c-runner

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

v2.0.0·

Visitors:

bash

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

🔨 Compiling main.c...

✅ Compiled in 38ms

▶️ Running...

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Features

Everything you need

No config required to get started.

Smart Compilation

Direct compilation for single files, cached incremental builds for projects — only recompiles what changed.

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 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 + 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 at a glance.

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

c-runner run

Compile all .c files in the project and run the executable.

Watch project

c-runner run --watch

Auto-recompile the entire project on any file change.

Run a single file

c-runner main.c

Compile and run a .c file. Creates it with starter code if missing or empty.

Watch a single file

c-runner main.c --watch

Auto-recompile on every save. Creates starter code if file is missing or empty.

Stdin from file

c-runner main.c -i input.txt

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

Capture output

c-runner main.c -o output.txt

Write program output to output.txt. Overwrites on every run.

Full file I/O + watch

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

Watch mode with file I/O — reruns on .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 to a temp binary, runs, cleans up. Creates starter code if file is missing or empty.
→Project mode — compiles all .c files, outputs binary named after main.c into build_dir.
→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