Inter Process Communication usually refers to kernel services that allow processes on the same machine to communicate with each other.

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Which process group my program belongs to started from bash?

If I run a program from bash then does my program belong to the same process group of the bash or it belongs to a new process group? As I am making a shell in C, so I need to handle SIGINT signal. ...
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i am getting conflict error when trying to run the following code of read write locks using pthreads [migrated]

Here is the code for my program incr_rwlock1.c /* include main */ #include "unpipc.h" #include "pthread_rwlock.h" /* our implementation header */ #define MAXNTHREADS 100 int ...
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41 views

Why does grep goes into blocking stage? [closed]

I am making a test My task will be one child pipelining the output to the input of another another child. I am using ps -ef as the first command(by using execlp()) and grep root as the second ...
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49 views

Deadlock on read/wait [closed]

My process deadlocks. master looks like this: p=Popen(cmd, stdin=PIPE, stdout=PIPE) for ....: # a few million p.stdin.write(...) p.stdin.close() out = p.stdout.read() p.stdout.close() exitcode = ...
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24 views

Why signal function is not able to call my signal Handler? [closed]

Here I have written a signal handler function named as handler Correspondingly this handler is registered to kernel using the signal function that will be invoked when SIGCHLD signal is generated by ...
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1answer
19 views

ipcs(1) POSIX equivalent to System V

I know that with ipcs(1) command, one can monitor System V message queues, shared memory and semaphores, but how do I monitor POSIX message queues, shared memory and semaphores. For POSIX message ...
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1answer
41 views

Linux - check processes using IPC channels

This is related to my previous question. Given that I can find the statistics of IPC channels in my Linux system (e.g. sys V IPC), how can I find which processes are using certain IPC channel ...
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49 views

Linux - check IPC stats

What is the best way of checking current status of different types of IPC in Linux (including uids) ? I want to inspect named pipes, half duplex pipes, unix domain sockets, signals. I know for sys V ...
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How to list all object paths under a dbus service?

This is a follow-up question to A list of available DBus services. The following python code will list all available DBus services. import dbus for service in dbus.SystemBus().list_names(): ...
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105 views

UNIX sockets vs AF_NETLINK vs Kdbus vs Binder

What are essential differences between those IPCs? Which are main use cases? Is there some consolidated comparison table between them somewhere? Something like: Protocol: AF_UNIX | ...
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37 views

Reasons for IPC control in Linux [closed]

Linux OS has several IPC mechanisms like named pipes, sys V, d-bus etc. Each of these mechanisms always has senders and receivers of IPC; each mechanism uses some way to control IPC between senders ...
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102 views

Porting Binder IPC to Linux

Android provides a device driver based IPC mechanism called Binder. I see it as one of the staging drivers in Linux. Although I can have a linux kernel running with this device driver, if I want to ...
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process waiting for a semaphore

If I have a process that is in sleep state and i can see in ps' column WCHAN that is waiting to obtain a semaphore, is there any way to find the adress of that semaphore?
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98 views

Getting started with D-Bus using C++ and systemd

I'm trying to get up & running with systemd dbus on my Linux desktop machine. What is a good place to start ? Is there an exhaustive documentation of systemd dbus API ? My first goal is to enable ...
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60 views

process blocked in msgrcv

I have a process that is blocked in msgrcv as shown by ps -eo pid,tid,wchan. Is there any way to find the PID of the process that my process is expecting to receive a message from? The communication ...
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45 views

Ubuntu Linux - one app invoke the other

I recently installed Viber on my Ubuntu machine. I notice that in the Viber application, when using chat, the sender can send a location as well. When I click the location icon in the chat window, the ...
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1answer
226 views

Why does the clock need a shared memory segment?

This is a combination of programming and Linux question but I think it suits better here. I am writing an application that works with ipcs (shared memory segments) and after each running I am ...
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1answer
288 views

Advantages of using named pipes and sockets rather than temporary files

I have two cooperating programs. One program just writes its output to a file and the other one then reads from the file and spits the data out for the front end to work with. I have been reading ...
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133 views

Stopping syslogd also closes /dev/log UNIX domain socket

I am working on a project and from some testing I found out that stopping syslogd daemon also closes /dev/log socket. Is there some other way so that even if syslogd is down, /dev/log socket still ...
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1answer
32 views

What are the files in /tmp that start with “qipc”?

