-->

To create and run a C program using Visual Studio 2019 Once Visual Studio is started, click Z reate a new project. Select Empty Project and click Next. Visual C# and Databases - 2019 Edition: A Step-By-Step Database Programming Tutorial using Visual Studio 2019 Philip Conrod. 4.3 out of 5 stars 8. Prerequisites for running a C program in Visual Studio Code. We should have a basic knowledge of.

Visual C++ includes a C compiler that you can use to create everything from basic console programs to full Windows Desktop applications, mobile apps, and more.

This walkthrough shows how to create a basic, 'Hello, World'-style C program by using a text editor, and then compile it on the command line. If you'd rather work in C++ on the command line, see Walkthrough: Compiling a Native C++ Program on the Command Line. If you'd like to try the Visual Studio IDE instead of using the command line, see Walkthrough: Working with Projects and Solutions (C++) or Using the Visual Studio IDE for C++ Desktop Development.

Prerequisites

To complete this walkthrough, you must have installed either Visual Studio and the optional Visual C++ components, or the Build Tools for Visual Studio.

Visual Studio is a powerful integrated development environment that supports a full-featured editor, resource managers, debuggers, and compilers for many languages and platforms. For information on these features and how to download and install Visual Studio, including the free Visual Studio Community edition, see Install Visual Studio.

The Build Tools for Visual Studio version of Visual Studio installs only the command-line toolset, the compilers, tools, and libraries you need to build C and C++ programs. It's perfect for build labs or classroom exercises and installs relatively quickly. To install only the command-line toolset, download Build Tools for Visual Studio from the Visual Studio downloads page and run the installer. In the Visual Studio installer, select the C++ build tools workload, and choose Install.

Before you can build a C or C++ program on the command line, you must verify that the tools are installed, and that you can access them from the command line. Visual C++ has complex requirements for the command-line environment to find the tools, headers, and libraries it uses. You can't use Visual C++ in a plain command prompt window without some preparation. You need a developer command prompt window, which is a regular command prompt window that has all the required environment variables set. Fortunately, Visual C++ installs shortcuts for you to launch developer command prompts that have the environment set up for command line builds. Unfortunately, the names of the developer command prompt shortcuts and where they're located are different in almost every version of Visual C++ and on different versions of Windows. Your first walkthrough task is to find the right shortcut to use.

Note

A developer command prompt shortcut automatically sets the correct paths for the compiler and tools, and for any required headers and libraries. Some of these values are different for each build configuration. You must set these environment values yourself if you don't use one of the shortcuts. For more information, see Set the Path and Environment Variables for Command-Line Builds. Because the build environment is complex, we strongly recommend you use a developer command prompt shortcut instead of building your own.

Visual

These instructions vary depending on which version of Visual Studio you are using. To see the documentation for your preferred version of Visual Studio, use the Version selector control. It's found at the top of the table of contents on this page.

Open a developer command prompt in Visual Studio 2019

If you have installed Visual Studio 2019 on Windows 10, open the Start menu, and then scroll down and open the Visual Studio 2019 folder (not the Visual Studio 2019 app). Choose Developer Command Prompt for VS 2019 to open the command prompt window.

If you're using a different version of Windows, look in your Start menu or Start page for a Visual Studio tools folder that contains a developer command prompt shortcut. You can also use the Windows search function to search for 'developer command prompt' and choose one that matches your installed version of Visual Studio. Use the shortcut to open the command prompt window.

Open a developer command prompt in Visual Studio 2017

If you have installed Visual Studio 2017 on Windows 10, open the Start menu, and then scroll down and open the Visual Studio 2017 folder (not the Visual Studio 2017 app). Choose Developer Command Prompt for VS 2017 to open the command prompt window.

If you're running a different version of Windows, look in your Start menu or Start page for a Visual Studio tools folder that contains a developer command prompt shortcut. You can also use the Windows search function to search for 'developer command prompt' and choose one that matches your installed version of Visual Studio. Use the shortcut to open the command prompt window.

Open a developer command prompt in Visual Studio 2015

If you have installed Microsoft Visual C++ Build Tools 2015 on Windows 10, open the Start menu, and then scroll down and open the Visual C++ Build Tools folder. Choose Visual C++ 2015 x86 Native Tools Command Prompt to open the command prompt window.

