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(upbeat music)

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- [Instructor] Here's your little challenge

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for device files.

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If you do a long list on /dev/null,

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you'll see its major and minor number.

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Can you find other device files

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that have the same major number

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that are essentially implemented

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by the same driver in the kernel?

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Also with /dev/null,

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you're probably familiar with redirecting output

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to /dev/null, which essentially throws it away.

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Can you read from /dev/null?

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What happens if you try to read from /dev/null?

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Do you get an error?

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Give that a try. Use strace to figure out what happens

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when you cat /dev/null.

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Good luck.