# Scenario 1, example of the problem: 
my $is_file_exists = 1;
my $db_path = $ST_DB_PATH.$db_name;
unless (-e $db_path) {
    print "The file doesn't exist\n";
    $is_file_exists = 0;
}

##</code><code>##

# Scenario 2, example of workaround that solves the problem: 
my $is_file_exists = 1;
my $db_path = $ST_DB_PATH.$db_name;

# Adding cat command to solve the "-e" problem
`cat $db_path > /dev/null`;

unless (-e $db_path) {
    print "The file doesn't exist\n";
    $is_file_exists = 0;
}