In Linux, a process is an instance of a program that is being executed. Each process has its own memory space and is independent of other processes. This means that a process can run, be suspended, terminated, or be restarted without affecting any other processes.
In Linux, processes are represented by the
struct task_struct data structure, which is defined in the
sched.h header file. This data structure contains information about the process, such as its PID, memory usage, state, and other attributes.
Each process in Linux has a unique process ID (PID) that is assigned by the kernel. This PID is used to identify the process and to distinguish it from other processes within the operating system. The PID of a process can be obtained using the
getpid() function, which is defined in the
unistd.h header file.
Processes in Linux are created using the
fork() system call, which creates a new child process that is a copy of the calling process. The child process is then executed using the
exec() family of functions with separate memory space and a new PID, which replaces the child process’s memory space and execution context with the program specified in the function call
Processes in Linux can also communicate with each other using interprocess communication (IPC) mechanisms, such as pipes and message queues. This allows processes to share data and coordinate their execution.
In summary, a process in Linux is an instance of a program that is being executed. Each process has its own memory space and execution context, and it is identified by a unique process ID. Processes are created using the
fork() system call, and they can communicate with each other using IPC mechanisms.