I have some project which uses libdbus for IPC. The goal is to use systemd’s sd-bus instead of libdbus. There is documentation for sd-bus (here, here and etc), but that documentation doesn’t cover all aspects of D-Bus specification implementation. I spent a lot looking for at least any detailed explanation of sd-bus’ implementation, but didn’t find anything that could help
Tag: ipc
Running bash using posix instead of fork/execv
I have a CLI, one of the commands is entering into Linux bash shell. This is the code which does it using fork & execv: I want to replace the fork/execv and to use posix_spawn instead: But it doesn’t work. Any help? Answer Let’s look at what the code in the original fork/exec does: close all file descriptors open the
How would a Python script running on Linux call a routine in a Python script running under Wine?
I have a Python (3) script running on Linux, referred to as the main script, which has to call a routine from a proprietary DLL. So far, I have solved this with Wine using the following construct: The script dll_call.py is executed by a Windows Python (3) interpreter installed under Wine. It dumps the return values into a file which
POSIX message queue – Does it still exists after reboot?
On linux, wrote a simple program to create a POSIX message queue, and send a msg to it, after the process terminated, it seems the msg is still there. The questions are: Does the msg still there after reboot? If it exists, then it’s on disk, how did it guarantee the performance if it stores msg on disk instead of
Sending an arrow key with fprintf
I’m testing out pipes and have hit a little road block. I want to be able to simulate pressing the right arrow key through a file pointer opened by popen. The file pointer opens a display program on a different terminal, much like a projector. I would like to send a signal to advance the next image (the right arrow
What is a good Inter-Process Communication method between C and PHP in Linux
I actually don’t know whether I am asking a proper question. Let me describe my problem first. End user <-1-> web server (by PHP) <-2-> an internal process (by C or C++) <-3-> an external hardware The 1 should be something like ajax request. The 2 should be something like inter-process communication. The 3 should be uart RS232 communication. The
Proper implementation of an inter process communication (IPC)
Is the following a proper implementation of an inter-process communication? It seems to be working but I’m wondering if there could be a race condition leading to hanging. One constraint is that both processes need to be started independently and in any order. Answer Some stress tests showed no problem so the implementation seems OK if somebody wants to reuse
Fastest technique to pass messages between processes on Linux?
What is the fastest technology to send messages between C++ application processes, on Linux? I am vaguely aware that the following techniques are on the table: TCP UDP Sockets Pipes Named pipes Memory-mapped files are there any more ways and what is the fastest? Answer I would suggest looking at this also: How to use shared memory with Linux in
Waiting on multiple semaphores without busy-waiting (C/C++ Linux)
If I have more than one semaphore, how can I have a process block until at least one of the semaphores is free? I know I can do this with a busy-wait loop such as: But is there a way to do this without a busy-loop? Perhaps there’s some IPC technique other than semaphores that I should be using? Thanks
How to send integer with pipe between two processes!
I am trying to send an integer with pipe in a POSIX system but write() function is working for sending string or character data. Is there any way to send integer with a pipe? Regards Answer The safe way is to use snprintf and strtol. But if you know both processes were created using the same version of compiler (for