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The "head and tail commands" Lesson is part of the full, Introduction to Bash, VIM & Regex course featured in this preview video. Here's what you'd learn in this lesson:

James reviews the head and tail commands. Head command prints the first part of a file while the tail command reads from the end of the file.


Transcript from the "head and tail commands" Lesson

>> James Halliday: Now I just wanna cover some more utilities that you're very likely to find on pretty much any Unix system. So the first one is called head, we've used it a few times already. It prints out starting from the beginning of a file, it prints out a certain number of characters or a certain number of lines starting from the beginning of a file.

So if I do head -n5 moby-dick.txt, I see the first five lines. There's also one called tail, tail is like head but it starts at the end, and it reads backwards. So if I want the last five lines, I can do that. Head and tail, if you don't specify a file name, we'll read from standard in by default.

So if you have other commands, that's like spammy, and you only care about the last bit or the first bit, see we have our git log, right. If I only want the first line of output, I can pipe into head-n1, and I get just the commit message, which is kind of handy.

>> James Halliday: If you read the man page for head, there's different options, -n gives you the number of lines, but if you want the number of characters or bytes you can use -c. So for example if I do had -c 10, I just get the first 10 characters. And you can see that it doesn't give a new line there so you gotta hit enter if you want.

Just type it in, or you could do that and that would add a new line. Get a little more into how to chain tick of a commands in a bit.

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