Perl DB_File Query Key is not working but key exist

I'm new with perl. I'm writing a little code to lookup value in db from key. If I do a loop on the %hash for keys and value : I can see my keys and my values. But, when I want to load a specific key, the value is empty.

$database_obj = tie(%db_hash, 'DB_File', $database_name,
                            O_RDONLY, 0644, $DB_HASH) ||
                 fatal_exit "Cannot open database %s: $!", $database_name;

# This work - Console display [myKey1]: {myVal1} ...
while (my ($key, $val) = each(%db_hash))
        { print "[$key]: {$val}\n"; }

# but, this doesn't work - $value is empty - I want to get myVal1
$value = $db_hash{myKey1};

db_dump show this header :

VERSION=3
format=bytevalue
type=hash
h_nelem=4098
db_pagesize=4096
HEADER=END

If anyone can help me ? Thanks in advance. Regards, Yannick

I have try to manipulate the key format with or without quote.

---

Additionnal test 1

#!/usr/bin/perl

use strict;
use warnings;

use DB_File;
use Fcntl;
use Sys::Syslog qw(:DEFAULT setlogsock);

my ($database_obj, %db_hash);
my $database_name="./mydb.db";

$database_obj = tie(%db_hash, 'DB_File', $database_name,
                            O_RDONLY, 0644, $DB_HASH) ||
                 print "Cannot open database %s: $!", $database_name;

print "DUMP ...\n";
while (my ($key, $val) = each(%db_hash))
        { print "[$key]: {$val}\n"; }


my $search="mykey.1";
print "ONLY $search\n";
my $value = $db_hash{$search};
print "Value: $value\n" unless $value;

Result:

DUMP ...
[mykey.1]: {myVal1;myVal-1}
[mykey.2]: {myval2}
ONLY mykey.1
Use of uninitialized value $value in concatenation (.) or string at test.pl line 25.
Value:

keys and values can contains . -> it seems a problem ?

---

Additionnal test 2

#!/usr/bin/perl

use strict;
use warnings;

use DB_File;
use Fcntl;
use Sys::Syslog qw(:DEFAULT setlogsock);
use Data::Dumper;
$Data::Dumper::Useqq=1;

my ($database_obj, %db_hash);
my $database_name="./mydb.db";

$database_obj = tie(%db_hash, 'DB_File', $database_name,
                            O_RDONLY, 0644, $DB_HASH) ||
                 print "Cannot open database %s: $!", $database_name;

#print "DUMP ...\n";
# while (my ($key, $val) = each(%db_hash))
#        { print "[$key]: {$val}\n"; }

print Dumper \%db_hash;

my $search="mykey.1";
print "ONLY $search\n";
my $value = $db_hash{"$search"};
print "Value: $value\n" unless $value;

result:

$VAR1 = {
          "mykey.1\0" => "myVal1;myVal-1\0",
          "mykey.2\0" => "myval2\0"
        };

Sorry for delay, but it seems that we are not in the same timezone. Data are populated with postmap

I see that my strings are terminated with \0 (null terminator ?), so I try to add it in the lookup.

#!/usr/bin/perl

use strict;
use warnings;

use DB_File;
use Fcntl;
use Sys::Syslog qw(:DEFAULT setlogsock);
use Data::Dumper;
$Data::Dumper::Useqq=1;

my ($database_obj, %db_hash);
my $database_name="./mydb.db";

$database_obj = tie(%db_hash, 'DB_File', $database_name,
                            O_RDONLY, 0644, $DB_HASH) ||
                 print "Cannot open database %s: $!", $database_name;

#print "DUMP ...\n";
# while (my ($key, $val) = each(%db_hash))
#        { print "[$key]: {$val}\n"; }

print Dumper \%db_hash;

my $search="mykey.1\0";
print "ONLY $search\n";
my $value = $db_hash{"$search"};
print "Value: $value\n" unless $value;

result :

$VAR1 = {
          "mykey.1\0" => "myVal1;myVal-1\0",
          "mykey.2\0" => "myval2\0"
        };
ONLY mykey.1

No value return so $value seems to be null.

---

Additionnal info

@clamp if I remove "unless $value" it's working. I need to add \0 at the end of the key !

As mentionned in my initial question, I'm using postmap to generate the db files.

As mentionned here : https://metacpan.org/pod/DB_File#An-Example-the-NULL-termination-problem. C program add a NULL Termination at the end of the string (key and value). Postmap is written in C so it add a NULL Terminaison.

So, my problem is due to my need to read a database generate by a C program with perl

To be able to match correctly the key, it's need to add "\0" add the end of the key

$db_hash{"$search\0"}

and not

$db_hash{"$search"}