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I am looking for best, easiest way to do something like:
$var1="value";
bunch of code.....
**print allVariablesAndTheirValuesCurrentlyDefined;**
404
Perl | defined() FunctionDefined() in Perl returns true if the provided variable 'VAR' has a value other than the undef value, or it checks the value of $_ if VAR is not specified. This can be used with many functions to detect for the failure of operation since they return undef if there was a problem.
@ is used for an array. In a subroutine or when you call a function in Perl, you may pass the parameter list. In that case, @_ is can be used to pass the parameter list to the function: sub Average{ # Get total number of arguments passed. $ n = scalar(@_); $sum = 0; foreach $item (@_){ # foreach is like for loop...
The most commonly used special variable is $_, which contains the default input and pattern-searching string. For example, in the following lines − #!/usr/bin/perl foreach ('hickory','dickory','doc') { print $_; print "\n"; }
The variables are shown ordered by the "distance" between the subsystem which reported the error and the Perl process...$@ is set if the string to be eval-ed did not compile (this may happen if open or close were imported with bad prototypes), or if Perl code executed during evaluation die()d.
Package variables? Lexical variables?
Package variables can be looked up via the symbol table. Try Devel::Symdump:
#!/path/to/perl
use Devel::Symdump;
package example;
$var = "value";
@var = ("value1", "value2");
%var = ("key1" => "value1", "key2" => "value2");
my $obj = Devel::Symdump->new('example');
print $obj->as_string();
Lexical variables are a little tricker, you won't find them in the symbol table. They can be looked up via the 'scratchpad' that belongs to the block of code they're defined in. Try PadWalker:
#!/path/to/perl
use strict;
use warnings;
use Data::Dumper;
use PadWalker qw(peek_my);
my $var = "value";
my @var = ("value1", "value2");
my %var = ("key1" => "value1", "key2" => "value2");
my $hash_ref = peek_my(0);
print Dumper($hash_ref);
The global symbol table is %main::, so you can get global variables from there. However, each entry is a typeglob which can hold multiple values, e.g., $x, @x, %x, etc, so you need to check for each data type. You can find code that does this here. The comments on that page might help you find other solutions for non-global variables (like lexical variables declared with "my").
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