On Thu, Jun 21, 2018 at 3:57 AM, Maximilian Pichler
<maxim.pich...@gmail.com> wrote:
> On Thu, Jun 21, 2018 at 9:48 AM, Otto Moerbeek <o...@drijf.net> wrote:
>>> On Thu, Jun 21, 2018 at 12:11:52AM +0200, Maximilian Pichler wrote:
>>> > I'm just wondering what these other utilities might be.
>>>
>>> hexdump -v -n 1234567 -e '"%c"'
>
> Speed-wise this is roughly on par with 'dd bs=1'.
>
>>> If the input doesn't contain backslashes (or something else, tr(1))
>>>
>>>   vis -aoF6 | head -n 1234567 | unvis
>
> Backslashes exist. :)
>
>> Variation that buffers the writes:
>>
>>         dd ibs=1 count=n
>
> Nice, this is about three time as fast as bs=1. Both are much slower
> than 'ghead -c'.
>


Reads buffered the first 5 chars from file:

$ cat file | perl -ne 'BEGIN { $/ = \1 } print if $. <= 5; exit 0 if $. == 5'

maetel$ kdump  | grep read\(0
 43509 perl     CALL  read(0,0xc9e9996f000,0x2000)
maetel$
maetel$ kdump  | grep write\(1
 43509 perl     CALL  write(1,0xc9e0c6c5000,0x5)
maetel$

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