- published: 18 Nov 2011
- views: 5634
Unix (trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, developed in the 1970s at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and others.
Initially intended for use inside the Bell System, AT&T licensed Unix to outside parties from the late 1970s, leading to a variety of both academic and commercial variants of Unix from vendors such as the University of California, Berkeley (BSD), Microsoft (Xenix), IBM (AIX) and Sun Microsystems (Solaris). AT&T finally sold its rights in Unix to Novell in the early 1990s, which then sold its Unix business to the Santa Cruz Operation (SCO) in 1995, but the UNIX trademark passed to the industry standards consortium The Open Group, which allows the use of the mark for certified operating systems compliant with the Single UNIX Specification (SUS). Among these is Apple's OS X, which is the Unix version with the largest installed base as of 2014.
From the power user's or programmer's perspective, Unix systems are characterized by a modular design that is sometimes called the "Unix philosophy", meaning that the operating system provides a set of simple tools that each perform a limited, well-defined function, with a unified filesystem as the main means of communication and a shell scripting and command language to combine the tools to perform complex workflows. Aside from the modular design, Unix also distinguishes itself from its predecessors as the first portable operating system: almost the entire operating system is written in the C programming language that allowed Unix to reach numerous platforms.
Process control is an engineering discipline that deals with architectures, mechanisms and algorithms for maintaining the output of a specific process within a desired range. For instance, the temperature of a chemical reactor may be controlled to maintain a consistent product output.
Process control is extensively used in industry and enables mass production of consistent products from continuously operated processes such as oil refining, paper manufacturing, chemicals, power plants and many others. Process control enables automation, by which a small staff of operating personnel can operate a complex process from a central control room.
Process control may either use feedback or it may be open loop. Control may also be continuous (automobile cruise control) or cause a sequence of discrete events, such as a timer on a lawn sprinkler (on/off) or controls on an elevator (logical sequence).
A thermostat on a heater is an example of control that is on or off. A temperature sensor turns the heat source on if the temperature falls below the set point and turns the heat source off when the set point is reached. There is no measurement of the difference between the set point and the measured temperature (e.g. no error measurement) and no adjustment to the rate at which heat is added other than all or none.
Running a process and putting it into the background and then moving it into the background. I used a copy command that would take a long time in the example. While a command is running you can suspend it with ctrl-z or kill it with ctrl-c. suspend a job ctrl -z terminate a job ctrl -c When a job is suspended it can be moved back to the foreground with `fg` and placed in the background (where it will continue to execute) with `bg`.
fg, bg, suspend & , suspend Ctrl+z, disown applications or processes jobs
This Tutorial explains Linux process control commands like ps, top, bf, fg, kill etc. All concepts are explained with elaborated examples. Tutorial Topics:- 1. How to background a process (bg). 2. How to foreground a background process (fg). 3. How to view all the background process (jobs). 4. How to foreground and background specific process from a list(ps). 5. How to search a process details. 6. How to search a process with process id. 7. How to view all the process of a user. 8. How to View view custom parameters of a process. 9. How to view system utilization in terms memory, cpu etc (top). 10.How to view all the process with their details like cpu usage, memory usage etc 11.How to kill a process from from top. 12.How to sort process w.r.t memory utilization factor. 13.How to sort p...
How to put a process in background or foreground with bg, fg, & and ^Z. How to list background processes with jobs. Subscribe to the channel! Click in like! Feel free to share the videos! Write a comment! Share it! Your participation is important!!!
This week we are controlling the processes that we learned about last week. Last week we discussed processes- what they are and how to view them. Now, let's control those. Let's open the program called gedit- a text editing program. You'll notice your shell prompt will not return until the program is closed. Press CTRL-C to interrupt the program (or terminate). This works for most command-line programs but not all. Now run gedit again with an & at the end. This says we started job number 1, with a PID of 3853. Running ps shows the proccess as well. If you type jobs, this will also show you that gedit is running. (one job, number 1, command gedit &). To return the process to the foreground from the terminal, type jobs to find the number, then fg %1. To terminate again, press CTRL-C. Type C...
More videos like this online at http://www.theurbanpenguin.com If you have access to a GUI Linux host then you can create many terminal windows so the time a command takes to process becomes less of an issue; however if you have to ssh to your console and you may be limited to a single logon then being able to run processes int he background becomes important once again
Process Control 3 - Part 3 looks at Forking, bg, fg and jobs. In this 5-part series; ps, bg, fg, jobs, nice, renice, top, kill and killall.
If you are serious about gaining your Linux Essentials certification you can gain a heavily discounted price to my Linux Essentials course via this link: https://www.udemy.com/learning-linux-essentials-taking-your-first-steps-in-linux/?couponCode=youtube-video More videos like this online at http://www.theurbanpenguin.com Learning to manage processes is essential to effective administration of your Linux host. The PS command . /bin/ps can be used to view processes and the kill command is used to send signals tp, niot just to kill, the process