There are empty files like this in my /tmp directory: qipc_sharedmemory_soliddiskinfomemac5ffa537fd8798875c98e190df289da7e047c05 ...
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730 views

Can a process running in a linux container communicate with another process running on the host OS via IPC?

I have 2 processes A and B. Currently, both A and B are running on the same OS (RHEL6.2) and the processes can intercommunicate via TCP sockets. My objective is to run process B in a Linux Container ...
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`/proc/$PID/cwd` : is there a POSIX equivalent?

Linux has a /proc directory and file‑system, which as far as I can tell, is not part of POSIX. In each /proc/$PID subdirectories, is a symbolic link, cwd, pointing to the actual working directory of ...
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206 views

Whats the sense of dbus objects?

Despite reading through tons of Dbus - tutorials, I still struggle to understand the whole concept. In my opinion this was one of the best explanations so far: ...
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Find and close/unlink message queues in the system

I have a SLES-11 machine on which I am not the root where I am building software code that makes extensive use of message queues. Due to some bugs, Now have an error: mq_open: Too many open files I ...
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1answer
979 views

Which IPC is supported in Ubuntu 12.04: POSIX or System V

How do I know which type of IPC is supported in Ubuntu 12.04: System V or POSIX Is there any command to get this ?
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604 views

Creating a terminal device for interprocess communication

I'd like to know how to create a terminal device to simulate a piece of hardware connected through a serial port. Basically, tty device with a certain baud rate that can be read from and written to ...
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Are FIFO, pipe & Unix domain socket the same thing in Linux kernel?

I heard that FIFOs are named pipes. And they have exactly the same semantics. On the other hand, I think Unix domain socket is quite similar to pipe (although I've never made use of it). So I wonder ...
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So the design of client-server separation is not the bottleneck of X Window?

In the answer of this, it mentioned: People also hear that X uses the "network" and think this is going to be a performance bottleneck. "Network" here means local UNIX domain socket, which has ...
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linux command to check POSIX message queue

We can check the details of system V message queue with the help of ipcscommand. Is there any command to check POSIX message queue in Linux?
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3answers
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Does one end of a pipe have both read and write fd?

As far as I understood one end of a pipe has both read and write fd's and the other end also has read and write fd's. Thats why when we are writing using fd[1], we are closing the read end e.g. ...
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3answers
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What after exec() in ls command. Is the parent process printing the output to the console or the child?

I have a simple doubt on execution of the command ls. As per my understanding from the research I have done on the internet, I understood the below points. When we type ls command shell interprets ...
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2answers
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Sending SIGUSR1 to parent

When I do a kill -SIGUSR1 $PPID I get kill: (1) - Operation not permitted . How can I overcome this?
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Why message queues are not being used for any system level applications in Ubuntu OS?

In my Linux machine, when i run 'ipcs' command, I have the below information listed srinivas@srinivas-G41MT-S2:~$ ipcs -a ------ Shared Memory Segments -------- key shmid owner ...
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Why there are only two user defined signals?

In the list of signals defined in a linux system, there are two signals stated as User Defined signals (SIGUSR1 and SIGUSR2). Other signals will be raised or caught in specific situations, but SIGUSRs ...
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A list of available DBus services

Is there such a thing as list of available DBus services? I've stumbled upon a few (like those provided by NetworkManager, Rhythmbox, Skype, HAL). I wonder if I can find a rather complete list of ...
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1answer
709 views

Preventing ChromeOS from blanking the screen when working on a different tty

I am running Archlinux in a chroot alongside Chrome OS on a chromebook. The original project is there, my fork of it is here (mostly similar). The issue is that the display power management of Chrome ...
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1answer
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How can I determine the connection method used by a MySQL client?

When using a MySQL client (e.g. mysql) how can I determine whether it connected to the server using a Unix socket file or by using TCP/IP?
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735 views

IPC: Shared memory killed process notification

In shared memory system, when two processes share a shared memory segment, after one process is killed, how will the other running process be notified of the killed process by the shared memory system ...
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1answer
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How do I increase the number of semaphore arrays in Linux?

In a Debian lenny server running postgresql, I noticed that a lack of semaphore arrays is preventing Apache from starting up. Looking at the limits, I see 128 arrays used out of 128 arrays maximum, ...
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Is there a way to intercept interprocess communication in Unix/Linux?

For intercepting/analyzing network traffic, we have a utility called Wireshark. Do we have a similar utility for intercepting all the interprocess communication between any two processes in ...