Is there a way to get the Perl interpreter to list all the global variables in a pl file? - perl

Question

I have a huge system that I'm converting from a cgi to a daemon and I need to find all the variables that end up being global (as in not declared with my $...)
They are probably intended to be scoped locally, but in perl if you accidentally forget, it doesn't care, but now I do.
I gotta figure the perl interpreter can tell the difference, so is there a way to get it to tell me? I could go through all the code by hand, looking for declarations, but there thousands and thousands and thousands of lines of code in this system.

Answer 1

perldoc strict will show all variables not declared with my:
$ perl -Mstrict=vars -c -e '$x=5; my $y=7; $z=6;'
Global symbol "$x" requires explicit package name at -e line 1.
Global symbol "$z" requires explicit package name at -e line 1.
-e had compilation errors.
The same thing with a list of files:
$ perl -Mstrict=vars -c *.pl
Here is another way using perldoc B::Xref
$ perl -MO=Xref -e '$x=5; my $y=7; $z=6;'
... lots of verbose output
Subroutine (main)
Package (lexical)
$y i1
Package main
$x 1
$z 1

Answer 2

With the PadWalker Module you can see all variables in a specific scope. You can see variables declared with "my" and "our".
You should still use "use strict" but using "use strict" does not show you global variables that you declare as global.
For example this example still has a global variable and strict does not do anything
#!/usr/bin/env perl
use strict;
use warnings;
our $foo;
With PadWalker you can use something like this.
#!/usr/bin/env perl
use strict;
use warnings;
use DDP;
use PadWalker qw(peek_our);
our $var;
print p peek_our(0);
The output is
\ {
$var \ undef
}
Sure, you only should use PadWalker for Debugging.