If you're running a different version of Windows, look in your Start menu or Start page for a Visual Studio tools folder that contains a developer command prompt shortcut. You can also use the Windows search function to search for 'developer command prompt' and choose one that matches your installed version of Visual Studio. Use the shortcut to open the command prompt window.

Next, verify that the Visual C++ developer command prompt is set up correctly. In the command prompt window, enter cl and verify that the output looks something like this:

There may be differences in the current directory or version numbers, depending on the version of Visual C++ and any updates installed. If the above output is similar to what you see, then you're ready to build C or C++ programs at the command line.

Note

If you get an error such as 'cl' is not recognized as an internal or external command, operable program or batch file,' error C1034, or error LNK1104 when you run the cl command, then either you are not using a developer command prompt, or something is wrong with your installation of Visual C++. You must fix this issue before you can continue.

If you can't find the developer command prompt shortcut, or if you get an error message when you enter cl, then your Visual C++ installation may have a problem. If you're using Visual Studio 2017 or later, try reinstalling the Desktop development with C++ workload in the Visual Studio installer. For details, see Install C++ support in Visual Studio. Or, reinstall the Build Tools from the Visual Studio downloads page. Don't go on to the next section until this works. For more information about installing and troubleshooting Visual Studio, see Install Visual Studio.

Note

Depending on the version of Windows on the computer and the system security configuration, you might have to right-click to open the shortcut menu for the developer command prompt shortcut and then choose Run as Administrator to successfully build and run the program that you create by following this walkthrough.

Create a C source file and compile it on the command line

  1. In the developer command prompt window, enter cd c: to change the current working directory to the root of your C: drive. Next, enter md c:simple to create a directory, and then enter cd c:simple to change to that directory. This directory will hold your source file and the compiled program.

  2. Enter notepad simple.c at the developer command prompt. In the Notepad alert dialog that pops up, choose Yes to create a new simple.c file in your working directory.

  3. In Notepad, enter the following lines of code:

  4. On the Notepad menu bar, choose File > Save to save simple.c in your working directory.

  5. Switch back to the developer command prompt window. Enter dir at the command prompt to list the contents of the c:simple directory. You should see the source file simple.c in the directory listing, which looks something like:

    The dates and other details will differ on your computer. If you don't see your source code file, simple.c, make sure you've changed to the c:simple directory you created, and in Notepad, make sure that you saved your source file in this directory. Also make sure that you saved the source code with a .c file name extension, not a .txt extension.

  6. To compile your program, enter cl simple.c at the developer command prompt.

    You can see the executable program name, simple.exe, in the lines of output information that the compiler displays:

    Note

    If you get an error such as 'cl' is not recognized as an internal or external command, operable program or batch file,' error C1034, or error LNK1104, your developer command prompt is not set up correctly. For information on how to fix this issue, go back to the Open a developer command prompt section.

    Note

    If you get a different compiler or linker error or warning, review your source code to correct any errors, then save it and run the compiler again. For information about specific errors, use the search box at the top of this page to look for the error number.

  7. To run your program, enter simple at the command prompt.

    The program displays this text and then exits:

    Congratulations, you've compiled and run a C program by using the command line.

Next steps

This 'Hello, World' example is about as simple as a C program can get. Real world programs have header files and more source files, link in libraries, and do useful work.

You can use the steps in this walkthrough to build your own C code instead of typing the sample code shown. You can also build many C code sample programs that you find elsewhere. To compile a program that has additional source code files, enter them all on the command line, like:

C Programming In Visual Studio 2019

cl file1.c file2.c file3.c

The compiler outputs a program called file1.exe. To change the name to program1.exe, add an /out linker option:

cl file1.c file2.c file3.c /link /out:program1.exe

And to catch more programming mistakes automatically, we recommend you compile by using either the /W3 or /W4 warning level option:

cl /W4 file1.c file2.c file3.c /link /out:program1.exe

The compiler, cl.exe, has many more options you can apply to build, optimize, debug, and analyze your code. For a quick list, enter cl /? at the developer command prompt. You can also compile and link separately and apply linker options in more complex build scenarios. For more information on compiler and linker options and usage, see C/C++ Building Reference.

You can use NMAKE and makefiles, or MSBuild and project files to configure and build more complex projects on the command line. For more information on using these tools, see NMAKE Reference and MSBuild.

