Tout

tout is a lightweight Unix utility that executes a command with a configurable timeout.

Unlike many simple timeout implementations, tout runs the target command in its own process group, ensuring that child processes are also terminated when the timeout expires.

Features

• Execute any command with a timeout.
• Terminates the entire process tree on timeout.
• Lightweight and dependency-free.
• Simple command-line interface.
• POSIX compliant.

Installation

Clone the repository and build it:

git clone https://github.com/<your-username>/tout.git
cd tout
make

The binary will be available in the project root.

Usage

tout <timeout> <command> [arguments...]

Examples

Run a command for at most 5 seconds:

tout 5 sleep 10

Run a Python script with a 30-second timeout:

tout 30 python script.py

Run Bazel formatting with a 2-second timeout:

tout 2 bazel run format

Display help:

tout --help

Exit Status

• Returns the exit code of the executed command if it finishes before the timeout.
• Returns a non-zero exit status if the command fails.
• Returns after terminating the command when the timeout expires.

Why another timeout utility?

tout was created as a small educational project to explore Unix process management, including:

• Process creation with fork()
• Program execution with execvp()
• Signal handling
• Process groups
• waitpid()
• Timeouts using alarm()

License

This project is licensed under the MIT License.