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B::Showlex(3)          Perl Programmers Reference Guide          B::Showlex(3)

       B::Showlex - Show lexical variables used in functions or files

               perl -MO=Showlex[,-OPTIONS][,SUBROUTINE]

       When a comma-separated list of subroutine names is given as options, Showlex prints the lexical variables used
       in those subroutines.  Otherwise, it prints the file-scope lexicals in the file.

       Traditional form:

        $ perl -MO=Showlex -e 'my ($i,$j,$k)=(1,"foo")'
        Pad of lexical names for comppadlist has 4 entries
        0: SPECIAL #1 &PL_sv_undef
        1: PVNV (0x9db0fb0) $i
        2: PVNV (0x9db0f38) $j
        3: PVNV (0x9db0f50) $k
        Pad of lexical values for comppadlist has 5 entries
        0: SPECIAL #1 &PL_sv_undef
        1: NULL (0x9da4234)
        2: NULL (0x9db0f2c)
        3: NULL (0x9db0f44)
        4: NULL (0x9da4264)
        -e syntax OK

       New-style form:

        $ perl -MO=Showlex,-newlex -e 'my ($i,$j,$k)=(1,"foo")'
        main Pad has 4 entries
        0: SPECIAL #1 &PL_sv_undef
        1: PVNV (0xa0c4fb8) "$i" = NULL (0xa0b8234)
        2: PVNV (0xa0c4f40) "$j" = NULL (0xa0c4f34)
        3: PVNV (0xa0c4f58) "$k" = NULL (0xa0c4f4c)
        -e syntax OK

       New form, no specials, outside O framework:

        $ perl -MB::Showlex -e \
           'my ($i,$j,$k)=(1,"foo"); B::Showlex::compile(-newlex,-nosp)->()'
        main Pad has 4 entries
        1: PVNV (0x998ffb0) "$i" = IV (0x9983234) 1
        2: PVNV (0x998ff68) "$j" = PV (0x998ff5c) "foo"
        3: PVNV (0x998ff80) "$k" = NULL (0x998ff74)

       Note that this example shows the values of the lexicals, whereas the other examples did not (as they're com-
       pile-time only).


       The "-newlex" option produces a more readable "name => value" format, and is shown in the second example above.

       The "-nosp" option eliminates reporting of SPECIALs, such as "0: SPECIAL #1 &PL_sv_undef" above.  Reporting of
       SPECIALs can sometimes overwhelm your declared lexicals.

       "B::Showlex" can also be used outside of the O framework, as in the third example.  See "B::Concise" for a
       fuller explanation of reasons.

       Some of the reported info, such as hex addresses, is not particularly valuable.  Other information would be
       more useful for the typical programmer, such as line-numbers, pad-slot reuses, etc..  Given this, -newlex isnt
       a particularly good flag-name.

       Malcolm Beattie, ""

perl v5.8.8                       2001-09-21                     B::Showlex(3)