The C and C++ languages are similar, but not the same. The Microsoft C/C++ compiler (MSVC) uses a simple rule to determine which language to use when it compiles your code. By default, the MSVC compiler treats all files that end in .c as C source code, and all files that end in .cpp as C++ source code. To force the compiler to treat all files as C non-dependent of file name extension, use the /TC compiler option.

MSVC is compatible with the ISO C99 standard, but not strictly compliant. In most cases, portable C code will compile and run as expected. Visual C++ provides support for the changes in ISO C11/C17. To compile with C11/C17 support, use the compiler flag /std:c11 or /std:c17. Certain library functions and POSIX function names are deprecated by MSVC. The functions are supported, but the preferred names have changed. For more information, see Security Features in the CRT and Compiler Warning (level 3) C4996.

See also

Walkthrough: Creating a Standard C++ Program (C++)
C Language Reference
Projects and build systems
Compatibility

In this tutorial, you configure Visual Studio Code to use the GCC C++ compiler (g++) and GDB debugger from mingw-w64 to create programs that run on Windows.

After configuring VS Code, you will compile and debug a simple Hello World program in VS Code. This tutorial does not teach you about GCC, GDB, Mingw-w64, or the C++ language. For those subjects, there are many good resources available on the Web.

If you have any problems, feel free to file an issue for this tutorial in the VS Code documentation repository.

Prerequisites

To successfully complete this tutorial, you must do the following steps:

  1. Install Visual Studio Code.

  2. Install the C/C++ extension for VS Code. You can install the C/C++ extension by searching for 'c++' in the Extensions view (⇧⌘X (Windows, Linux Ctrl+Shift+X)).

  3. Install Mingw-w64 via the SourceForge website. Click Mingw-w64 to download the Windows Mingw-w64 installer.

    1. Run the installer.
    2. For Architecture select x86_64 and then select Next.
    3. On the Installation Folder page, use the default installation folder. Copy the location as you will need it later.
    4. Select Next to start the installation.
  4. Add the path to your Mingw-w64 bin folder to the Windows PATH environment variable by using the following steps:

    1. In the Windows search bar, type 'settings' to open your Windows Settings.
    2. Search for Edit environment variables for your account.
    3. Choose the Path variable and then select Edit.
    4. Select New and add the Mingw-w64 destination folder path to the system path. The exact path depends on which version of Mingw-w64 you have installed and where you installed it. If you used the settings above to install Mingw-w64, then add this to the path: C:Program Filesmingw-w64x86_64-8.1.0-posix-seh-rt_v6-rev0mingw64bin.
    5. Select OK to save the updated PATH. You will need to reopen any console windows for the new PATH location to be available.

Check your MinGW installation

To check that your Mingw-w64 tools are correctly installed and available, open a new Command Prompt and type:

If you don't see the expected output or g++ or gdb is not a recognized command, check your installation (Windows Control Panel > Programs) and make sure your PATH entry matches the Mingw-w64 binary location where the compilers are located.

Create Hello World

From a Windows command prompt, create an empty folder called projects where you can place all your VS Code projects. Then create a sub-folder called helloworld, navigate into it, and open VS Code in that folder by entering the following commands:

Run C Code In Visual Studio 2019

The 'code .' command opens VS Code in the current working folder, which becomes your 'workspace'. As you go through the tutorial, you will see three files created in a .vscode folder in the workspace:

  • tasks.json (build instructions)
  • launch.json (debugger settings)
  • c_cpp_properties.json (compiler path and IntelliSense settings)

Add a source code file

In the File Explorer title bar, select the New File button and name the file helloworld.cpp.

Add hello world source code

Now paste in this source code:

Now press ⌘S (Windows, Linux Ctrl+S) to save the file. Notice how the file you just added appears in the File Explorer view (⇧⌘E (Windows, Linux Ctrl+Shift+E)) in the side bar of VS Code:

You can also enable Auto Save to automatically save your file changes, by checking Auto Save in the main File menu.

The Activity Bar on the far left lets you open different views such as Search, Source Control, and Run. You'll look at the Run view later in this tutorial. You can find out more about the other views in the VS Code User Interface documentation.

Note: When you save or open a C++ file, you may see a notification from the C/C++ extension about the availability of an Insiders version, which lets you test new features and fixes. You can ignore this notification by selecting the X (Clear Notification).

