$ perl -le '
> print
>    m{\d{1}.\d{6}}
>    ? qq{$_: Matched}
>    : qq{$_: No match}
>    for
>       q{in 1.234567 secs},
>       q{in 12345678 secs},
>       q{in 3A987654 secs};'
in 1.234567 secs: Matched
in 12345678 secs: Matched
in 3A987654 secs: Matched
$

##</code><code>##

$ perl -le '
> print
>    m{\d{1}\.\d{6}}
>    ? qq{$_: Matched}
>    : qq{$_: No match}
>    for
>       q{in 1.234567 secs},
>       q{in 12345678 secs},
>       q{in 3A987654 secs};'
in 1.234567 secs: Matched
in 12345678 secs: No match
in 3A987654 secs: No match
$