perl小函数

#求一个数的补码，第一个参数表示位数，第二个参数表示需要求补码的数
sub complement {
    if(@_ != 2) {
        exit(0) || die("function complement's parameter error\n");
    }
    my $bit_cnt = $_[0];
    my $temp0 = $_[1];
    my $temp1 = 0;
    my $result;
    my $i;
    if($temp0 < 0) {
        $temp0 = $temp0 * (-1);
        for($i = 0; $i < $bit_cnt; $i++) {
            $temp1 = $temp1 + (0x1 << $i);
        }
        $result = $temp1 - $temp0 + 0x1;
        return $result;
    }
    else {
        $result = $temp0;
        return $result;
    }
};
#合并任意多个的文件
sub merge_file{
    my $in_file;
    my $out_file = "merge_file.out";
    my $count;
    my $buffer;
    open(OUTFILE_HANDLE, ">", $out_file) || die("cannot open file: $out_file, error information: $!\n");
    close(OUTFILE_HANDLE);
    
    foreach $in_file (@_) {
        open(INFILE_HANDLE, $in_file) || die("cannot open file: $in_file, error information: $!\n");
        binmode(INFILE_HANDLE);
        open(OUTFILE_HANDLE, ">>", $out_file) || die("cannot open file: $out_file, error information: $!\n");
        binmode(OUTFILE_HANDLE);
        while(1) {
            $count = sysread INFILE_HANDLE, $buffer, 1;
            if($count == 0) {
                #syswrite OUTFILE_HANDLE, chr(0xa), 1;
                last;
            }
            else {
                syswrite OUTFILE_HANDLE, $buffer, 1;
            }
        }
        close(INFILE_HANDLE);
        close(OUTFILE_HANDLE);
    }
};