process of creating system call

surabhi suppu · 03-24-2011, 11:23 AM

Hi ..,
how to create a new system call Linux? what is the process of creating ?my project is to create a system call for displaying owner of a file..where exactly we have to write the system call code? and where are the places need to change ?
Thank u

rtmistler · 03-24-2011, 11:43 AM

You just need to create a binary program that performs the actions you wish and then place that in a directory that is included in your path; typically /usr/sbin is a good choice.

If you're talking about adding to your shell, then you'll need to grab the source for that shell and rebuild it. Typically that's not a necessity and you just need a script or executable that accomplishes the task you wish. For that matter, you can use a script to get the output of ls and use sed to edit that output to be in a suitable form.

unSpawn · 03-24-2011, 01:27 PM

Quote:

Originally Posted by surabhi suppu

my project is to create a system call

If this is your project then you should start by doing research. O'Reilly's Understanding the Linux Kernel version 3 (ULK3) would be a suggested starting point to read about how binaries interact with libraries and how userland interacts with the kernel. Then using your favorite search engine to search for "create system call" (and searching LQ for the same) should yield a ton of examples.

bsat · 03-25-2011, 12:26 AM

This might help
http://www.amazon.com/Linux-Kernel-D.../dp/0672325128

There is enough material available on line if you search

Aquarius_Girl · 03-25-2011, 02:24 AM

and hit out Google with the keywords:
Tldp implementing a system call Linux 2.6

Tinkster · 04-14-2011, 02:07 PM

Moved: This thread is more suitable in <PROGRAMMING> and has been moved accordingly to help your thread/question get the exposure it deserves.