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Unix Process Conclusion

You have completed this module on processes. You should now be able to:
  1. Define what a process is
  2. Identify the various types of processes you may encounter on a UNIX system
  3. Know the basic process attributes and their role in access control
  4. Understand how new processes come into being
  5. Determine related families of processes
  6. Create, schedule, and run a periodic process

Key terms

The following terms were used in this module:
  1. cron: The cron daemon lets you automate the running of processes and applications and lets you schedule a particular time for a process to run.
  2. daemon: A daemon is a process that is not associated with any terminal and which is dedicated to handling a particular task.
  3. forking: Forking is the mechanism by which the system starts a new process, waits for it to finish, then generates a new output prompt and waits for the next command.
  4. init: The init process is the first process to run on a system. All other processes on the system are derived from init by the fork and exec procedures, either directly or indirectly.
  5. interpreter: An interpreter is a program that reads and executes line by line other programs written in the appropriate programming language.
  6. periodic process: A periodic process is any process that runs at a specified time.
  7. process: A UNIX process is a running program.
  8. process ID (PID): A process ID (PID) is a unique number associated with each process on the system. PIDs start with number 1, which is the init process.
  9. SGID permission: The SGID permission sets a process's group ID on execution.
  10. shell: The shell is a program that interprets your commands and passes them to the operating system for further processing. You enter commands at the shell prompt (also called the system prompt or command prompt).
  11. Shell script
  12. SUID permission

Commands

The following commands were discussed in this module:
Command Purpose
at Runs a program at one specified time.
batch Executes commands entered from standard input. Similar to at but uses less system resources because it runs one process, waits for it to end, then runs another.
crontabs Allows you to create and manage the entries that inform the cron daemon about the applications and processes you want to automate.
id Shows user ID and group membership of a file.
kill Terminates a process.
ps Examines running processes on the system.
sleep Allows you to specify a certain period of time (usually in seconds) to wait before the system executes a command.
source Allows you to execute programs that have not yet been compiled.
which Displays which command gets run under a given name.

Unix Processes - Quiz

Click the Quiz link below to take a multiple-choice quiz covering what you learned in this module.
Unix Processes - Quiz