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Re: named fifo (byte - byte transfer)
From: |
CEL |
Subject: |
Re: named fifo (byte - byte transfer) |
Date: |
Wed, 30 Oct 2019 14:02:09 +0000 |
Hi,
we've covered pretty much exactly your three questions in a mailing
list thread earlier this month. Let me link to the archive:
https://lists.gnu.org/archive/html/discuss-gnuradio/2019-10/index.html
It's the mails with subject "fifo / file source".
In essence, "cat" is buffered, and so you need to use a different
program that makes sure the fstream it outputs is unbuffered. GNU Radio
has no influence on the buffering your writing process does.
Best regards,
Marcus
On Wed, 2019-10-30 at 14:19 +0200, hamzeh elsayed wrote:
> Hi,
>
> I did the following:
> 1) in linux terminal I create a fifo file as :
> $ mkfifo in
> 2) in gnuradio I did:
> file source (file name : in)-> throttle -> file sink (output file: out.txt)
>
>
>
> then for running, I did the following:
> 1) run the flowgraph
> 2) in terminal, I run
> $ cat > in
>
> then only if I wrote a large number for characters, those characters are
> transferred.
>
> for example if I wrote 10 bytes in fifo in to transmit them, any byte is not
> written in the file out.txt. while, if 15000 bytes are written in fifo in the
> some of these 15000 bytes are transferred to out.txt but not all of them.
>
> it seems to me that fifo in gnuradio does not transfer each byte alone, is
> saves a number of bytes as a packet then it send them together.
>
> my question is :
>
> 1) how to transfer each byte alone in my flowgraph example using unix pipe?
>
> 2) if I can not transfer each byte alone, what is the size of packet that are
> buffered and the transferred together?
>
> 3) If the last bytes are less than packet size, then they are not
> transferred. therefore, how I can I transfer them?
>
> if I have to do padding then I have to know the size of the buffer or packet?
> Is it fixed or not?
>
> Thanks for your time and help
>
> Best regards
smime.p7s
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