I try to collect importent events from syslog and in my
syslog conf, there is something like this:
I have a program, which opens this pipe and reads the messages from it.
But how this pipe works ? Where can I probably read something about the details, like: Is the pipe buffered, what happens to the sender, if the pipereader dies, is it possibly to connect again, how is the buffersize configured, etc.
Any help would be really great!
Thanks so far and
best regards,
++mabra
Last edited by joeyg; 01-02-2013 at 09:45 PM..
Reason: Please wrap commands and data in CodeTags
Hi All,
I am facing a vague issue while trying to make two process talk to each
other using named pipe.
read process
=========
The process which reads, basically creates FIFO using
mkfifo - ret_val = mkfifo(HALF_DUPLEX, 0666);) func.
It then opens the pipe using open func - fd =... (1 Reply)
Hi All,
I am facing a vague issue while trying to make two process talk to each
other using named pipe.
read process
=========
The process which reads, basically creates FIFO using
mkfifo - ret_val = mkfifo(HALF_DUPLEX, 0666) func.
It then opens the pipe using open func - fd = open... (2 Replies)
Hey folks,
i need communicate between 2 processes in a reliable manner. The information delivery has to be guarenteed. I thought about proc 2 sending a signal to proc 1 when information has being written to disc and wirte() has been verified (sync/flush). The IPC method for the data is named... (4 Replies)
Gurus,
I've a File Transaction Server, which communicates with other servers and performs some processing.It uses many Named PIPE's.
By mistake i copied a named PIPE into a text file.
I heard that PIPE files shouldn't be copied.Isn't it?
Since it's a production box, i'm afraid on... (2 Replies)
I did
cat < myFile >> myPipe
I was hoping that if I did ls -l, myPipe would now be holding the contents of myFile, and would be the same size. But it was 0.
Also strange was that when I did the command above, cat did not return control back to the shell. Why?
thanks (4 Replies)
I would like to pipe (redirect ? - what is the right term?) the output of my script to a file named with the current date.
If I run this at a command prompt:
date +'%Y%m%d"
...it returns "20110429"
OK, that's good... so I try:
./script.sh > "'date +%Y%m%d'.csv"
I get a file... (1 Reply)
Hi,
I want to use a Named pipe to get input from a growing file for further processing. When I prototype this scenario using a while loop, the data is not written to the named pipe.
This the script I use to get data into the Named pipe:
#!/bin/ksh
mkfifo pipe
while (( n <= 10 ))
do
echo... (2 Replies)
Hi,
I am getting data into a Named pipe. Does Named pipe have any size restriction; I know it does not have any storage and it just passes on the data to the next process.
I want to know, if there will be a difference in the Named pipe performance if the data input is more. (I am using DB2... (1 Reply)
Ok, I can't seem to figure this out or find anything on the web about this.
I'm on Sun Solaris, UNIX.
I have the following test script:
#!/bin/ksh
touch test.file
LOG=./tmp.log
rm -f ${LOG}
PIPE=./tmp.pipe
mkfifo ${PIPE}
trap "rm -f ${PIPE}" EXIT
tee -a ${LOG} < ${PIPE} &
... (17 Replies)
Discussion started by: Ditto
17 Replies
LEARN ABOUT OSX
pipe
PIPE(2) BSD System Calls Manual PIPE(2)NAME
pipe -- create descriptor pair for interprocess communication
SYNOPSIS
#include <unistd.h>
int
pipe(int fildes[2]);
DESCRIPTION
The pipe() function creates a pipe (an object that allows unidirectional data flow) and allocates a pair of file descriptors. The first
descriptor connects to the read end of the pipe; the second connects to the write end.
Data written to fildes[1] appears on (i.e., can be read from) fildes[0]. This allows the output of one program to be sent to another pro-
gram: the source's standard output is set up to be the write end of the pipe; the sink's standard input is set up to be the read end of the
pipe. The pipe itself persists until all of its associated descriptors are closed.
A pipe whose read or write end has been closed is considered widowed. Writing on such a pipe causes the writing process to receive a SIGPIPE
signal. Widowing a pipe is the only way to deliver end-of-file to a reader: after the reader consumes any buffered data, reading a widowed
pipe returns a zero count.
The generation of the SIGPIPE signal can be suppressed using the F_SETNOSIGPIPE fcntl command.
RETURN VALUES
On successful creation of the pipe, zero is returned. Otherwise, a value of -1 is returned and the variable errno set to indicate the error.
ERRORS
The pipe() call will fail if:
[EFAULT] The fildes buffer is in an invalid area of the process's address space.
[EMFILE] Too many descriptors are active.
[ENFILE] The system file table is full.
SEE ALSO sh(1), fork(2), read(2), socketpair(2), fcntl(2), write(2)HISTORY
A pipe() function call appeared in Version 6 AT&T UNIX.
4th Berkeley Distribution February 17, 2011 4th Berkeley Distribution