Showing implicit variables?

szabgab has asked for the wisdom of the Perl Monks concerning the following question:

Is there any way to show the implicit variables in a code? Something that would take the following code:

my $filename = shift;

if ($line = /something/) {
}

foreach (@arr) {
   if (/abc/) {
      print;
   }
}

sub foo {
   my $x = shift;
}
[download]

And turn it to something like this:

my $filename = shift @ARGV;

if ($line = $_ =~ /something/) {
}

foreach $_ (@arr) {
   if ($_ =~ /abc/) {
      print $_;
   }
}


sub foo {
   my $x = shift @_;
}
[download]

I looked at B::Deparse but I could not convince it.

Comment on Showing implicit variables? Select or Download Code

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Re: Showing implicit variables? by toolic (Bishop) on Feb 27, 2009 at 18:39 UTC
B::Deparse does a pretty good job for me: `$ cat ./746989.pl my $filename = shift; if ($line = /something/) { } foreach (@arr) { if (/abc/) { print; } } sub foo { my $x = shift; } $ $ perl -MO=Deparse ./746989.pl my $filename = shift @ARGV; if ($line = /something/) { (); } foreach $_ (@arr) { if (/abc/) { print $_; } } sub foo { my $x = shift @_; } ./746989.pl syntax OK $ $ perl -v This is perl, v5.8.5 built for x86_64-linux-thread-multi` [download] Did you really mean `$line =~ /something/`?	[reply] [d/l] [select]
Re^2: Showing implicit variables? by szabgab (Priest) on Feb 27, 2009 at 23:15 UTC
Oh this is funny. The original question I wanted to post was only about this code: `if ($line = /something/) { }` [download] that I checked with B::Deparse and which did not show the implicit use of $_. The other examples (the implicit use of @_ and @ARGV) I added only to the post and did not test it. I should have done it before posting. So yes, those work for me as well but the one I originally wanted does not work. My intention was to ask about the various places where implicit variables are used. As I can see B::Deparse shows @_ and @ARGV but does not show the use of $_. So let's see if there is a tool that can show the $_ where it is used implicitly?	[reply] [d/l]