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In this video, we'll go over the steps necessary to write,

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build and execute c++ programs

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from the command line on a mac.

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All we really need is a terminal session and an editor.

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Now as far as the editor is concerned, there are a bunch of editors out there. Some of

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them are free, some of them are paid editors.

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The one I'm going to use in this example is called Atom.

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And you can download it from the internet.

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And it's absolutely free. And it's a fine text editor.

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Now before I do that, I'm going to create a folder on my desktop.

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And I'm going to call it cpp projects.

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And within that folder, I'm going to create another folder called project1.

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And this is where we're going to store our source files. Okay.

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So now what we need is we need an editor and we need a terminal window.

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So let's create both of them first. Let's, create the terminal session.

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So we'll go to spotlight search and type terminal and press enter.

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And what I'm going to do is I'm going to move this terminal over here on the right.

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So that it's right docked just perfectly.

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And I'm going to run the Atom editor now. Again, you can run any editor you like.

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And there's the Atom editor, and I'll close down some of these tabs here

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so that we're here from scratch perfect.

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And again, I'm going to just dock this over here on the left side.

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Okay. So now what we want to do is we want to create a file

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in that folder that we just created. So let's go to file,

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new file,

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and it's going to be c++ file. So I'm going to save this.

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Right now so that Atom knows that it's a c++ file. I'm going to say file,

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save as

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and I want to put this on my desktop,

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in my cpp projects, project1 folder.

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And I want to name the file main.cpp.

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That's it. I'll save it and now we can start typing our c++ program.

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It's really straightforward that simple hello world program is what we're going to write.

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So we're going to say pound include,

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and you can see now that we've saved it as a .cpp file,

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Atom knows that it's c++

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so it's going to allow us to -- it's going to help us out with the

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code highlighting and syntax highlighting.

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So I'm going to include iostream,

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then I'm going to have my main. I'll say int main

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open close parents

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and open curly, which it completes for me.

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And now here all I'm going to say is std::

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cout then followed by the insertion operator,

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which is the two << signs together. And I'll just say

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any string.

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I'll just say hello mac command line.

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And I'll terminate that string.

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And then I'll put a new line at the end. So that the cursor goes to the next line when we do the output.

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So that's endl. And we'll return 0.

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That's it. That's the program. We'll save it.

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Now we need to go over to our terminal to compile and run it.

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When you open up the terminal, it defaults in your home directory.

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So you can see if you type pwd that prints the working directory,

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which is users followed by your username

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that's not where I want to be. I want to be in the desktop folder that we created,

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so we can use the cd command to change directory.

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And I'll just type desktop and you can press tab to auto complete.

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So now I'm in the desktop directory,

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then I want to go into my cpp projects directory and finally into my project1 directory,

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that's where I'm at. Now if I want to know what's in there, you can just type

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LS, which gives you a file listing.

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And you can see there's main.cpp.That's this file we just created in the editor.

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What we want to do now is we want to compile this file.

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So what we want to do is we want to type g++

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that's the name of the compiler that'll execute the compiler.

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Then we want to provide the compiler the same switches that we did in the IDE.

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So we'll say -Wall.

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So that turns on all warnings. Then we want to write -

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std=c++14,

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that'll tell us tell it to use modern c++ the 14 standard.

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Now we tell it what files you want to compile.

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In this case, I only have one, main.cpp.

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If you have more than one, you would just list them all separated by spaces.

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But here, we've got main.cpp.

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That's it. That's all you need to do. You press enter,

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we get no error messages. No news is good news.

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We'll do an LS again, and you can see that now we've got a new file created

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called a .out.

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That's the default executable file's name when you don't provide a name.

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In order to run this, you just type ./a.out.

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When I press enter, we should see hello mac command line.

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That's exactly what we see. That's this statement right here executing.

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It's as simple as that.

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Now if you don't like the a.out, you want to provide your own file name.

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You can come up and what I'm doing here is I'm pressing the up arrow

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and the down arrow. You can see it's going through what I've typed.

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So you want to go back to the statement where you ran the compiler

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and just type a -o and whatever name you want

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your executable to be. And you press enter.

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Now if we do a directory listing, you can see that main is there. If you want to run main

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./main.

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And that's it. We've created a file,

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a c++ program.

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We compiled it, and we ran it using only the command line,

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no IDEs.

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And as I mentioned, there's a whole bunch of editors out there. You can use Atom, brackets,

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text wrangler, text mate,

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sublime. And there's a bunch much more you can just do a search

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on google, and you can come up with a bunch of examples of text editors.

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Okay. So let's talk about compiler errors now.

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I'm going to clear the screen here, and I can do that in the terminal by just typing clear.

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And let's get rid of that semicolon at the end here.

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Now if I run the compiler again,

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you can see I got a clean compile.

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That makes no sense because I created an error here by removing the semicolon.

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Well, the issue is that I never saved this file.

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When you work with the IDEs, the IDEs sync everything up.

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So they realize that your source code has changed.

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So they're going to compile the latest version of it.

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Here these two are two separate programs and they're not synced.

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You're the person that has to sync them together by making sure you save it.

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So in this case, I'm going to come over here and do file save

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or command s.

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Now when I come back here and compile again, I'll see the error,

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which says I'm missing a semicolon. So I'll add that semicolon.

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If I put a semicolon in here at the end of iostream,

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which I should not have, I'll save it.

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And then I'll go compile it again.

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You can see there's an extra token at the end of the line. It's complaining about it.

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So I can go back here,

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command s again to save, and I can recompile. This time I'll get a clean compile.

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And I can run my main.

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That's it it's as simple as that.

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If you don't have the resources to run an IDE or you don't like the IDE or you feel

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the IDE is confusing you and not really allowing you to focus on the c++,

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this is a great alternative, pretty easy, pretty fast.

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And it will be in business real quick.