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O_DIRECT "packet mode" pipes on Linux
From: |
Vito Caputo |
Subject: |
O_DIRECT "packet mode" pipes on Linux |
Date: |
Tue, 22 Sep 2020 20:23:06 -0700 |
Hello list,
Is there any chance we could get a | modifier for enabling O_DIRECT on the
created pipe? "Packet" style pipes have some interesting and potentially
useful properties, it would be nice if bash made them more accessible.
pipe(2) O_DIRECT excerpt:
O_DIRECT (since Linux 3.4)
Create a pipe that performs I/O in "packet" mode. Each write(2)
to the pipe is dealt with as a separate packet, and read(2)s
from the pipe will read one packet at a time. Note the follow‐
ing points:
* Writes of greater than PIPE_BUF bytes (see pipe(7)) will be
split into multiple packets. The constant PIPE_BUF is
defined in <limits.h>.
* If a read(2) specifies a buffer size that is smaller than the
next packet, then the requested number of bytes are read, and
the excess bytes in the packet are discarded. Specifying a
buffer size of PIPE_BUF will be sufficient to read the
largest possible packets (see the previous point).
* Zero-length packets are not supported. (A read(2) that spec‐
ifies a buffer size of zero is a no-op, and returns 0.)
Older kernels that do not support this flag will indicate this
via an EINVAL error.
Regards,
Vito Caputo
- O_DIRECT "packet mode" pipes on Linux,
Vito Caputo <=
- Re: O_DIRECT "packet mode" pipes on Linux, Chet Ramey, 2020/09/23
- Re: O_DIRECT "packet mode" pipes on Linux, Vito Caputo, 2020/09/23
- Re: O_DIRECT "packet mode" pipes on Linux, Lawrence Velázquez, 2020/09/23
- Re: O_DIRECT "packet mode" pipes on Linux, Vito Caputo, 2020/09/24
- Re: O_DIRECT "packet mode" pipes on Linux, Robert Elz, 2020/09/24
- Re: O_DIRECT "packet mode" pipes on Linux, Vito Caputo, 2020/09/24
- Re: O_DIRECT "packet mode" pipes on Linux, Robert Elz, 2020/09/24
- Re: O_DIRECT "packet mode" pipes on Linux, Dale R. Worley, 2020/09/25