of uninitialized value in subroutine entry at pkgalias.pl line 28.
Undefined subroutine & called at pkgalias.pl line 28.
[download]

In reply to package aliasing by bulk88

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