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FREEMAIL_ENVFROM(0.00)[gmail.com]; TO_DN_SOME(0.00)[] X-Rspamd-Queue-Id: 4Qcmcs4bVlz4CN2 X-Spamd-Bar: -- X-ThisMailContainsUnwantedMimeParts: N --00000000000033603105fda9e4c9 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Thu, Jun 8, 2023 at 10:55=E2=80=AFPM Aryeh Friedman wrote: > On Thu, Jun 8, 2023 at 10:32=E2=80=AFPM Paul Procacci wrote: > > > > > > > > On Thu, Jun 8, 2023 at 9:22=E2=80=AFPM Aryeh Friedman > wrote: > >> > >> On Thu, Jun 8, 2023 at 6:37=E2=80=AFPM Dr. Nikolaus Klepp > wrote: > >> > > >> > Anno domini 2023 Thu, 8 Jun 17:22:38 -0400 > >> > Aryeh Friedman scripsit: > >> > > On Thu, Jun 8, 2023 at 2:39=E2=80=AFPM Dr. Nikolaus Klepp > wrote: > >> > > > > >> > > > Anno domini 2023 Thu, 8 Jun 14:01:19 -0400 > >> > > > Aryeh Friedman scripsit: > >> > > > > Under Java stdin (System.in) is a buffered stream not sent to > the > >> > > > > application until return is pressed. But, Java can read from > >> > > > > files/sockets and other generic InputStreams unbuffered. So = I > was > >> > > > > wondering if there is a command that will make stdin go to a > file so > >> > > > > that Java can open that file and read it unbuffered? > >> > > > > > >> > > > > I know I can do something like cat ->file but that makes it > hard to > >> > > > > sync stdout and stderr (both are unbuffered in Java) with the > file > >> > > > > version of stdin > >> > > > > > >> > > > > >> > > > "stdbuf" might be what you look for: > >> > > > > >> > > > https://man.freebsd.org/cgi/man.cgi?query=3Dstdbuf > >> > > > >> > > Will likely need to play with it more but stdbuf -i 0 -o 0 cat -|c= at > >> > > didn't produce the expected immediate echo I still had to hit retu= rn > >> > > > >> > > >> > Your console is linebuffered, so "cat" receives lines. IIRC "cat" > disables linebuffer on input by itself, so you should use someting else f= or > testing. > >> > > >> > Nik > >> > > >> > >> I am pretty convinced by the following test it is not working as > advertised: > >> > >> aryehl@neomarx:~/Desktop % cat foo.c > >> #include > >> #include > >> #include > >> > >> int main() > >> { > >> int in=3Dfcntl(STDIN_FILENO, F_DUPFD, 0); > >> int out=3Dfcntl(STDOUT_FILENO, F_DUPFD, 0); > >> char c=3D0; > >> > >> do { > >> read(in,&c,1); > >> write(out,&c,1); > >> } while(c!=3DEOF); > >> } > >> aryehl@neomarx:~/Desktop % !cc > >> cc foo.c > >> aryehl@neomarx:~/Desktop % stdbuf -i 0 -o 0 ./a.out > >> this is not echoing! > >> this is not echoing! > >> neither is this > >> neither is this > >> ^C > >> aryehl@neomarx:~/Desktop % > >> > >> -- > >> Aryeh M. Friedman, Lead Developer, http://www.PetiteCloud.org > >> > > > > stdbuf only works for stdio buffering of which read(2) and write(2) > aren't. > > I also tried it with System.in.read() in Java and it was also buffered > but according to the openjdk source it appears that this is on > purpose. > > > > -- > Aryeh M. Friedman, Lead Developer, http://www.PetiteCloud.org > When you just `./a.out` you're being bitten by the tty. You can manipulate that terminal to do what you want. Start reading termios(4). Without a tty you will only get a character at a time with the following: #include int main(int argc, char **argv) { char ch; for(;;){ ssize_t r =3D read(0,&ch,1); if(!r) break; write(1, &ch, 1); } _exit(0); } __________________ :(){ :|:& };: --00000000000033603105fda9e4c9 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


