LinuxQuestions.org - Linux Application Programming

Linux Application Programming Notes about programming for user space applications.

Logrotate - Not Just for the System

Posted 05-13-2014 at 01:26 PM by rtmistler

I've seen a few threads about logrotate. Two thread types I've noticed are:

Persons not understanding logrotate and how to use it
Persons not happy with logrotate and it's normal means of operation - mainly because they'd like to use it for something other than the system log files.

My intentions here are to cover the second case however I will start describing a bit about logrotate and how to use it. So those who are new to logrotate and seeking some guidance, the general overview section...

rtmistler

Moderator

Posted in Linux Application Programming

Views 2697 Comments 1 rtmistler is offline

How to kill those Zombies

Posted 06-13-2013 at 03:22 PM by rtmistler

Tags process, signal, zombie

When a process has ended, signals are emitted to it's parent to indicate that the process is done. This does not delete the process however, information about the process remains with the system until such time as the parent checks that signal. The process becomes a zombie until the exit signal is checked.

The reason for this is closure.

Rather than have that process go away and never give an understanding as to why it went away, it stays as a zombie so that the parent...

rtmistler

Moderator

Posted in Linux Application Programming

Views 2604 Comments 0 rtmistler is offline

USB Receive and Rapid Parse, GPS Example

Posted 06-11-2013 at 08:17 AM by rtmistler

Tags gps, parse, usb serial

Introduction
This is more of a general programming example which can be applied to other systems, in addition to Linux.

This is a discussion of an application programming scenario where a GPS device is attached via a serial USB connection to the system. Challenges faced in this project include:

Detecting a USB Serial Resource on your System

Configuring and Controlling a USB Serial Resource

Processing Receive Data from the USB Serial Resource

De-Framing GPS Data

Parsing GPS Data

...

rtmistler

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Posted in Linux Application Programming

Views 3640 Comments 0 rtmistler is offline

Using PIPES for Interprocess Communications

Posted 06-01-2013 at 05:46 PM by rtmistler

When you look at Linux documentation, there are a variety of ways to communicate across processes. I've tried a few, http://tldp.org/LDP/tlk/ipc/ipc.html, including signals, semaphores, IPC, shared memory, and PIPES.

My Summary of Each IPC Type

Signals
Signals are singular indicators which carry very one-dimensional information. They are fast, and they are supported by system calls where you can send one easily or wait, blocking or non-blocking to see if you've...

rtmistler

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Posted in Linux Application Programming

Views 1282 Comments 0 rtmistler is offline

Creating a daemon to launch and monitor your processes

Posted 05-30-2013 at 01:11 PM by rtmistler
Updated 12-09-2014 at 02:29 PM by rtmistler

Tags daemon(), fork()

Most of my Linux application architectures are really a collection of processes which are started at boot and need be maintained in case something unexpected occurs. Long ago I started with daemons, but also learned and developed a few additional concepts.

The links have changed over the years, but if you search for "linux daemon" and go down some of the search results, you'll find similar entries as:

http://www.netzmafia.de/skripten/uni...mon-howto.html...

rtmistler

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Posted in Linux Application Programming

Views 5018 Comments 0 rtmistler is offline

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