Maybe your input file (file.properties) is not what you think it is. Show use a few lines of it.

This works for me:

use warnings;
use strict;

my %o;
while (<DATA>) {
    $o{$1}=$2 while m/(\S+)=(\S+)/g;
    print "$1 and $2\n";
    
}

__DATA__
name=ant
password=gilly
level=5
[download]

Prints:

name and ant
password and gilly
level and 5
[download]

See also:

• use strict and warnings
• Basic debugging checklist