B::Showlex - Show lexical variables used in functions or files
perl -MO=Showlex[,-OPTIONS][,SUBROUTINE] foo.pl
Perl Programmers Reference Guide B::Showlex(3) 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: (0x8caea4) undef 1: (0x9db0fb0) $i 2: (0x9db0f38) $j 3: (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,$k)=(1,"foo")' main Pad has 4 entries 0: (0x8caea4) undef 1: (0xa0c4fb8) "$i" = NULL (0xa0b8234) 2: (0xa0c4f40) "$j" = NULL (0xa0c4f34) 3: (0xa0c4f58) "$k" = NULL (0xa0c4f4c) -e syntax OK New form, no specials, outside O framework: $ perl -MB::Showlex -e \ 'my ($i,$j,$k)=(1,"foo"); B::Showlex::compile(-newlex,-nosp)->()' main Pad has 4 entries 1: (0x998ffb0) "$i" = IV (0x9983234) 1 2: (0x998ff68) "$j" = PV (0x998ff5c) "foo" 3: (0x998ff80) "$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. ATTRIBUTES See attributes(7) for descriptions of the following attributes: +---------------+-----------------------+ |ATTRIBUTE TYPE | ATTRIBUTE VALUE | +---------------+-----------------------+ |Availability | runtime/perl-532 | +---------------+-----------------------+ |Stability | Pass-through volatile | +---------------+-----------------------+ 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 is not a particularly good flag-name. AUTHOR Malcolm Beattie, "mbeattie@sable.ox.ac.uk" NOTES Source code for open source software components in Oracle Solaris can be found at https://www.oracle.com/downloads/opensource/solaris-source- code-downloads.html. This software was built from source available at https://github.com/oracle/solaris-userland. The original community source was downloaded from http://www.cpan.org/src/5.0/perl-5.32.0.tar.gz. Further information about this software can be found on the open source community website at https://www.perl.org/. perl v5.32.0 2020-06-14 B::Showlex(3)