Re: [coreutils] [PATCH] head: optionally indicate underrun of set limit

[Pádraig Brady]

On 24/11/10 16:34, Pádraig Brady wrote:
> On 23/11/10 16:34, Pádraig Brady wrote:
>> On 23/11/10 16:24, Stefan Tomanek wrote:
>>> Dies schrieb Stefan Tomanek (address@hidden):
>>>
>>>> It is often convinient to detect whether head has in fact printed the
>>>> requested number of lines or if EOF was reached before reaching that
>>>> point. This patch adds the option --indicate-underrun, which makes
>>>> "head" exit with a status of 4 instead of 0 if no more data could be
>>>> read from its input.
>>>
>>> Any thoughts about this change? It's a rather small patch, but would
>>> be quite useful (at least for me).

Note the above use case is now supported with `split --filter`
http://git.sv.gnu.org/gitweb/?p=coreutils.git;a=commit;h=a09d9e5b
(Note currently the number of chunks is limited by --suffix-length).

> The following addresses both issues and
> also uses existing coreutils functionality:
> 
> process_part() { echo processing $(wc -c) bytes; }
> while true; do
>   c=$(od -tx1 -An -N1)
>   test "$c" || break
>   c=$(echo $c) #strip leading ' '
>   { printf "\x$c"; head -c9; } | process_part
> done

BTW I previously created a script with the above,
since it seems so useful. So you can use this for older systems:
https://github.com/pixelb/scripts/commits/master/scripts/split_to

cheers,
Pádraig.