COMPUTER SCIENCE AND ENGINEERING
UNIX
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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External command
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Internal command
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kernal
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shell
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Detailed explanation-1: -An internal command is the MS-DOS command stored in system memory and loaded from command.com or cmd.exe. Internal commands include MD, DATE, COPY, CD, TIME, COPR CON, TYPE, etc.
Detailed explanation-2: -’Sys’ is not an internal command in DOS.
Detailed explanation-3: -Internal commands are commands that are already loaded in the system. They can be executed any time and are independent. On the other hand, external commands are loaded when the user requests for them. Internal commands don’t require a separate process to execute them. External commands will have an individual process.
Detailed explanation-4: -Internal Command: Internal commands are something which is built into the shell. For the shell built in commands, the execution speed is really high. It is because no process needs to be spawned for executing it. For example, when using the “cd” command, no process is created.