ASYNC(3) Library Functions Manual ASYNC(3)NAME
async - framing for a serial line to Datakit
SYNOPSIS
ctlfd = open(".../ctl", ORDWR);
write(ctlfd, "push async", 10);
DESCRIPTION
This is not a device, but rather a stream module (see stream(3)) that can be pushed onto a stream. This module provides the framing neces-
sary to treat a serial line as a Datakit trunk. It is usually pushed onto a stream before the dkmux module. The frame includes a CRC.
Any received frames with an incorrect CRC are discarded.
The format of a message upstream of the module is:
channel # low byte
channel # high byte
control byte (0 means none)
data bytes
The format of a frame is:
0x7d
0x7d
channel # low byte
channel # high byte
crc low byte
crc high byte
0x7d
0x7d
All control bytes in the frame are preceded by a 0x9d byte. All 0x9d and 0x7d bytes in the data are followed by a 0x00 byte to distinguish
them from framing or control specifiers.
SEE ALSO stream(3), cons(3), dk(3)SOURCE
/sys/src/9/port/stasync.c
ASYNC(3)
Check Out this Related Man Page
PIPE(3) Library Functions Manual PIPE(3)NAME
pipe - two-way interprocess communication
SYNOPSIS
bind #| dir
dir/data
dir/ctl
dir/data1
dir/ctl1
DESCRIPTION
An attach(5) of this device allocates two new streams joined at the device end. X/data and x/ctl are the data and control channels of one
stream and x/data1 and x/ctl1 are the data and control channels of the other stream.
Data written to one channel becomes available for reading at the other. Write boundaries are preserved: each read terminates when the read
buffer is full or after reading the last byte of a write, whichever comes first.
Written data is buffered in kernel stream blocks. The writer will block once the stream is full, typically after 32768 bytes or 16 writes.
The writer will resume once the stream is less than half full.
If there are multiple writers, each write is guaranteed to be available in a contiguous piece at the other end of the pipe. If there are
multiple readers, each read will return data from only one write.
The pipe(2) system call performs an attach of this device and returns file descriptors to the new pipe's data and data1 files. The files
are open with mode ORDWR.
SEE ALSO pipe(2)SOURCE
/sys/src/9/port/devpipe.c
PIPE(3)
Hello
Does a command already exist for formatting numbers in byte for example?
Just thought I would ask if there is a function for it or if I should write one myself, don't want to reinvent the wheel.
Example:
10 = 10 B
1234 = 1.234 kB
1500000 = 1.5 MB
Thanks by advance (1 Reply)
Hi All
Can anyone please suggest me how to remove the last byte from a falt file .This is from the last line's last BYTE.
Please suggest me something.
Thank's and regards
Vinay (1 Reply)
Hi guys,
i have a question about spliting a binary file into 2 chunks.
First chunk with all high bytes and the second one with all low bytes.
What unix tools can i use? And how can this be performed?
I looked in manpages of split and dd but this does not help.
Thanks (2 Replies)
Hi all,
i have a binary file splitted into 2 chunks, first part with all high bytes and the second part with all low bytes.
I need to combine the two chunks into one binary file like (eg. exactly the reverse of the splitting method solved in the thread # 130940)
Hi bytes file content:... (7 Replies)