Explore IntelliSense

In your new helloworld.cpp file, hover over vector or string to see type information. After the declaration of the msg variable, start typing msg. as you would when calling a member function. You should immediately see a completion list that shows all the member functions, and a window that shows the type information for the msg object:

You can press the Tab key to insert the selected member; then, when you add the opening parenthesis, you will see information about any arguments that the function requires.

Build helloworld.cpp

Next, you'll create a tasks.json file to tell VS Code how to build (compile) the program. This task will invoke the g++ compiler to create an executable file based on the source code.

From the main menu, choose Terminal > Configure Default Build Task. In the dropdown, which will display a tasks dropdown listing various predefined build tasks for C++ compilers. Choose g++.exe build active file, which will build the file that is currently displayed (active) in the editor.

This will create a tasks.json file in a .vscode folder and open it in the editor.

Your new tasks.json file should look similar to the JSON below:

The command setting specifies the program to run; in this case that is g++. The args array specifies the command-line arguments that will be passed to g++. These arguments must be specified in the order expected by the compiler. This task tells g++ to take the active file (${file}), compile it, and create an executable file in the current directory (${fileDirname}) with the same name as the active file but with the .exe extension (${fileBasenameNoExtension}.exe), resulting in helloworld.exe for our example.

Note: You can learn more about tasks.json variables in the variables reference.

The label value is what you will see in the tasks list; you can name this whatever you like.

The 'isDefault': true value in the group object specifies that this task will be run when you press ⇧⌘B (Windows, Linux Ctrl+Shift+B). This property is for convenience only; if you set it to false, you can still run it from the Terminal menu with Tasks: Run Build Task.

Running the build

  1. Go back to helloworld.cpp. Your task builds the active file and you want to build helloworld.cpp.

  2. To run the build task defined in tasks.json, press ⇧⌘B (Windows, Linux Ctrl+Shift+B) or from the Terminal main menu choose Run Build Task.

  3. When the task starts, you should see the Integrated Terminal panel appear below the source code editor. After the task completes, the terminal shows output from the compiler that indicates whether the build succeeded or failed. For a successful g++ build, the output looks something like this:

  4. Create a new terminal using the + button and you'll have a new terminal with the helloworld folder as the working directory. Run dir and you should now see the executable helloworld.exe.

  5. You can run helloworld in the terminal by typing helloworld.exe (or .helloworld.exe if you use a PowerShell terminal).

Note: You might need to press Enter a couple of times initially to see the PowerShell prompt in the terminal. This issue should be fixed in a future release of Windows.

Modifying tasks.json

You can modify your tasks.json to build multiple C++ files by using an argument like '${workspaceFolder}*.cpp' instead of ${file}. This will build all .cpp files in your current folder. You can also modify the output filename by replacing '${fileDirname}${fileBasenameNoExtension}.exe' with a hard-coded filename (for example '${workspaceFolder}myProgram.exe').

Debug helloworld.cpp

Next, you'll create a launch.json file to configure VS Code to launch the GDB debugger when you press F5 to debug the program.

  1. From the main menu, choose Run > Add Configuration... and then choose C++ (GDB/LLDB).
  2. You'll then see a dropdown for various predefined debugging configurations. Choose g++.exe build and debug active file.

VS Code creates a launch.json file, opens it in the editor, and builds and runs 'helloworld'.

Visual studio create c project

The program setting specifies the program you want to debug. Here it is set to the active file folder ${fileDirname} and active filename with the .exe extension ${fileBasenameNoExtension}.exe, which if helloworld.cpp is the active file will be helloworld.exe.

By default, the C++ extension won't add any breakpoints to your source code and the stopAtEntry value is set to false.

Change the stopAtEntry value to true to cause the debugger to stop on the main method when you start debugging.

Note: The preLaunchTask setting is used to specify task to be executed before launch. Make sure it is consistent with the tasks.json file label setting.

Start a debugging session

  1. Go back to helloworld.cpp so that it is the active file.
  2. Press F5 or from the main menu choose Run > Start Debugging. Before you start stepping through the source code, let's take a moment to notice several changes in the user interface:
  • The Integrated Terminal appears at the bottom of the source code editor. In the Debug Output tab, you see output that indicates the debugger is up and running.

  • The editor highlights the first statement in the main method. This is a breakpoint that the C++ extension automatically sets for you:

  • The Run view on the left shows debugging information. You'll see an example later in the tutorial.

