Re^2: backslash found where operator expected at

Sorry for hijacking the thread, my issue is on the SES::call_ses side. If I shift $self I get an error about an empty hash for %$opts, if I don't shift $self it works. This works:

sub call_ses {
    my $params = shift;
    my $opts = shift;

    %opts = %$opts;
    %params = %$params;

    my $endpoint_name = $endpoint;
}
[download]

This doesn't:

sub call_ses {

    my $self = shift;

    my $params = shift;
    my $opts   = shift;

    %opts   = %$opts;  <-- Line 559
    %params = %$params;

   my $endpoint_name = $self->AWS_endpoint;

}
[download]

Can't use an undefined value as a HASH reference at
        /usr/share/perl5/vendor_perl/SES.pm line 559 (#1)
    (F) A value used as either a hard reference or a symbolic referenc
+e must
    be a defined value.  This helps to delurk some insidious errors.

Uncaught exception from user code:
        Can't use an undefined value as a HASH reference at /usr/share
+/perl5/vendor_perl/SES.pm line 559.
        SES::call_ses('HASH(0x243cc00)', 'HASH(0x26a2138)') called at 
+/opt/aws/apitools/ses/bin/ses-get-stats.pl line 168
[download]

Should I abandon $self and just call the subs like I did in the working version? Thanks to the Monastery for all the years of saving my butt as I stumbled through PERL.

Comment on Re^2: backslash found where operator expected at Select or Download Code

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Re^3: backslash found where operator expected at by haj (Vicar) on May 06, 2021 at 21:33 UTC
`$self` as the first parameter of a subroutine is required if - and only if - the subroutine is called as an object or class method, and the name "self" is just a convention for the object or class the method operates on. You did not provide the code how you're calling `call_ses` and the only reference I found for your module is that aws-apitools have been deprecated as of 2015. Perhaps you might want to have a look for CPAN modules which provide an interface to SES, like e.g. Net::AWS::SES or Paws::SES?	[reply]
Re^4: backslash found where operator expected at by jmc (Initiate) on May 06, 2021 at 22:05 UTC
Apologies, I should have noted the code being used to call call_ses is the same code as in the original post. I am looking at modules but rewriting this isn't really an option, it's a legacy system that is failing now due to the AWS signature version change from 3 to 4. I'm just trying to get it to send the Signature V4 header instead of the V3.	[reply]
Re^3: backslash found where operator expected at by AnomalousMonk (Archbishop) on May 06, 2021 at 21:58 UTC
Further to haj's reply ... According to the code examples posted so far in this thread, `SES::call_ses` does not appear to be a method of the `SES` class, so assigning to a `$self` variable, which is, by convention, usually used to denote an object reference to or the class name of a class method, makes no sense. In the invocation `my ($response_code, $response_content) = SES::call_ses \%params, \%opts;` `\%params` is not a bless-ed reference (i.e., an object reference) of any kind, so don't treat it as such in a call to `$self->AWS_endpoint` in the `sub call_ses { my $self = shift; ... my $endpoint_name = $self->AWS_endpoint; }` [download] function. `SES::call_ses` seems to be an ordinary subroutine defined in the `SES` package. This subroutine does not seem to be exported, so it must be invoked via the fully-qualified `SES::call_ses` syntax. According to the error message, this subroutine was called with two arguments, so shifting three arguments off of the `@_` argument array will leave someone holding an undefined bag. Don't do that. Give a man a fish: `<%-{-{-{-<`	[reply] [d/l] [select]
Re^4: backslash found where operator expected at by jmc (Initiate) on May 06, 2021 at 22:11 UTC
Thanks Haj for the breakdown.	[reply]
Re^3: backslash found where operator expected at by Anonymous Monk on May 07, 2021 at 15:03 UTC
Thanks to the Monastery for all the years of saving my butt Welcome back, jmccall! ;-)	[reply]