c-runner

The fastest way to compile and run C/C++ code — single files or full projects, with live watch mode.

v2.2.0·

Visitors:

bash

$ c-runner main.c -i input.txt -o output.txt --watch

🔨 Compiling main.c...

✅ Compiled in 38ms

▶️ Running...

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$ █

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Features

Everything you need

No config required to get started.

C & C++ Support

Compile .c files with gcc, .cpp files with g++. Automatic compiler detection based on file extensions.

Watch Mode

Auto-recompile on file changes using inotifywait, fswatch, entr, or built-in polling as fallback.

File I/O Mode

Pipe input.txt into stdin and capture program output to output.txt — perfect for testing scanf-based programs.

Auto Starter

Missing or empty .c or .cpp file? c-runner creates it with Hello World starter code and runs it immediately.

Configurable

Use config.yml or environment variables to customize source, build directories, and file I/O per project.

Clean Execution

Single files compile to a temp binary, run, then clean up automatically — zero leftover files.

Installation

Get up and running in under a minute.

1. Install dependencies

sudo apt update                                  # refresh package list
sudo apt install build-essential inotify-tools   # gcc, g++ + file watcher for watch mode

2. Download & install c-runner

wget https://c-runner.vercel.app/c-runner        # download the binary
chmod +x c-runner                                # make it executable
sudo mv c-runner /usr/local/bin/                 # install globally
c-runner --version                               # verify installation

Tutorial

See c-runner in action.

Usage

All available commands organized by language.

General Commands

Version

c-runner --version

Display version and author information.

Help

c-runner --help

Show all available commands and options.

Initialize config

c-runner --init

Create a config.yml with default src_dir, build_dir, and file_mode settings.

Run project (all files)

c-runner run

Compile all .c and .cpp files. Uses g++ if any .cpp files exist, otherwise gcc.

Watch project

c-runner run --watch

Auto-recompile the entire project on any .c or .cpp file change.

Run C file

c-runner main.c

Compile with gcc and run. Auto-creates file with C starter code if missing.

Watch C file

c-runner main.c --watch

Auto-recompile with gcc on every save. Creates C starter code if missing.

C with stdin

c-runner main.c -i input.txt

Pipe input.txt into stdin for scanf() — each line feeds the next scanf call.

C with output capture

c-runner main.c -o output.txt

Write printf() output to output.txt. Overwrites on every run.

C: full I/O + watch

c-runner main.c -i input.txt -o output.txt --watch

Watch mode with file I/O for C — reruns on main.c or input.txt changes.

Configuration

Customize per project with a simple YAML file.

config.yml

# GCC Build Configuration
src_dir: src
build_dir: build

# File I/O mode (optional)
# file_mode:
#   input: input.txt        # pipe this file into stdin
#   output: output.txt      # write program output to this file
#   view_terminal: true     # also print output to terminal (default: false)

input.txt

# comment lines are ignored — use them to document your inputs
10 20       # a and b

# next scanf value
300

How It Works

→Single file — compiles .c with gcc, .cpp with g++. Creates starter code if file is missing or empty.
→Project mode — compiles all .c and .cpp files. Uses g++ if any .cpp files exist, otherwise gcc.
→File I/O — CLI flags -i / -o override config.yml values.
→input.txt comments — lines starting with # are stripped before being piped to stdin.

Config Keys

src_dirSource directory (default: .)
build_dirBuild directory (default: build)
inputStdin source file (default: —)
outputStdout target file (default: —)
view_terminalAlso print to terminal (default: false)

Uninstall

Remove c-runner

sudo rm /usr/local/bin/c-runner