Страницы справочника OS X

Эта страница руководства для  версии 10.9 Mac OS X

Читать страницы руководства

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



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

SYNOPSIS
               perl -MO=Showlex[,-OPTIONS][,SUBROUTINE] foo.pl

DESCRIPTION
       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.

EXAMPLES
       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 compile-time only).

   OPTIONS
       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.

SEE ALSO
       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.

TODO
       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.

AUTHOR
       Malcolm Beattie, "mbeattie@sable.ox.ac.uk"



perl v5.16.2                                     2012-10-11                                  B::Showlex(3pm)