I'm creating a program which reads millions of bytes from the PIPE and do some processing. As the data is more, the idea is to read the pipe parallely.
Sun Solaris 8
See the code below:
parallel_wot.sh
Now the problem is, as the pipe is read in parallel, once the pipe is emptied all other processes are waiting to read from the pipe except 1. The questions I now have is , how to exit from reading the pipe if there are no records.
Last edited by Scrutinizer; 04-06-2018 at 08:11 AM..
Reason: Extra code tags
Hi
I have apeculiar problem with sockets.
I have a shared object for my client program.
when I send a request to the server, it is suppose to process and sends back the result string to the client.
For the first request, it is working fine i.e. client sends the req. and gets the... (1 Reply)
Hi,
I am trying to test the exit status of the cleartool lsvtree statement below, but it doesn't seem to be working due to the tail pipe, which it is testing instead. Is there a way around this without adding a tonne of new code?
cleartool lsvtree $testlocation/$exe_name | tail -15
... (10 Replies)
I have a question about how to get the exit code of the first command when it appears in a pipe-lined command.
For example, I have the following script:
grep abc dddd | tee -a log
if ]
then
echo "ERROR!"
fi
In the above script, ] is supposed to test the exit code of "grep abc... (3 Replies)
Hi all,
Does anybody know or guide me on how to remove the first N bytes and the last N bytes from a binary file? Is there any AWK or SED or any command that I can use to achieve this?
Your help is greatly appreciated!!
Best Regards,
Naveen. (1 Reply)
Hi,
If I want to copy a 1024 byte data stream in to the target location in 3-bytes chunk, I guess I can use the following script.
dd bs=1024 count=3 if=/src of=/dest
But, I would like to know, how to do it via a C program. I have tried this with memcpy(), that did not help. (3 Replies)
Guys, I have a problem :confused: and I need some help:
I've to process many huge zip files.
I'd code an application that receive the data from a pipe, so I can simple unzip the data and send it (via pipe) to my app.
Something like that:
gzip -dc <file> | app
The problem is: How can I... (7 Replies)
Hello guys. I really hope someone will help me with this one..
So, I have to write this script who:
- creates a file home/student/vmdisk of 10 mb
- formats that file to ext3
- mounts that partition to /mnt/partition
- creates a file /mnt/partition/data. In this file, there will... (1 Reply)
hello,
suppose, entered input is of 1-40 bytes, i need it to be converted to 40 bytes exactly.
example: if i have entered my name anywhere between 1-40 i want it to be stored with 40 bytes exactly.
enter your name:
donald duck (this is of 11 bytes)
expected is as below - display 11... (3 Replies)
Hi expert,
How do i exit to while read, below is the script.
I need to exit after execute echo or command.
or any scripts that can search two patterns and if they found any patterns execute the command and exit.
Thanks a lot..
tail -fn0 /tmp/test.log | \
while read line ; do
... (12 Replies)
I have created a fifo named pipe in solaris, which writes the content of a file, line by line, into pipe as below:
$ mkfifo namepipe
$ cat books.txt
"how to write unix code"
"how to write oracle code"
$ cat books.txt >> namepipe &
I have a readpipe.sh script which reads the named... (2 Replies)
Discussion started by: naveen mani
2 Replies
LEARN ABOUT PLAN9
pipe
PIPE(2) System Calls Manual PIPE(2)NAME
pipe - create an interprocess channel
SYNOPSIS
#include <u.h>
#include <libc.h>
int pipe(int fd[2])
DESCRIPTION
Pipe creates a buffered channel for interprocess I/O communication. Two file descriptors are returned in fd. Data written to fd[1] is
available for reading from fd[0] and data written to fd[0] is available for reading from fd[1].
After the pipe has been established, cooperating processes created by subsequent fork(2) calls may pass data through the pipe with read and
write calls. The bytes placed on a pipe by one write are contiguous even if many processes are writing. 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.
The number of bytes available to a read(2) is reported in the Length field returned by fstat or dirfstat on a pipe (see stat(2)).
When all the data has been read from a pipe and the writer has closed the pipe or exited,read(2) will return 0 bytes. Writes to a pipe with no reader will generate a note sys: write on closed pipe.
SOURCE
/sys/src/libc/9syscall
SEE ALSO intro(2), read(2), pipe(3)DIAGNOSTICS
Sets errstr.
BUGS
If a read or a write of a pipe is interrupted, some unknown number of bytes may have been transferred.
When a read from a pipe returns 0 bytes, it usually means end of file but is indistinguishable from reading the result of an explicit write
of zero bytes.
PIPE(2)