  • At the top of the code editor, a debugging control panel appears. You can move this around the screen by grabbing the dots on the left side.

Step through the code

Now you're ready to start stepping through the code.

  1. Click or press the Step over icon in the debugging control panel.

    This will advance program execution to the first line of the for loop, and skip over all the internal function calls within the vector and string classes that are invoked when the msg variable is created and initialized. Notice the change in the Variables window on the left.

    In this case, the errors are expected because, although the variable names for the loop are now visible to the debugger, the statement has not executed yet, so there is nothing to read at this point. The contents of msg are visible, however, because that statement has completed.

  2. Press Step over again to advance to the next statement in this program (skipping over all the internal code that is executed to initialize the loop). Now, the Variables window shows information about the loop variables.

  3. Press Step over again to execute the cout statement. (Note that as of the March 2019 release, the C++ extension does not print any output to the Debug Console until the loop exits.)

  4. If you like, you can keep pressing Step over until all the words in the vector have been printed to the console. But if you are curious, try pressing the Step Into button to step through source code in the C++ standard library!

    To return to your own code, one way is to keep pressing Step over. Another way is to set a breakpoint in your code by switching to the helloworld.cpp tab in the code editor, putting the insertion point somewhere on the cout statement inside the loop, and pressing F9. A red dot appears in the gutter on the left to indicate that a breakpoint has been set on this line.

    Then press F5 to start execution from the current line in the standard library header. Execution will break on cout. If you like, you can press F9 again to toggle off the breakpoint.

    When the loop has completed, you can see the output in the Integrated Terminal, along with some other diagnostic information that is output by GDB.

Set a watch

Sometimes you might want to keep track of the value of a variable as your program executes. You can do this by setting a watch on the variable.

  1. Place the insertion point inside the loop. In the Watch window, click the plus sign and in the text box, type word, which is the name of the loop variable. Now view the Watch window as you step through the loop.

  2. Add another watch by adding this statement before the loop: int i = 0;. Then, inside the loop, add this statement: ++i;. Now add a watch for i as you did in the previous step.

  3. To quickly view the value of any variable while execution is paused on a breakpoint, you can hover over it with the mouse pointer.

C/C++ configurations

If you want more control over the C/C++ extension, you can create a c_cpp_properties.json file, which will allow you to change settings such as the path to the compiler, include paths, C++ standard (default is C++17), and more.

You can view the C/C++ configuration UI by running the command C/C++: Edit Configurations (UI) from the Command Palette (⇧⌘P (Windows, Linux Ctrl+Shift+P)).

This opens the C/C++ Configurations page. When you make changes here, VS Code writes them to a file called c_cpp_properties.json in the .vscode folder.

Here, we've changed the Configuration name to GCC, set the Compiler path dropdown to the g++ compiler, and the IntelliSense mode to match the compiler (gcc-x64)

Visual Studio Code places these settings in .vscodec_cpp_properties.json. If you open that file directly, it should look something like this:

You only need to add to the Include path array setting if your program includes header files that are not in your workspace or in the standard library path.

Compiler path

The extension uses the compilerPath setting to infer the path to the C++ standard library header files. When the extension knows where to find those files, it can provide features like smart completions and Go to Definition navigation.

The C/C++ extension attempts to populate compilerPath with the default compiler location based on what it finds on your system. The extension looks in several common compiler locations.

The compilerPath search order is:

  • First check for the Microsoft Visual C++ compiler
  • Then look for g++ on Windows Subsystem for Linux (WSL)
  • Then g++ for Mingw-w64.

C Programming Language Visual Studio 2019

If you have Visual Studio or WSL installed, you may need to change compilerPath to match the preferred compiler for your project. For example, if you installed Mingw-w64 version 8.1.0 using the i686 architecture, Win32 threading, and sjlj exception handling install options, the path would look like this: C:Program Files (x86)mingw-w64i686-8.1.0-win32-sjlj-rt_v6-rev0mingw64bing++.exe.

C Compiler In Visual Studio 2019

Next steps

C Code In Visual Studio 2019

  • Explore the VS Code User Guide.
  • Review the Overview of the C++ extension.
  • Create a new workspace, copy your .vscode JSON files to it, adjust the necessary settings for the new workspace path, program name, and so on, and start coding!