DEC VT52 terminal The earliest computers didn't aid interactive enter/output products, typically counting on sense switches and lights to communicate with the pc operator. This was enough for batch programs that ran one particular system at a time, often With all the programmer acting as operator.

a : a training course of conduct or contemplating Specially : an Formal or public situation the celebration line

For instance, steel wires have been employed for toughness, while aluminium or copper wires were used for conductivity.[3] Yet another variety appeared like it experienced all copper wires but inside of Each individual wire was a metal Main for strength. The steel strands were galvanized but for much better corrosion safety they could be coated with the anti-corrosion material.

In Various other devices abbreviations are computerized, such as permitting adequate of the primary people of the command identify to uniquely identify it (like SU as an abbreviation for SUPERUSER) while some might have some precise abbreviations pre-programmed (e.

In Unix-like running techniques, just one hyphen utilized in place of a file identify is often a Specific worth specifying that a plan should handle information coming from your normal input or ship info on the common output.

c traces plural : a certification of marriage d : the terms earning up a part in a very overall performance

Interactive command-line classes: Just after start, a method may possibly give an operator using an independent means to enter commands.

). A few of these capabilities had been by now supported from the DR DOS three.forty one SID86 and GEMSID. ^ Notable variation for describing the command syntax of DOS-like operating techniques: Home windows Server 2003 R2 documentation utilizes italic letters for "data which the user have to source", but Windows Server 2008 documentation employs angle brackets. Italics cannot be displayed by The interior enable command, while there's no challenge with angle brackets. ^ With the exception of ASCII artwork.

A few consultant samples of command-line selections, all concerning listing files within a directory, As an example some conventions: Running process

The posture light-weight sign aspect was originally devised through the Pennsylvania Railroad and was continued by Amtrak and adopted get more info by Metro North. Steel indications ended up hung with the catenary supports While using the letters "PB" created by a pattern of drilled holes.

Two overhead conductor rails for the same monitor. Still left, 1,200 V DC for the Uetliberg railway (the pantograph is mounted asymmetrically to collect current from this rail); right, fifteen kV AC with the Sihltal railway Some railways made use of two or a few overhead strains, commonly to hold 3-stage present.

The wiring in most countries is simply too small to permit double stack container trains. The Channel Tunnel has an prolonged peak overhead line to accommodate double-height vehicle and truck transporters.

A simple CLI will display a prompt, settle for a command line typed because of the person terminated with the Enter crucial, then execute the desired command and provide textual Show of success or mistake messages.

Although most customers think about the shell being an interactive command interpreter, it is known as a programming language wherein each statement runs a command.