On Thu, Jun 8, 2023 at 10:5= 5=E2=80=AFPM Aryeh Friedman <aryeh.friedman@gmail.com> wrote:
On Thu, Jun 8, 2023 at 10:32=E2=80=AFPM Paul Proca= cci <pprocacci@= gmail.com> wrote:
>
>
>
> On Thu, Jun 8, 2023 at 9:22=E2=80=AFPM Aryeh Friedman <aryeh.friedman@gmail.com<= /a>> wrote:
>>
>> On Thu, Jun 8, 2023 at 6:37=E2=80=AFPM Dr. Nikolaus Klepp <dr.klepp@gmx.at> wr= ote:
>> >
>> > Anno domini 2023 Thu, 8 Jun 17:22:38 -0400
>> >=C2=A0 Aryeh Friedman scripsit:
>> > > On Thu, Jun 8, 2023 at 2:39=E2=80=AFPM Dr. Nikolaus Klep= p <dr.klepp@gmx.at<= /a>> wrote:
>> > > >
>> > > > Anno domini 2023 Thu, 8 Jun 14:01:19 -0400
>> > > >=C2=A0 Aryeh Friedman scripsit:
>> > > > > Under Java stdin (System.in) is a buffered str= eam not sent to the
>> > > > > application until return is pressed.=C2=A0 But= , Java can read from
>> > > > > files/sockets and other generic InputStreams u= nbuffered.=C2=A0 =C2=A0So I was
>> > > > > wondering if there is a command that will make= stdin go to a file so
>> > > > > that Java can open that file and read it unbuf= fered?
>> > > > >
>> > > > > I know I can do something like cat ->file b= ut that makes it hard to
>> > > > > sync stdout and stderr (both are unbuffered in= Java) with the file
>> > > > > version of stdin
>> > > > >
>> > > >
>> > > > "stdbuf" might be what you look for:
>> > > >
>> > > > https://man.freebsd.org/cg= i/man.cgi?query=3Dstdbuf
>> > >
>> > > Will likely need to play with it more but stdbuf -i 0 -o= 0 cat -|cat
>> > > didn't produce the expected immediate echo I still h= ad to hit return
>> > >
>> >
>> > Your console is linebuffered, so "cat" receives lin= es. IIRC "cat" disables linebuffer on input by itself, so you sho= uld use someting else for testing.
>> >
>> > Nik
>> >
>>
>> I am pretty convinced by the following test it is not working as a= dvertised:
>>
>> aryehl@neomarx:~/Desktop % cat foo.c
>> #include <stdio.h>
>> #include <fcntl.h>
>> #include <unistd.h>
>>
>> int main()
>> {
>>=C2=A0 =C2=A0 =C2=A0int in=3Dfcntl(STDIN_FILENO, F_DUPFD, 0);
>>=C2=A0 =C2=A0 =C2=A0int out=3Dfcntl(STDOUT_FILENO, F_DUPFD, 0);
>>=C2=A0 =C2=A0 =C2=A0char c=3D0;
>>
>>=C2=A0 =C2=A0 =C2=A0do {
>>=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0read(in,&c,1);
>>=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0write(out,&c,1);
>>=C2=A0 =C2=A0 =C2=A0} while(c!=3DEOF);
>> }
>> aryehl@neomarx:~/Desktop % !cc
>> cc foo.c
>> aryehl@neomarx:~/Desktop % stdbuf -i 0 -o 0 ./a.out
>> this is not echoing!
>> this is not echoing!
>> neither is this
>> neither is this
>> ^C
>> aryehl@neomarx:~/Desktop %
>>
>> --
>> Aryeh M. Friedman, Lead Developer, http://www.PetiteCloud.org=
>>
>
> stdbuf only works for stdio buffering of which read(2) and write(2) ar= en't.

I also tried it with System.in.read() in Java and it was also buffered
but according to the openjdk source it appears that this is on
purpose.



--
Aryeh M. Friedman, Lead Developer, http://www.PetiteCloud.org


When you just `./a.out` you&= #39;re being bitten by the tty.
You can manipulate that termi= nal to do what you want.=C2=A0 Start reading termios(4).

Without a tty you will only get a character at a time with the follo= wing:

#include <unistd.h>

int main(int argc,= char **argv)
{
=C2=A0 char ch;
=C2=A0 for(;;){
=C2=A0 =C2=A0 s= size_t r =3D read(0,&ch,1);
=C2=A0 =C2=A0 if(!r) break;
=C2=A0 = =C2=A0 write(1, &ch, 1);
=C2=A0 }
=C2=A0 _exit(0);
}

_________= _________

:(){ :|:& };:
--00000000000033603105fda9e4c9--