Run C++ and C Code

Run C++ and C Code: One-Click Compile with GCC, G++, Clang (CPP Runner, Input Panel), a VS Code extension by Zovo

Free, no sign-in, works offline. Click Run on a .c or .cpp file. The extension compiles it with the gcc, g++, clang or clang++ already on your computer and runs the program in the terminal, where scanf and cin work. Errors go to the Problems panel at the right line. An Input panel keeps test cases and shows pass or fail with a diff.

Free, MIT license. Needs VS Code 1.90.0 or newer. Extension ID zovo.zovo-run-cpp, version 0.2.2.

• The Run button in the editor title (or Ctrl+Alt+Enter, Cmd+Alt+Enter on Mac) builds and runs in one step. Build only, Run last build, Debug and Build all files in the folder are in the "..." menu.
• The Input & Tests panel takes pasted input and shows stdout, stderr, exit code, run time and peak memory. Test cases are saved per file and run together.
• A // run: -O2 -lm line at the top of a file sets flags for that file, and // args: "Hello World" 3 sets the program arguments.
• Stop ends an endless loop and every process it started. A segfault shows the signal and what it usually means.
• Spaces, &, ü or 你好 in folder and file names work. No shell ever parses your paths.

Questions people ask

Why this one

The two most installed C/C++ run extensions on the Marketplace are good and popular. These are requests and bug reports from their issue trackers that this extension handles, each checked in a real VS Code run (see Tested):

Run a file

1. Open a .c, .cpp, .cc or .cxx file.
2. Click the Run button (top right), press Ctrl+Alt+Enter (Cmd+Alt+Enter on Mac), or right-click and pick Run C/C++ File.
3. The program runs in a terminal named "Run: file.cpp". Type its input there. At the end you see the exit code, the run time and the peak memory.

The program runs with the terminal as its console, so prompts without a newline show up before cin waits, as in any shell. While it runs, the Run button turns into Stop.

The keybinding is not used by VS Code or by the two most installed runners (they use F5 to F8, Ctrl+6, Ctrl+Alt+R/B/D/A). Change it in Keyboard Shortcuts: "Run C++: Run C/C++ File".

Input & Tests panel

Open it with Run C++: Run with Input & Test Cases, or from the Run C++ tab in the bottom panel.

• Type the input and press Run with input (Ctrl+Enter in the input box).
• Save as test case stores the input and the current output as the expected output. Edit the expected output if it is wrong.
• Run all tests runs each case with a time limit (10 s, setting zovoRun.timeLimitSeconds) and shows pass or fail. A failed case shows a side-by-side line diff from the first difference.
• Compare modes: ignore spaces at line ends (default), exact, or words only (zovoRun.compareMode).
• Test cases live in .zovo-run/tests/ in your workspace, one JSON file per source file, so you can commit them.

Flags and arguments per file

// run: -O2 -lm util.c
// args: "Hello World" 3

run: adds compiler flags (and extra source files) for this file. args: sets the program arguments; quotes keep spaces together. Both are read from the first 40 lines. The defaults are -std=c++20 -Wall -Wextra -g -O0 for C++ and -std=c17 -Wall -Wextra -g -O0 for C (settings zovoRun.cppFlags, zovoRun.cFlags). C programs are linked with -lm. If the compiler is too old for C++20 or C17, the build steps down to the newest standard it knows and says so.

Errors and warnings

Compiler errors and warnings from gcc and clang go to the Problems panel with file, line and column, and notes are attached to their error. Linker errors (for example undefined reference to sqrt) show on the file with a hint (-lm, or build the whole folder). The full compiler output is in the "Run C++ and C" output channel.

Large output, endless loops, crashes

• A program that prints 1,000,000 lines does not freeze the editor. In the Input panel the first 2,000 lines are shown, all lines are counted, and Open full output opens everything in an editor tab. Output past 32 MB is counted, not kept (zovoRun.maxCapturedOutputMB).
• Stop kills the program and every process it started (fork, child programs).
• A crash shows the signal and what it usually means, for example "SIGSEGV (signal 11): the program read or wrote memory it does not own". On Windows, codes like 0xC0000005 are named too.

Compilers

gcc, g++, clang and clang++ are found on PATH. On Windows the extension also looks in C:\msys64\ucrt64\bin, C:\msys64\mingw64\bin, C:\msys64\clang64\bin, C:\MinGW\bin, C:\mingw64\bin, the WinLibs winget folder, TDM-GCC, Chocolatey MinGW, Scoop and C:\Program Files\LLVM\bin. Homebrew names like g++-14 are found too. Run C++: Pick Compiler lists what was found, with versions.

When there is no compiler, a setup page shows the official steps for your system (Xcode Command Line Tools, MSYS2 or WinLibs, your Linux package manager) and a Check again button. The extension never downloads a compiler.

Debug

Run C++: Debug C/C++ File builds with -g and starts the debugger with CodeLLDB or the C/C++ extension (gdb or lldb), whichever is installed. It adds one entry named "Debug file.cpp (Run C++)" to .vscode/launch.json (turn off with zovoRun.writeLaunchJson).

Built programs

Programs go to .zovo-run/bin/ in the workspace folder, with a .gitignore inside so git skips them, or to the system temp folder (zovoRun.outputFolder). A file is built again only when it, a header next to it, or its flags changed. Run C++: Delete Built Programs removes them.

Related tools: Open Built Program in Hex Viewer (with the free Zovo Hex Viewer), and Open Linker Map File for builds with // run: -Wl,-Map=app.map (with the free Zovo Linker Map Viewer).

Stress test and benchmark

In the Input & Tests panel under "Stress test and benchmark":

• For a stress test, pick a generator program (it gets a seed as its first argument and prints one input) and a slow reference solution. The extension runs up to 10,000 inputs and stops at the first one where your output differs, and saves it as a test case.
• Benchmark runs the current input 10 times and shows min, median and max time and peak memory.

Privacy

No network, no telemetry, no account. The extension starts only your compiler and your program. The rating question and the support links open a web page only when you click them.

Settings

License

MIT

Guides

• Run a C++ file in VS Code with one click