Process Control Functions The fork() FunctionĪs already discussed in the article creating a daemon process in C, the fork function is used to create a process from within a process. It is a kernel level process responsible for all the process scheduling that takes place inside the system. Process ID 0 is of the scheduler of the system.

The startup files read by the init process to achieve a certain state are The init process is a user level process but runs with root privileges and is responsible for bringing the system up to a state once the kernel has bootstrapped. The program file for the init process can be found either in /etc/init or in /sbin/init. This is the first process that is started once a system boots up. So a delay is added before reusing the same process ID. This is because the process ID that was associated with the previous process that is now terminated may well be into use in form of a file name etc. When a process is terminated from system, its process ID is made available for reuse.īut there is a specific delay that is accounted before making the process ID available for reuse. This uniqueness of the process ID sometimes is used by the process to create some unique filenames. These numbers are unique across the processes running in the system. Process IDs are the process identifiers that are non negative numbers associated with a process. Linux Processes Series: part 1, part 2, part 3 (this article). In this article, we will start from a small explanation of process IDs and then we will quickly jump on to the practical aspects where-in we will discuss some process related C functions like fork(), execv() and wait() .

Process scheduling program in c