computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes, and development of both hardware and software. Computing has scientific, e ...

, a status key is a

keyboard Keyboard may refer to: Text input * Keyboard, part of a typewriter * Computer keyboard ** Keyboard layout, the software control of computer keyboards and their mapping ** Keyboard technology, computer keyboard hardware and firmware Music * Musi ...

key that causes an

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...

and/or a

program Program, programme, programmer, or programming may refer to: Business and management * Program management, the process of managing several related projects * Time management * Program, a part of planning Arts and entertainment Audio * Progra ...

to output status information on a

terminal Terminal may refer to: Computing Hardware * Terminal (electronics), a device for joining electrical circuits together * Terminal (telecommunication), a device communicating over a line * Computer terminal, a set of primary input and output dev ...

when it is pressed. In the event that a program on a terminal produces no indications that it is running, typing the status key will reveal the program's state and activity. Older implementations produced only a quick one-line status report for the current job when the status key was pressed. Newer implementations support sending a

signal In signal processing, a signal is a function that conveys information about a phenomenon. Any quantity that can vary over space or time can be used as a signal to share messages between observers. The ''IEEE Transactions on Signal Processing'' ...

to the current process to allow the application to report on status as well.

Implementations

Several different operating systems have a status key feature.

DEC RSTS/E

RSTS/E RSTS () is a multi-user time-sharing operating system developed by Digital Equipment Corporation (DEC, now part of Hewlett-Packard) for the PDP-11 series of 16-bit minicomputers. The first version of RSTS (RSTS-11, Version 1) was implemented in 1 ...

is documented as having a status key at least as far back as 1977 and it continued to have one into at least the 1980s. Typing the status key results in output that is represented by the following example: 18 GARP::KB32 SYSTAT+BAS4F ^C(0R) 11(16)K+ 16K 3.3(+5)

DEC TOPS-10

TOPS-10 TOPS-10 System (''Timesharing / Total Operating System-10'') is a discontinued operating system from Digital Equipment Corporation (DEC) for the PDP-10 (or DECsystem-10) mainframe computer family. Launched in 1967, TOPS-10 evolved from the earlier ...

when the CTRL/T (control-T) key is pressed, the

monitor Monitor or monitor may refer to: Places * Monitor, Alberta * Monitor, Indiana, town in the United States * Monitor, Kentucky * Monitor, Oregon, unincorporated community in the United States * Monitor, Washington * Monitor, Logan County, West ...

prints status information pertaining to the job on the terminal. Typing CTRL/T displays a job's progress without interrupting its execution. No representation of a control-t character is displayed on the terminal, just the status information. DAY: :05:43 RUN:0.48 RD:75 WR:8 SOS 12+19p ^C Ctx:1 PC:400275 ''Incremental'' values in the table below indicate that the value is the accumulation since login or last CTRL/T whichever was shortest.

DEC TOPS-20

TOPS-20 The TOPS-20 operating system by Digital Equipment Corporation (DEC) is a proprietary OS used on some of DEC's 36-bit mainframe computers. The Hardware Reference Manual was described as for "DECsystem-10/DECSYSTEM-20 Processor" (meaning the DEC PDP- ...

reports a shorter list of information than its predecessors: 09:36:35 TEST Running at 404157 Used 0:00:35.8 in 0:30:39, Load 4.04

MIT ITS

ITS copied the idea from

, but used the key sequence . 19:29:10 3 RMS HACTRN EMACS1 130566

VSI OpenVMS

OpenVMS OpenVMS, often referred to as just VMS, is a multi-user, multiprocessing and virtual memory-based operating system. It is designed to support time-sharing, batch processing, transaction processing and workstation applications. Customers using Ope ...

has a status key which can be customized and works with remote processes. The default output includes these items: NODE22::SMITH 16:21:04 (DCL) CPU=00:03:29.39 PF=14802 IO=18652 MEM=68

BSD UNIX

4.3BSD-Reno and BSD systems derived from that version and

OSF/1 OSF/1 is a variant of the Unix operating system developed by the Open Software Foundation during the late 1980s and early 1990s. OSF/1 is one of the first operating systems to have used the Mach kernel developed at Carnegie Mellon University, and ...

have a status key which defaults to Ctrl-T and can be assigned to any key. It sends SIGINFO to the current process which is ignored by default but can be configured to call a function which can display status information from the program. load: 0.10 cmd: sleep 1594 anslp1.33r 0.00u 0.00s 0% 1864k

Apple macOS

Because XNU has a

FreeBSD FreeBSD is a free and open-source Unix-like operating system descended from the Berkeley Software Distribution (BSD), which was based on Research Unix. The first version of FreeBSD was released in 1993. In 2005, FreeBSD was the most popular ...

kernel which has been modified to be a Mach server process, the terminal driver includes a status key which is inherited. load: 3.04 cmd: sleep 719 waiting 0.00u 0.00s

References

{{reflist Computer keys System monitors