Linux Programming

• sid: A session is a collection of process groups (jobs). All of the processes in a session have the same session identifier.

A session leader is the process that created the session, and its process ID becomes the session ID.

• gid: Each process in a process group has the same integer process group identifier, which is the same as the process

ID of one of the processes in the group, termed the process group leader.

A session can have any number of background process groups(background jobs), which are created by terminating a command with the ampersand & character.