eval {
    $data = gunzip( $gz );
1 } or {
    say "Can't unzip $file: $@";
    exit 1
};
[download]

See Bug in eval in pre-5.14 for more details.

my $gz ='';
my $data;
eval {
         $data = gunzip( $gz );
         1; 
     }
 or do {
        print "Error: $@";
        exit;
        };
print "Done";
[download]

Give me Attempt to uncompress empty string at ./aaa.pl line 10. Done; Which is prevent script from die, but do not catch a fatal error.... Thank you for link to the bug

Maybe check if $gz is an empty string and don't try to call gunzip() in that case?

I also can't reproduce your problem. eval catches the error message correctly for me with your code (amended below to show that):

use 5.012;
use warnings;
use Gzip::Faster;
my $gz="";
my $data;
eval {$data=gunzip($gz)};
if($@) {
    say qq(error: $@)
};
say "Done"
[download]

This gives me the output:

Attempt to uncompress empty string at ...
Done
[download]

Most likely the code you post is not the code you run.

my $gz = 'f';
my $data;
 eval { $data = gunzip( $gz );};
 if ($@) { say "Something wrong"; exit; };
say "done";
[download]

Produce Attempt to uncompress empty string at ./aa.pl line 11. done which mean - generate fatal error but not recognize it YES, i will check that the file is not empty before using gzip - it will be easier for now

Any idea how to catch it and process by my scripts?

The warning is there to tell you (the programmer) that you're doing something wrong. The easiest step would be to stop doing the wrong thing.

#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11128056
use warnings;

use Gzip::Faster;
my $gz = '';
my $data;
eval
  {
  local *STDERR;
  open STDERR, '>', '/dev/null';

  $data = gunzip( $gz );
  } or die "can't unzip file";
[download]

Outputs just:

can't unzip file at ./pm11128056.pl line 10.
[download]

Hi,

$@ is not set because an exception is not thrown. The module is only emitting a warning to STDERR. This is as documented.

Hope this helps!